EC1340 Topic 2
Carbon cycle emissions and consumptionand emissions levels and trends
Matthew A TurnerBrown University
Fall 2019
(Updated September 15 2019)
Copyright Matthew Turner 2019
Outline
1 Review
2 Carbon cycle
3 Atmospheric carbon cycle
4 Consumption and emissions
5 Emissions
6 Peak oil
7 Conclusion
Review
Last time wedescribed our endowment of climate and atmospheric CO2 anddiscussed climate models that allow us to link current climate andCO2 to future climate
The world has warmed by about 1 degree Celsius sincepreindustrial times
This warming is not uniform Poles are warming fasterPossible changes to regional weather patternsOther aspects of climate are also changing rainfall sea levelsnowglacier cover ocean phProxy record suggests the world is warm relative to the last6-800k years
Review
Atmospheric CO2 concentrations are very high relative to theirlevels over the past 6-800k years
measured CO2 has increased monotonically to 412 ppm atMauna Loa observatory (July 2019)ice core record suggests we are at or above atmospheric CO2concentrations observed over past 6-800k years
Review
Atmospheric CO2 almost certainly causes global warming andclimate change
The physics relating atmospheric CO2 to warming iselementary and uncontroversial Earthrsquos radiation spectrumconfirms the theoryThe ice core record confirms the theoretical relationshipbetween CO2 and climateAerosols are probably unprecedented as is the rate of increaseof atmospheric CO2 and mean that we should not expect thehistorical record to predict the path of future climateWe use climate models to make these guesses There is a lotof uncertainty
Review
We also introduced the BDICE model
maxIM
u(c1 c2) (1)
st W = c1 + I + M (2)
c2 = (1 + r)I minus γ(T2 minus T1)I (3)
E = (1 minus ρ4MW
)(ρ5(c1 + I)) (4)
P2 = ρ0E + P1 (5)
T2 = ρ1(P2 minus P1) + T1 (6)
Last time we talked about the red parts
The last equation is a climate model We discussed all of thepieces of this model last time our endowment of temperatureand atmospheric CO2 along with climate models relatingatmospheric CO2 to climate
Review
The next to last equation is a model of the atmosphericcarbon cycle We discussed our endowment and projectedatmospheric CO2 last time
This time we want to talk about Emissions E ρ0 therelationship between emissions and concentration and ρ5 therelationship between consumption and emissions
Carbon cycle
Emissions and concentration of CO2
What is the relationship between emissions and atmosphericconcentration
Each ppm of atmospheric concentration is about 212 Gt C This is a standard conversion factor both IPCC and Hansenuse it (gigatons = billion tons)A molecule of CO2 is about 4412 as heavy as a molecule ofC Thus each ppm of atmospheric concentration of C isabout 212GtC times (4412) = 777GtCO2Hansen and IPCC 20072013 Physical Science Basismeasure emissions in terms of Gt C but Stern IPCC20072013 Mitigation of Climate Change measure emissionsin terms of Gt CO2 Social scientists often measure Green house gases in termsof CO2 equivalent emissions
In July 2019 the concentration of CO2 in the atmosphere was 412ppm This is equal to 873 Gt C and 3201 Gt CO2
Carbon cycle
CO2 is not the only GHG I
From Stern 2008 table 81
Carbon cycle
CO2 is not the only GHG II
July 2019 concentration of CO2 was 412 ppm Using thenumbers above current CO2e is 412077 = 535CO2e
From the forcing tables we see that non-CO2 is has about halfthe forcing capacity of CO2 However non-CO2 is lesspersistent so it makes a smaller total contribution to warmingthan this share suggests
Carbon cycle
What is lsquoGlobal Warming Potentialrsquo I
We would like to calculate the rate at which we are willing totrade CH4 for CO2 To do this define αt as the change inradiative forcing from one unit of concentration of the gas at t
ieWm2
PPM Define GWP as warming potential relative to CO2
GWP(CH4 ) =
int T0 αCH4 (t)dtint T0 αCO2 (t)dt
Example suppose t = 1 2 3 and for CO2 (αCO2 (1) αCO2 (2) αCO2 (3)) = (1 1 1) and for CH4 (αCH4 (1) αCH4 (2) αCH4 (3)) = (2 0 0)Then GWP(CH4 ) = 2+0+0
1+1+1
Carbon cycle
What is lsquoGlobal Warming Potentialrsquo II
Issues
T is completely arbitrary GWP of CH4 for T = 20 100 500 isabout 63 21 9We care about damage not radiative forcing (see Schmalensee The
Energy Journal (1993)) To see this considerIf we anticipate that the world will end in 20 years then neitherCO2 nor CH4 is very harmful but CH4 causes a lot morewarming over that time than CO2If we plan to spend the next 20 years as we do now but then topermanently convert to an economy based on penguinfarming then CH4 emissions now are not very harmful but CO2is (because it is persistent)
We canrsquot really assign relative values to CO2 and CH4 until wesolve for the whole optimal path of emissions for both gasesso any definition of GWP is going to be unsatisfactory
Carbon cycle
Units
Stern 2007 p193 gives CO2e emissions for 2000 as 42Gt CO2e Hansen has 85 Gt C from fossil fuelCan we reconcile these numbers(Yes)
About 77 of CO2e is CO2
About 18 of CO2 is non fossil fuel (more on this later)
Stern reports CO2 Hansen C
so Sternrsquos 42 Gt CO2e becomes42 times (77(1 minus 18))times (1244) = 72 Gt of atmospheric C It would be closer but Stern uses 2000 numbers and Hansenrsquos 85is for about 2008
Atmospheric carbon cycle
Carbon cycle
Carbon is cycled back and forth between the atmosphere oceanand land by biological and chemical processes This means thatemissions donrsquot translate immediately into atmosphericconcentrations Stocksannual flows of C (not CO2 ) are
Atmosphere 800+45Gt
Ocean 40000+3Gt
Volcanos ndash-01Gt
Forests 600-16 Gt
Fossil fuels 5000-85
Sediments ndash-1Gt
Atmospheric carbon cycle
Fossil fuel emissions and deforestation put about 10Gt C in theatmosphere (ca 2007) Atmospheric C increased by about 45GtAbout 3Gt are absorbed by the ocean The remaining 25Gt arethought to be absorbed by plants (NB old numbers to go withfigure) Numbers from Hansen 2009 about the same as in Jacob 1999
Black = natural Red=Anthropogenic AOGCM models of carbon cycle are complicated IPCC 2007 Physical Science basis
figure 73
Atmospheric carbon cycle
Atmospheric CO2 cycle data I
Another way to see this is to look at the relationship betweenemissions and concentration directly
Calculate annual change in C ppm from Mauna Loa (eg)
Calculate annual emissions using emissions rates andconsumption data (more below)
Calculate ratio ∆CO2ppmFossil Fuel emissions = concentration yield of
emissions
Atmospheric carbon cycle
Atmospheric CO2 cycle data II
1950 1960 1970 1980 1990 2000 2010 0
2
4
6
8
10
Global Fossil Fuel CO2 EmissionsCO2 Airborne Fraction (7minusyear mean)
Em
issi
ons
(Gig
aton
s C
yea
r)
0
20
40
60
80
100
Air
born
e Fr
actio
n (
)
Hansen 2009 figure 16
Atmospheric carbon cycle
Atmospheric CO2 cycle data III
So concentration yield of emissions is about 55 Thus
(1055)= 18 Gt C emissions gives 1 Gt ton of atmospheric C
212 Gt atmospheric C to gives 1ppm atmospheric C (or CO2 )
Multiplying 18 times 212 = 38Gt C of emissions to get 1ppm ofatmospheric concentration
Recall the carbon cycle equation from our model
P2 = ρ0E + P1
We have just calculated that ρ0 = 138 = 026ppm C (or CO2 )
Gt C
What is ρ0 if we denominate emissions in terms of CO2
Atmospheric carbon cycle
Atmospheric CO2 cycle data IV
In Hansenrsquos graph the fraction of emissions retained in theatmosphere is CONSTANT as emissions are increasing This isthought to reflect increased absorbtion by plant lsquocarbonfertilizationrsquo or increased lsquonet primary productivityrsquo
In AOGCMrsquos the carbon cycle is modelled very carefully We reallywant to deal with the possibility that absorbtion varies withtemperature or CO2 (it probably does) and there is a lot ofuncertainty about this relationship
Consumption and emissions
Emissions for particular activities I
CO2 from gasoline 23 kgliter = 194 poundsgallon So1000 kg of CO2 emission results from 435 liters or 114gallons of gas (about 1 not burned is mostly N2O so CO2e ishigher)
CO2 from diesel 27 kgliter = 222 poundsgallon 1000 kg ofCO2 emission results from 370 liters or 97 gallons of dieselhttpwwwepagovotaqclimate420f05001htmcalculating
BBQ propane tank about 18 pounds propane = 24kg = 53 lbCO2 (NB Gasoline weighs 63 poundsgallon so 18 poundsof gas gives about 54 pounds CO2 Propane has morehydrogen per carbon atom than gasoline)
Consumption and emissions
Emissions for particular activities II
CO2 sequestration by 1 acre 90 year old pine forest inSoutheastern US is about 100 tons C about 1 tonacreyearSo burning this acre releases about 100 tons C or 367 tonsCO2 httpwwwepagovsequestrationfaqhtml For tropical forests about 18times as much not reliable source
CO2 from coal about 200 tons CO2 per ton (a lot of the stuffin coal is not burned ndash I think) or 2100lb CO2 per 1000 KWHfrom non-baseload coal burning electricity generation CO2eis higher Baseload will usually be lower (often nuclear orhydro) httpwwweiagovtoolsfaqsfaqcfmid=74ampt=11
Consumption and emissions
Emissions for particular activities III
For natural gas about 1200lb CO2 per 1000 KWH Sofracking is fantastic unless too much methane leaks beforeitrsquos burnt With 1 ton of methane worth 23 tons of CO2 about43 leakage makes coal and natural gas even (unless thereis methane leakage from coal mines) The rate of leakage iscurrently contested EPA current estimate is about 06 but05 is probably better (Allen et al PNAS 2013)
For reference Avg household in RI = 500KWHmo Avghousehold in TX = 1000KWHmohttpswwweiagovtoolsfaqsfaqcfmid=97ampt=3 (Feb 2016) Or averagehousehold in Providence sim 8000kwhyear in 2001 Dallas sim18500kwhyear (Glaeser and Kahn JUE 2010)
Consumption and emissions
Emissions for particular activities IV
For thinking about fracking also consider the following
Consumption and emissions
Global emissions per unit of consumption ca 2013
Using these sorts of particular numbers together with informationabout aggregate consumption one can calculate world emissions
Global annual emissions ca 2013 are about 49Gt CO2e or49 times 12
44 sim 133 Gt C (more on this later)
World GDP in 2013 is about 77 trillion USD (NB this is W inour model)
Dividingwe have 133times109 tons C77times1012000USD = 133
7700ton CUSD sim 017 kg C
USD (1 ton= 1000 kg) Multiply by 4412 for CO2 instead of C
Recall the third equation from our global warming model
E = (1 minus ρ4MW
)(ρ5(c1 + I)) (7)
Wersquove just calculated ρ5 Why is this sloppy
Consumption and emissions
Emissions per unit of consumption by countryItrsquos also interesting to look at the country by countrybreakdown(ca 2004) The US and Canada make a lot of stuffper ton of emissions
IPCC 2007 Mitigation fig SPM3b
What if China and Africa made same output at USCAemission rates This is why technology transfer is importantCompare 068 kg CO2e per dollar ca 2004 to my calculationof 017 kg C per dollar 2013 How important is technicalprogress
Consumption and emissions
Technological progress I
httpwww3epagovclimatechangescienceindicatorsghgus-ghg-emissionshtml January 2016
Consumption and emissions
Technological progress II
Nordhaus does this calculation every year country by country
Russia
India
World
EU
US
China
Consumption and emissions
Emissions - Summary
Wersquove now calculated ρ5 emissions per GDP at about 017kgC per dollar ca 2013Looking at the data a little more carefully highlights twodeficiencies on our model
Technological progress is at work so this ratio changes overtimeThere are huge difference across places in this ratio
This highlights the importance of technological progress andtechnology transfer in solving the problem of climate change
Wersquoll address this when we get to the Nordhaus model
Emissions
Emissions trends and levels
Recall
maxIM
u(c1 c2) (8)
st W = c1 + I + M (9)
c2 = (1 + r)I minus γ(T2 minus T1)I (10)
E = (1 minus ρ4MW
)(ρ5(c1 + I)) (11)
P2 = ρ0E + P1 (12)
T2 = ρ1(P2 minus P1) + T1 (13)
Wersquove filled in a bit more The next step is to look at E This meanslooking at trends and levels in CO2 emissions
Emissions
CO2e 1970-2010
IPCC 2013 WG3 fig TS1
Right panel gives confidence bounds for 2010 49Gt CO2e in 2010
Emissions
CO2 by purpose and country income 1750-2010
IPCC 2013 WG3 fig TS2
Emissions
Hansenrsquos version of the same thing
Flow StockHansen 2009 fig 27
Contributions to stock and flow are very different At thenegotiating table developing countries want the right to emit sinceeveryone else had their turn
Emissions
2010 CO2e by purpose
IPCC 2013 WG3 fig TS3
Emissions
2010 CO2e by purpose and country income
IPCC 2013 WG3 fig TS3
Emissions
US 1990-2017 CO2e
ES-4 Inventory of US Greenhouse Gas Emissions and Sinks 1990ndash2017
ES2 Recent Trends in US Greenhouse Gas Emissions and Sinks
In 2017 total gross US greenhouse gas emissions were 64567 MMT or million metric tons of carbon dioxide (CO2) Eq11 Total US emissions have increased by 13 percent from 1990 to 2017 and emissions decreased from 2016 to 2017 by 05 percent (355 MMT CO2 Eq) The decrease in total greenhouse gas emissions between 2016 and 2017 was driven in part by a decrease in CO2 emissions from fossil fuel combustion The decrease in CO2 emissions from fossil fuel combustion was a result of multiple factors including a continued shift from coal to natural gas and increased use of renewable energy in the electric power sector and milder weather that contributed to less overall electricity use
Relative to 1990 the baseline for this Inventory gross emissions in 2017 are higher by 13 percent down from a high of 157 percent above 1990 levels in 2007 Overall net emissions in 2017 were 130 percent below 2005 levels as shown in Table ES-2 Figure ES-1 through Figure ES-3 illustrate the overall trends in total US emissions by gas annual changes and absolute change since 1990 and Table ES-2 provides a detailed summary of gross US greenhouse gas emissions and sinks for 1990 through 2017 Note unless otherwise stated all tables and figures provide total gross emissions and exclude the greenhouse gas fluxes from the Land Use Land-Use Change and Forestry (LULUCF) sector (see Section ES3 Overview of Sector Emissions and Trends)
Figure ES-1 Gross US Greenhouse Gas Emissions by Gas (MMT CO2 Eq)
11 The gross emissions total presented in this report for the United States excludes emissions and removals from Land Use Land-Use Change and Forestry (LULUCF) The net emissions total presented in this report for the United States includes emissions and removals from LULUCF
httpswwwepagovsitesproductionfiles2019-04documentsus-ghg-inventory-2019-main-textpdf September 2019
This reflects fracking recession technical progress off-shoring ofmanufacturing Emissions are likely up since 2017
Emissions
Emissions per person
Itrsquos also interesting to look at the country by country breakdown interms of emissions per capita
IPCC 2007 Mitigation fig SPM3a
As of 2012 US had 454 tons C person and for India this numberwas 046 China was 18(httpcdiacornlgovtrendsemistop2011cap)
Emissions
The problem of stabilizing atmospheric CO2Emissions are about 13Gt C per year
The ocean and biosphere absorb about 45 of emissions (sofar)
This means the ocean and biosphere absorb 13 times 045 asymp 6GtC per year
As a rough guess this means that reducing emissions to 6GtC per year will stabilize atmospheric CO2 (but not climate)
This involves a 55 decrease For an average American thismeans this means reducing emissions from 45 tons per yearto about 20 if US share of total emissions stays constant Ifemissions are allocated equally to each of the worldrsquos 74bpeople then each of us gets 6Gt C 74b people or about 08ton This is an 82 decrease for the average American It isalso about the twice the level of the average Indian and halfthat of the average Chinese
Emissions
Summary
2013 emissions of CO2e were about 49Gt Of this 35Gt wasCO2 and of this about 30Gt from fossil fuels and 5Gt fromland use change and agriculture This is E in our model
Emission are growing rapidly about 2year between 2000and 2010 1970 CO2e was 30Gt
2010 CO2e 14 transport 18 buildings 21 industry 24AFOLU We could use this to calculate refinements of ρ5
The countries responsible for most of the stock are not thecountries responsible for most of the flow
Per capita emissions vary by a factor of about 10 between richand poor countries
There has been a decline in US emissions since 2008 due tofracking recession technical progress off shoring
Peak oil
Will we run out of fossil fuel INot soon enough to matter
0
200
400
600
800
Estimated Reserves
Emissions to Date
Gig
aton
s C
arbo
n
Oil Gas Coal Land Use
EIA
IPCCEIA
IPCC
100
200
300
Em
itted
CO
2 (p
pm)
0
200
400
600
800
We have oceans of coal and lots of oil and these figures predateUS fracking
Peak oil
Will we run out of fossil fuel II
Conclusion
Conclusion I
Here is where we stand with our model
maxIM
u(c1 c2) (14)
st W = c1 + I + M (15)
c2 = (1 + r)I minus γ(T2 minus T1)I (16)
E = (1 minus ρ4MW
)(ρ5(c1 + I)) (17)
P2 = ρ0E + P1 (18)
T2 = ρ1(P2 minus P1) + T1 (19)
We have enough pieces filled in to permit you to calculate theimpact on future climate of particular sorts of current consumptioneg burning a tank of propane on your bbq Wersquoll next start
Conclusion
Conclusion II
thinking about the effect of climate change on production γthough wersquoll make an aside to talk about measurement error first
Conclusion
Conclusion III
Each ppm of atmospheric CO2 corresponds to about 212 Gt C
and 778 Gt of CO2 Pay attention to the units people use
Not all gases are equal in their green house potential CO2 ismost common and most important but other gases are moreimportant per unit of emissions
Over the past 50 years about 55 of each emitted Gt of C
has stayed in the atmosphere The rest has been absorbed byland or oceans Thus it takes about 38 Gt C per 1ppm ofatmospheric CO2
Conclusion
Conclusion IV
Emissions are about 13Gt C for 2013 The rate at whichatmospheric CO2 is increasing has risen from about 1ppmyr1960s to 2ppm for 2000rsquos Since there is lots of fuel weshould expect atmospheric CO2 to continue to increase and atan increasing rate lsquobusiness as usual scenarios call foratmospheric CO2e gt 800 within 100 years
Not all countries are the same They are responsible fordifferent shares have different per capita emissions useemission more or less efficiently and are responsible fordifferent shares of historical emissions These factors are veryimportant obstacles to international agreements and alsosuggest the need for a richer model
Conclusion
Conclusion V
Steady state CO2 emissions are probably very small Sternsuggests less than 13 of current Our calculations suggest(1-055)=45
Outline
1 Review
2 Carbon cycle
3 Atmospheric carbon cycle
4 Consumption and emissions
5 Emissions
6 Peak oil
7 Conclusion
Review
Last time wedescribed our endowment of climate and atmospheric CO2 anddiscussed climate models that allow us to link current climate andCO2 to future climate
The world has warmed by about 1 degree Celsius sincepreindustrial times
This warming is not uniform Poles are warming fasterPossible changes to regional weather patternsOther aspects of climate are also changing rainfall sea levelsnowglacier cover ocean phProxy record suggests the world is warm relative to the last6-800k years
Review
Atmospheric CO2 concentrations are very high relative to theirlevels over the past 6-800k years
measured CO2 has increased monotonically to 412 ppm atMauna Loa observatory (July 2019)ice core record suggests we are at or above atmospheric CO2concentrations observed over past 6-800k years
Review
Atmospheric CO2 almost certainly causes global warming andclimate change
The physics relating atmospheric CO2 to warming iselementary and uncontroversial Earthrsquos radiation spectrumconfirms the theoryThe ice core record confirms the theoretical relationshipbetween CO2 and climateAerosols are probably unprecedented as is the rate of increaseof atmospheric CO2 and mean that we should not expect thehistorical record to predict the path of future climateWe use climate models to make these guesses There is a lotof uncertainty
Review
We also introduced the BDICE model
maxIM
u(c1 c2) (1)
st W = c1 + I + M (2)
c2 = (1 + r)I minus γ(T2 minus T1)I (3)
E = (1 minus ρ4MW
)(ρ5(c1 + I)) (4)
P2 = ρ0E + P1 (5)
T2 = ρ1(P2 minus P1) + T1 (6)
Last time we talked about the red parts
The last equation is a climate model We discussed all of thepieces of this model last time our endowment of temperatureand atmospheric CO2 along with climate models relatingatmospheric CO2 to climate
Review
The next to last equation is a model of the atmosphericcarbon cycle We discussed our endowment and projectedatmospheric CO2 last time
This time we want to talk about Emissions E ρ0 therelationship between emissions and concentration and ρ5 therelationship between consumption and emissions
Carbon cycle
Emissions and concentration of CO2
What is the relationship between emissions and atmosphericconcentration
Each ppm of atmospheric concentration is about 212 Gt C This is a standard conversion factor both IPCC and Hansenuse it (gigatons = billion tons)A molecule of CO2 is about 4412 as heavy as a molecule ofC Thus each ppm of atmospheric concentration of C isabout 212GtC times (4412) = 777GtCO2Hansen and IPCC 20072013 Physical Science Basismeasure emissions in terms of Gt C but Stern IPCC20072013 Mitigation of Climate Change measure emissionsin terms of Gt CO2 Social scientists often measure Green house gases in termsof CO2 equivalent emissions
In July 2019 the concentration of CO2 in the atmosphere was 412ppm This is equal to 873 Gt C and 3201 Gt CO2
Carbon cycle
CO2 is not the only GHG I
From Stern 2008 table 81
Carbon cycle
CO2 is not the only GHG II
July 2019 concentration of CO2 was 412 ppm Using thenumbers above current CO2e is 412077 = 535CO2e
From the forcing tables we see that non-CO2 is has about halfthe forcing capacity of CO2 However non-CO2 is lesspersistent so it makes a smaller total contribution to warmingthan this share suggests
Carbon cycle
What is lsquoGlobal Warming Potentialrsquo I
We would like to calculate the rate at which we are willing totrade CH4 for CO2 To do this define αt as the change inradiative forcing from one unit of concentration of the gas at t
ieWm2
PPM Define GWP as warming potential relative to CO2
GWP(CH4 ) =
int T0 αCH4 (t)dtint T0 αCO2 (t)dt
Example suppose t = 1 2 3 and for CO2 (αCO2 (1) αCO2 (2) αCO2 (3)) = (1 1 1) and for CH4 (αCH4 (1) αCH4 (2) αCH4 (3)) = (2 0 0)Then GWP(CH4 ) = 2+0+0
1+1+1
Carbon cycle
What is lsquoGlobal Warming Potentialrsquo II
Issues
T is completely arbitrary GWP of CH4 for T = 20 100 500 isabout 63 21 9We care about damage not radiative forcing (see Schmalensee The
Energy Journal (1993)) To see this considerIf we anticipate that the world will end in 20 years then neitherCO2 nor CH4 is very harmful but CH4 causes a lot morewarming over that time than CO2If we plan to spend the next 20 years as we do now but then topermanently convert to an economy based on penguinfarming then CH4 emissions now are not very harmful but CO2is (because it is persistent)
We canrsquot really assign relative values to CO2 and CH4 until wesolve for the whole optimal path of emissions for both gasesso any definition of GWP is going to be unsatisfactory
Carbon cycle
Units
Stern 2007 p193 gives CO2e emissions for 2000 as 42Gt CO2e Hansen has 85 Gt C from fossil fuelCan we reconcile these numbers(Yes)
About 77 of CO2e is CO2
About 18 of CO2 is non fossil fuel (more on this later)
Stern reports CO2 Hansen C
so Sternrsquos 42 Gt CO2e becomes42 times (77(1 minus 18))times (1244) = 72 Gt of atmospheric C It would be closer but Stern uses 2000 numbers and Hansenrsquos 85is for about 2008
Atmospheric carbon cycle
Carbon cycle
Carbon is cycled back and forth between the atmosphere oceanand land by biological and chemical processes This means thatemissions donrsquot translate immediately into atmosphericconcentrations Stocksannual flows of C (not CO2 ) are
Atmosphere 800+45Gt
Ocean 40000+3Gt
Volcanos ndash-01Gt
Forests 600-16 Gt
Fossil fuels 5000-85
Sediments ndash-1Gt
Atmospheric carbon cycle
Fossil fuel emissions and deforestation put about 10Gt C in theatmosphere (ca 2007) Atmospheric C increased by about 45GtAbout 3Gt are absorbed by the ocean The remaining 25Gt arethought to be absorbed by plants (NB old numbers to go withfigure) Numbers from Hansen 2009 about the same as in Jacob 1999
Black = natural Red=Anthropogenic AOGCM models of carbon cycle are complicated IPCC 2007 Physical Science basis
figure 73
Atmospheric carbon cycle
Atmospheric CO2 cycle data I
Another way to see this is to look at the relationship betweenemissions and concentration directly
Calculate annual change in C ppm from Mauna Loa (eg)
Calculate annual emissions using emissions rates andconsumption data (more below)
Calculate ratio ∆CO2ppmFossil Fuel emissions = concentration yield of
emissions
Atmospheric carbon cycle
Atmospheric CO2 cycle data II
1950 1960 1970 1980 1990 2000 2010 0
2
4
6
8
10
Global Fossil Fuel CO2 EmissionsCO2 Airborne Fraction (7minusyear mean)
Em
issi
ons
(Gig
aton
s C
yea
r)
0
20
40
60
80
100
Air
born
e Fr
actio
n (
)
Hansen 2009 figure 16
Atmospheric carbon cycle
Atmospheric CO2 cycle data III
So concentration yield of emissions is about 55 Thus
(1055)= 18 Gt C emissions gives 1 Gt ton of atmospheric C
212 Gt atmospheric C to gives 1ppm atmospheric C (or CO2 )
Multiplying 18 times 212 = 38Gt C of emissions to get 1ppm ofatmospheric concentration
Recall the carbon cycle equation from our model
P2 = ρ0E + P1
We have just calculated that ρ0 = 138 = 026ppm C (or CO2 )
Gt C
What is ρ0 if we denominate emissions in terms of CO2
Atmospheric carbon cycle
Atmospheric CO2 cycle data IV
In Hansenrsquos graph the fraction of emissions retained in theatmosphere is CONSTANT as emissions are increasing This isthought to reflect increased absorbtion by plant lsquocarbonfertilizationrsquo or increased lsquonet primary productivityrsquo
In AOGCMrsquos the carbon cycle is modelled very carefully We reallywant to deal with the possibility that absorbtion varies withtemperature or CO2 (it probably does) and there is a lot ofuncertainty about this relationship
Consumption and emissions
Emissions for particular activities I
CO2 from gasoline 23 kgliter = 194 poundsgallon So1000 kg of CO2 emission results from 435 liters or 114gallons of gas (about 1 not burned is mostly N2O so CO2e ishigher)
CO2 from diesel 27 kgliter = 222 poundsgallon 1000 kg ofCO2 emission results from 370 liters or 97 gallons of dieselhttpwwwepagovotaqclimate420f05001htmcalculating
BBQ propane tank about 18 pounds propane = 24kg = 53 lbCO2 (NB Gasoline weighs 63 poundsgallon so 18 poundsof gas gives about 54 pounds CO2 Propane has morehydrogen per carbon atom than gasoline)
Consumption and emissions
Emissions for particular activities II
CO2 sequestration by 1 acre 90 year old pine forest inSoutheastern US is about 100 tons C about 1 tonacreyearSo burning this acre releases about 100 tons C or 367 tonsCO2 httpwwwepagovsequestrationfaqhtml For tropical forests about 18times as much not reliable source
CO2 from coal about 200 tons CO2 per ton (a lot of the stuffin coal is not burned ndash I think) or 2100lb CO2 per 1000 KWHfrom non-baseload coal burning electricity generation CO2eis higher Baseload will usually be lower (often nuclear orhydro) httpwwweiagovtoolsfaqsfaqcfmid=74ampt=11
Consumption and emissions
Emissions for particular activities III
For natural gas about 1200lb CO2 per 1000 KWH Sofracking is fantastic unless too much methane leaks beforeitrsquos burnt With 1 ton of methane worth 23 tons of CO2 about43 leakage makes coal and natural gas even (unless thereis methane leakage from coal mines) The rate of leakage iscurrently contested EPA current estimate is about 06 but05 is probably better (Allen et al PNAS 2013)
For reference Avg household in RI = 500KWHmo Avghousehold in TX = 1000KWHmohttpswwweiagovtoolsfaqsfaqcfmid=97ampt=3 (Feb 2016) Or averagehousehold in Providence sim 8000kwhyear in 2001 Dallas sim18500kwhyear (Glaeser and Kahn JUE 2010)
Consumption and emissions
Emissions for particular activities IV
For thinking about fracking also consider the following
Consumption and emissions
Global emissions per unit of consumption ca 2013
Using these sorts of particular numbers together with informationabout aggregate consumption one can calculate world emissions
Global annual emissions ca 2013 are about 49Gt CO2e or49 times 12
44 sim 133 Gt C (more on this later)
World GDP in 2013 is about 77 trillion USD (NB this is W inour model)
Dividingwe have 133times109 tons C77times1012000USD = 133
7700ton CUSD sim 017 kg C
USD (1 ton= 1000 kg) Multiply by 4412 for CO2 instead of C
Recall the third equation from our global warming model
E = (1 minus ρ4MW
)(ρ5(c1 + I)) (7)
Wersquove just calculated ρ5 Why is this sloppy
Consumption and emissions
Emissions per unit of consumption by countryItrsquos also interesting to look at the country by countrybreakdown(ca 2004) The US and Canada make a lot of stuffper ton of emissions
IPCC 2007 Mitigation fig SPM3b
What if China and Africa made same output at USCAemission rates This is why technology transfer is importantCompare 068 kg CO2e per dollar ca 2004 to my calculationof 017 kg C per dollar 2013 How important is technicalprogress
Consumption and emissions
Technological progress I
httpwww3epagovclimatechangescienceindicatorsghgus-ghg-emissionshtml January 2016
Consumption and emissions
Technological progress II
Nordhaus does this calculation every year country by country
Russia
India
World
EU
US
China
Consumption and emissions
Emissions - Summary
Wersquove now calculated ρ5 emissions per GDP at about 017kgC per dollar ca 2013Looking at the data a little more carefully highlights twodeficiencies on our model
Technological progress is at work so this ratio changes overtimeThere are huge difference across places in this ratio
This highlights the importance of technological progress andtechnology transfer in solving the problem of climate change
Wersquoll address this when we get to the Nordhaus model
Emissions
Emissions trends and levels
Recall
maxIM
u(c1 c2) (8)
st W = c1 + I + M (9)
c2 = (1 + r)I minus γ(T2 minus T1)I (10)
E = (1 minus ρ4MW
)(ρ5(c1 + I)) (11)
P2 = ρ0E + P1 (12)
T2 = ρ1(P2 minus P1) + T1 (13)
Wersquove filled in a bit more The next step is to look at E This meanslooking at trends and levels in CO2 emissions
Emissions
CO2e 1970-2010
IPCC 2013 WG3 fig TS1
Right panel gives confidence bounds for 2010 49Gt CO2e in 2010
Emissions
CO2 by purpose and country income 1750-2010
IPCC 2013 WG3 fig TS2
Emissions
Hansenrsquos version of the same thing
Flow StockHansen 2009 fig 27
Contributions to stock and flow are very different At thenegotiating table developing countries want the right to emit sinceeveryone else had their turn
Emissions
2010 CO2e by purpose
IPCC 2013 WG3 fig TS3
Emissions
2010 CO2e by purpose and country income
IPCC 2013 WG3 fig TS3
Emissions
US 1990-2017 CO2e
ES-4 Inventory of US Greenhouse Gas Emissions and Sinks 1990ndash2017
ES2 Recent Trends in US Greenhouse Gas Emissions and Sinks
In 2017 total gross US greenhouse gas emissions were 64567 MMT or million metric tons of carbon dioxide (CO2) Eq11 Total US emissions have increased by 13 percent from 1990 to 2017 and emissions decreased from 2016 to 2017 by 05 percent (355 MMT CO2 Eq) The decrease in total greenhouse gas emissions between 2016 and 2017 was driven in part by a decrease in CO2 emissions from fossil fuel combustion The decrease in CO2 emissions from fossil fuel combustion was a result of multiple factors including a continued shift from coal to natural gas and increased use of renewable energy in the electric power sector and milder weather that contributed to less overall electricity use
Relative to 1990 the baseline for this Inventory gross emissions in 2017 are higher by 13 percent down from a high of 157 percent above 1990 levels in 2007 Overall net emissions in 2017 were 130 percent below 2005 levels as shown in Table ES-2 Figure ES-1 through Figure ES-3 illustrate the overall trends in total US emissions by gas annual changes and absolute change since 1990 and Table ES-2 provides a detailed summary of gross US greenhouse gas emissions and sinks for 1990 through 2017 Note unless otherwise stated all tables and figures provide total gross emissions and exclude the greenhouse gas fluxes from the Land Use Land-Use Change and Forestry (LULUCF) sector (see Section ES3 Overview of Sector Emissions and Trends)
Figure ES-1 Gross US Greenhouse Gas Emissions by Gas (MMT CO2 Eq)
11 The gross emissions total presented in this report for the United States excludes emissions and removals from Land Use Land-Use Change and Forestry (LULUCF) The net emissions total presented in this report for the United States includes emissions and removals from LULUCF
httpswwwepagovsitesproductionfiles2019-04documentsus-ghg-inventory-2019-main-textpdf September 2019
This reflects fracking recession technical progress off-shoring ofmanufacturing Emissions are likely up since 2017
Emissions
Emissions per person
Itrsquos also interesting to look at the country by country breakdown interms of emissions per capita
IPCC 2007 Mitigation fig SPM3a
As of 2012 US had 454 tons C person and for India this numberwas 046 China was 18(httpcdiacornlgovtrendsemistop2011cap)
Emissions
The problem of stabilizing atmospheric CO2Emissions are about 13Gt C per year
The ocean and biosphere absorb about 45 of emissions (sofar)
This means the ocean and biosphere absorb 13 times 045 asymp 6GtC per year
As a rough guess this means that reducing emissions to 6GtC per year will stabilize atmospheric CO2 (but not climate)
This involves a 55 decrease For an average American thismeans this means reducing emissions from 45 tons per yearto about 20 if US share of total emissions stays constant Ifemissions are allocated equally to each of the worldrsquos 74bpeople then each of us gets 6Gt C 74b people or about 08ton This is an 82 decrease for the average American It isalso about the twice the level of the average Indian and halfthat of the average Chinese
Emissions
Summary
2013 emissions of CO2e were about 49Gt Of this 35Gt wasCO2 and of this about 30Gt from fossil fuels and 5Gt fromland use change and agriculture This is E in our model
Emission are growing rapidly about 2year between 2000and 2010 1970 CO2e was 30Gt
2010 CO2e 14 transport 18 buildings 21 industry 24AFOLU We could use this to calculate refinements of ρ5
The countries responsible for most of the stock are not thecountries responsible for most of the flow
Per capita emissions vary by a factor of about 10 between richand poor countries
There has been a decline in US emissions since 2008 due tofracking recession technical progress off shoring
Peak oil
Will we run out of fossil fuel INot soon enough to matter
0
200
400
600
800
Estimated Reserves
Emissions to Date
Gig
aton
s C
arbo
n
Oil Gas Coal Land Use
EIA
IPCCEIA
IPCC
100
200
300
Em
itted
CO
2 (p
pm)
0
200
400
600
800
We have oceans of coal and lots of oil and these figures predateUS fracking
Peak oil
Will we run out of fossil fuel II
Conclusion
Conclusion I
Here is where we stand with our model
maxIM
u(c1 c2) (14)
st W = c1 + I + M (15)
c2 = (1 + r)I minus γ(T2 minus T1)I (16)
E = (1 minus ρ4MW
)(ρ5(c1 + I)) (17)
P2 = ρ0E + P1 (18)
T2 = ρ1(P2 minus P1) + T1 (19)
We have enough pieces filled in to permit you to calculate theimpact on future climate of particular sorts of current consumptioneg burning a tank of propane on your bbq Wersquoll next start
Conclusion
Conclusion II
thinking about the effect of climate change on production γthough wersquoll make an aside to talk about measurement error first
Conclusion
Conclusion III
Each ppm of atmospheric CO2 corresponds to about 212 Gt C
and 778 Gt of CO2 Pay attention to the units people use
Not all gases are equal in their green house potential CO2 ismost common and most important but other gases are moreimportant per unit of emissions
Over the past 50 years about 55 of each emitted Gt of C
has stayed in the atmosphere The rest has been absorbed byland or oceans Thus it takes about 38 Gt C per 1ppm ofatmospheric CO2
Conclusion
Conclusion IV
Emissions are about 13Gt C for 2013 The rate at whichatmospheric CO2 is increasing has risen from about 1ppmyr1960s to 2ppm for 2000rsquos Since there is lots of fuel weshould expect atmospheric CO2 to continue to increase and atan increasing rate lsquobusiness as usual scenarios call foratmospheric CO2e gt 800 within 100 years
Not all countries are the same They are responsible fordifferent shares have different per capita emissions useemission more or less efficiently and are responsible fordifferent shares of historical emissions These factors are veryimportant obstacles to international agreements and alsosuggest the need for a richer model
Conclusion
Conclusion V
Steady state CO2 emissions are probably very small Sternsuggests less than 13 of current Our calculations suggest(1-055)=45
Review
Last time wedescribed our endowment of climate and atmospheric CO2 anddiscussed climate models that allow us to link current climate andCO2 to future climate
The world has warmed by about 1 degree Celsius sincepreindustrial times
This warming is not uniform Poles are warming fasterPossible changes to regional weather patternsOther aspects of climate are also changing rainfall sea levelsnowglacier cover ocean phProxy record suggests the world is warm relative to the last6-800k years
Review
Atmospheric CO2 concentrations are very high relative to theirlevels over the past 6-800k years
measured CO2 has increased monotonically to 412 ppm atMauna Loa observatory (July 2019)ice core record suggests we are at or above atmospheric CO2concentrations observed over past 6-800k years
Review
Atmospheric CO2 almost certainly causes global warming andclimate change
The physics relating atmospheric CO2 to warming iselementary and uncontroversial Earthrsquos radiation spectrumconfirms the theoryThe ice core record confirms the theoretical relationshipbetween CO2 and climateAerosols are probably unprecedented as is the rate of increaseof atmospheric CO2 and mean that we should not expect thehistorical record to predict the path of future climateWe use climate models to make these guesses There is a lotof uncertainty
Review
We also introduced the BDICE model
maxIM
u(c1 c2) (1)
st W = c1 + I + M (2)
c2 = (1 + r)I minus γ(T2 minus T1)I (3)
E = (1 minus ρ4MW
)(ρ5(c1 + I)) (4)
P2 = ρ0E + P1 (5)
T2 = ρ1(P2 minus P1) + T1 (6)
Last time we talked about the red parts
The last equation is a climate model We discussed all of thepieces of this model last time our endowment of temperatureand atmospheric CO2 along with climate models relatingatmospheric CO2 to climate
Review
The next to last equation is a model of the atmosphericcarbon cycle We discussed our endowment and projectedatmospheric CO2 last time
This time we want to talk about Emissions E ρ0 therelationship between emissions and concentration and ρ5 therelationship between consumption and emissions
Carbon cycle
Emissions and concentration of CO2
What is the relationship between emissions and atmosphericconcentration
Each ppm of atmospheric concentration is about 212 Gt C This is a standard conversion factor both IPCC and Hansenuse it (gigatons = billion tons)A molecule of CO2 is about 4412 as heavy as a molecule ofC Thus each ppm of atmospheric concentration of C isabout 212GtC times (4412) = 777GtCO2Hansen and IPCC 20072013 Physical Science Basismeasure emissions in terms of Gt C but Stern IPCC20072013 Mitigation of Climate Change measure emissionsin terms of Gt CO2 Social scientists often measure Green house gases in termsof CO2 equivalent emissions
In July 2019 the concentration of CO2 in the atmosphere was 412ppm This is equal to 873 Gt C and 3201 Gt CO2
Carbon cycle
CO2 is not the only GHG I
From Stern 2008 table 81
Carbon cycle
CO2 is not the only GHG II
July 2019 concentration of CO2 was 412 ppm Using thenumbers above current CO2e is 412077 = 535CO2e
From the forcing tables we see that non-CO2 is has about halfthe forcing capacity of CO2 However non-CO2 is lesspersistent so it makes a smaller total contribution to warmingthan this share suggests
Carbon cycle
What is lsquoGlobal Warming Potentialrsquo I
We would like to calculate the rate at which we are willing totrade CH4 for CO2 To do this define αt as the change inradiative forcing from one unit of concentration of the gas at t
ieWm2
PPM Define GWP as warming potential relative to CO2
GWP(CH4 ) =
int T0 αCH4 (t)dtint T0 αCO2 (t)dt
Example suppose t = 1 2 3 and for CO2 (αCO2 (1) αCO2 (2) αCO2 (3)) = (1 1 1) and for CH4 (αCH4 (1) αCH4 (2) αCH4 (3)) = (2 0 0)Then GWP(CH4 ) = 2+0+0
1+1+1
Carbon cycle
What is lsquoGlobal Warming Potentialrsquo II
Issues
T is completely arbitrary GWP of CH4 for T = 20 100 500 isabout 63 21 9We care about damage not radiative forcing (see Schmalensee The
Energy Journal (1993)) To see this considerIf we anticipate that the world will end in 20 years then neitherCO2 nor CH4 is very harmful but CH4 causes a lot morewarming over that time than CO2If we plan to spend the next 20 years as we do now but then topermanently convert to an economy based on penguinfarming then CH4 emissions now are not very harmful but CO2is (because it is persistent)
We canrsquot really assign relative values to CO2 and CH4 until wesolve for the whole optimal path of emissions for both gasesso any definition of GWP is going to be unsatisfactory
Carbon cycle
Units
Stern 2007 p193 gives CO2e emissions for 2000 as 42Gt CO2e Hansen has 85 Gt C from fossil fuelCan we reconcile these numbers(Yes)
About 77 of CO2e is CO2
About 18 of CO2 is non fossil fuel (more on this later)
Stern reports CO2 Hansen C
so Sternrsquos 42 Gt CO2e becomes42 times (77(1 minus 18))times (1244) = 72 Gt of atmospheric C It would be closer but Stern uses 2000 numbers and Hansenrsquos 85is for about 2008
Atmospheric carbon cycle
Carbon cycle
Carbon is cycled back and forth between the atmosphere oceanand land by biological and chemical processes This means thatemissions donrsquot translate immediately into atmosphericconcentrations Stocksannual flows of C (not CO2 ) are
Atmosphere 800+45Gt
Ocean 40000+3Gt
Volcanos ndash-01Gt
Forests 600-16 Gt
Fossil fuels 5000-85
Sediments ndash-1Gt
Atmospheric carbon cycle
Fossil fuel emissions and deforestation put about 10Gt C in theatmosphere (ca 2007) Atmospheric C increased by about 45GtAbout 3Gt are absorbed by the ocean The remaining 25Gt arethought to be absorbed by plants (NB old numbers to go withfigure) Numbers from Hansen 2009 about the same as in Jacob 1999
Black = natural Red=Anthropogenic AOGCM models of carbon cycle are complicated IPCC 2007 Physical Science basis
figure 73
Atmospheric carbon cycle
Atmospheric CO2 cycle data I
Another way to see this is to look at the relationship betweenemissions and concentration directly
Calculate annual change in C ppm from Mauna Loa (eg)
Calculate annual emissions using emissions rates andconsumption data (more below)
Calculate ratio ∆CO2ppmFossil Fuel emissions = concentration yield of
emissions
Atmospheric carbon cycle
Atmospheric CO2 cycle data II
1950 1960 1970 1980 1990 2000 2010 0
2
4
6
8
10
Global Fossil Fuel CO2 EmissionsCO2 Airborne Fraction (7minusyear mean)
Em
issi
ons
(Gig
aton
s C
yea
r)
0
20
40
60
80
100
Air
born
e Fr
actio
n (
)
Hansen 2009 figure 16
Atmospheric carbon cycle
Atmospheric CO2 cycle data III
So concentration yield of emissions is about 55 Thus
(1055)= 18 Gt C emissions gives 1 Gt ton of atmospheric C
212 Gt atmospheric C to gives 1ppm atmospheric C (or CO2 )
Multiplying 18 times 212 = 38Gt C of emissions to get 1ppm ofatmospheric concentration
Recall the carbon cycle equation from our model
P2 = ρ0E + P1
We have just calculated that ρ0 = 138 = 026ppm C (or CO2 )
Gt C
What is ρ0 if we denominate emissions in terms of CO2
Atmospheric carbon cycle
Atmospheric CO2 cycle data IV
In Hansenrsquos graph the fraction of emissions retained in theatmosphere is CONSTANT as emissions are increasing This isthought to reflect increased absorbtion by plant lsquocarbonfertilizationrsquo or increased lsquonet primary productivityrsquo
In AOGCMrsquos the carbon cycle is modelled very carefully We reallywant to deal with the possibility that absorbtion varies withtemperature or CO2 (it probably does) and there is a lot ofuncertainty about this relationship
Consumption and emissions
Emissions for particular activities I
CO2 from gasoline 23 kgliter = 194 poundsgallon So1000 kg of CO2 emission results from 435 liters or 114gallons of gas (about 1 not burned is mostly N2O so CO2e ishigher)
CO2 from diesel 27 kgliter = 222 poundsgallon 1000 kg ofCO2 emission results from 370 liters or 97 gallons of dieselhttpwwwepagovotaqclimate420f05001htmcalculating
BBQ propane tank about 18 pounds propane = 24kg = 53 lbCO2 (NB Gasoline weighs 63 poundsgallon so 18 poundsof gas gives about 54 pounds CO2 Propane has morehydrogen per carbon atom than gasoline)
Consumption and emissions
Emissions for particular activities II
CO2 sequestration by 1 acre 90 year old pine forest inSoutheastern US is about 100 tons C about 1 tonacreyearSo burning this acre releases about 100 tons C or 367 tonsCO2 httpwwwepagovsequestrationfaqhtml For tropical forests about 18times as much not reliable source
CO2 from coal about 200 tons CO2 per ton (a lot of the stuffin coal is not burned ndash I think) or 2100lb CO2 per 1000 KWHfrom non-baseload coal burning electricity generation CO2eis higher Baseload will usually be lower (often nuclear orhydro) httpwwweiagovtoolsfaqsfaqcfmid=74ampt=11
Consumption and emissions
Emissions for particular activities III
For natural gas about 1200lb CO2 per 1000 KWH Sofracking is fantastic unless too much methane leaks beforeitrsquos burnt With 1 ton of methane worth 23 tons of CO2 about43 leakage makes coal and natural gas even (unless thereis methane leakage from coal mines) The rate of leakage iscurrently contested EPA current estimate is about 06 but05 is probably better (Allen et al PNAS 2013)
For reference Avg household in RI = 500KWHmo Avghousehold in TX = 1000KWHmohttpswwweiagovtoolsfaqsfaqcfmid=97ampt=3 (Feb 2016) Or averagehousehold in Providence sim 8000kwhyear in 2001 Dallas sim18500kwhyear (Glaeser and Kahn JUE 2010)
Consumption and emissions
Emissions for particular activities IV
For thinking about fracking also consider the following
Consumption and emissions
Global emissions per unit of consumption ca 2013
Using these sorts of particular numbers together with informationabout aggregate consumption one can calculate world emissions
Global annual emissions ca 2013 are about 49Gt CO2e or49 times 12
44 sim 133 Gt C (more on this later)
World GDP in 2013 is about 77 trillion USD (NB this is W inour model)
Dividingwe have 133times109 tons C77times1012000USD = 133
7700ton CUSD sim 017 kg C
USD (1 ton= 1000 kg) Multiply by 4412 for CO2 instead of C
Recall the third equation from our global warming model
E = (1 minus ρ4MW
)(ρ5(c1 + I)) (7)
Wersquove just calculated ρ5 Why is this sloppy
Consumption and emissions
Emissions per unit of consumption by countryItrsquos also interesting to look at the country by countrybreakdown(ca 2004) The US and Canada make a lot of stuffper ton of emissions
IPCC 2007 Mitigation fig SPM3b
What if China and Africa made same output at USCAemission rates This is why technology transfer is importantCompare 068 kg CO2e per dollar ca 2004 to my calculationof 017 kg C per dollar 2013 How important is technicalprogress
Consumption and emissions
Technological progress I
httpwww3epagovclimatechangescienceindicatorsghgus-ghg-emissionshtml January 2016
Consumption and emissions
Technological progress II
Nordhaus does this calculation every year country by country
Russia
India
World
EU
US
China
Consumption and emissions
Emissions - Summary
Wersquove now calculated ρ5 emissions per GDP at about 017kgC per dollar ca 2013Looking at the data a little more carefully highlights twodeficiencies on our model
Technological progress is at work so this ratio changes overtimeThere are huge difference across places in this ratio
This highlights the importance of technological progress andtechnology transfer in solving the problem of climate change
Wersquoll address this when we get to the Nordhaus model
Emissions
Emissions trends and levels
Recall
maxIM
u(c1 c2) (8)
st W = c1 + I + M (9)
c2 = (1 + r)I minus γ(T2 minus T1)I (10)
E = (1 minus ρ4MW
)(ρ5(c1 + I)) (11)
P2 = ρ0E + P1 (12)
T2 = ρ1(P2 minus P1) + T1 (13)
Wersquove filled in a bit more The next step is to look at E This meanslooking at trends and levels in CO2 emissions
Emissions
CO2e 1970-2010
IPCC 2013 WG3 fig TS1
Right panel gives confidence bounds for 2010 49Gt CO2e in 2010
Emissions
CO2 by purpose and country income 1750-2010
IPCC 2013 WG3 fig TS2
Emissions
Hansenrsquos version of the same thing
Flow StockHansen 2009 fig 27
Contributions to stock and flow are very different At thenegotiating table developing countries want the right to emit sinceeveryone else had their turn
Emissions
2010 CO2e by purpose
IPCC 2013 WG3 fig TS3
Emissions
2010 CO2e by purpose and country income
IPCC 2013 WG3 fig TS3
Emissions
US 1990-2017 CO2e
ES-4 Inventory of US Greenhouse Gas Emissions and Sinks 1990ndash2017
ES2 Recent Trends in US Greenhouse Gas Emissions and Sinks
In 2017 total gross US greenhouse gas emissions were 64567 MMT or million metric tons of carbon dioxide (CO2) Eq11 Total US emissions have increased by 13 percent from 1990 to 2017 and emissions decreased from 2016 to 2017 by 05 percent (355 MMT CO2 Eq) The decrease in total greenhouse gas emissions between 2016 and 2017 was driven in part by a decrease in CO2 emissions from fossil fuel combustion The decrease in CO2 emissions from fossil fuel combustion was a result of multiple factors including a continued shift from coal to natural gas and increased use of renewable energy in the electric power sector and milder weather that contributed to less overall electricity use
Relative to 1990 the baseline for this Inventory gross emissions in 2017 are higher by 13 percent down from a high of 157 percent above 1990 levels in 2007 Overall net emissions in 2017 were 130 percent below 2005 levels as shown in Table ES-2 Figure ES-1 through Figure ES-3 illustrate the overall trends in total US emissions by gas annual changes and absolute change since 1990 and Table ES-2 provides a detailed summary of gross US greenhouse gas emissions and sinks for 1990 through 2017 Note unless otherwise stated all tables and figures provide total gross emissions and exclude the greenhouse gas fluxes from the Land Use Land-Use Change and Forestry (LULUCF) sector (see Section ES3 Overview of Sector Emissions and Trends)
Figure ES-1 Gross US Greenhouse Gas Emissions by Gas (MMT CO2 Eq)
11 The gross emissions total presented in this report for the United States excludes emissions and removals from Land Use Land-Use Change and Forestry (LULUCF) The net emissions total presented in this report for the United States includes emissions and removals from LULUCF
httpswwwepagovsitesproductionfiles2019-04documentsus-ghg-inventory-2019-main-textpdf September 2019
This reflects fracking recession technical progress off-shoring ofmanufacturing Emissions are likely up since 2017
Emissions
Emissions per person
Itrsquos also interesting to look at the country by country breakdown interms of emissions per capita
IPCC 2007 Mitigation fig SPM3a
As of 2012 US had 454 tons C person and for India this numberwas 046 China was 18(httpcdiacornlgovtrendsemistop2011cap)
Emissions
The problem of stabilizing atmospheric CO2Emissions are about 13Gt C per year
The ocean and biosphere absorb about 45 of emissions (sofar)
This means the ocean and biosphere absorb 13 times 045 asymp 6GtC per year
As a rough guess this means that reducing emissions to 6GtC per year will stabilize atmospheric CO2 (but not climate)
This involves a 55 decrease For an average American thismeans this means reducing emissions from 45 tons per yearto about 20 if US share of total emissions stays constant Ifemissions are allocated equally to each of the worldrsquos 74bpeople then each of us gets 6Gt C 74b people or about 08ton This is an 82 decrease for the average American It isalso about the twice the level of the average Indian and halfthat of the average Chinese
Emissions
Summary
2013 emissions of CO2e were about 49Gt Of this 35Gt wasCO2 and of this about 30Gt from fossil fuels and 5Gt fromland use change and agriculture This is E in our model
Emission are growing rapidly about 2year between 2000and 2010 1970 CO2e was 30Gt
2010 CO2e 14 transport 18 buildings 21 industry 24AFOLU We could use this to calculate refinements of ρ5
The countries responsible for most of the stock are not thecountries responsible for most of the flow
Per capita emissions vary by a factor of about 10 between richand poor countries
There has been a decline in US emissions since 2008 due tofracking recession technical progress off shoring
Peak oil
Will we run out of fossil fuel INot soon enough to matter
0
200
400
600
800
Estimated Reserves
Emissions to Date
Gig
aton
s C
arbo
n
Oil Gas Coal Land Use
EIA
IPCCEIA
IPCC
100
200
300
Em
itted
CO
2 (p
pm)
0
200
400
600
800
We have oceans of coal and lots of oil and these figures predateUS fracking
Peak oil
Will we run out of fossil fuel II
Conclusion
Conclusion I
Here is where we stand with our model
maxIM
u(c1 c2) (14)
st W = c1 + I + M (15)
c2 = (1 + r)I minus γ(T2 minus T1)I (16)
E = (1 minus ρ4MW
)(ρ5(c1 + I)) (17)
P2 = ρ0E + P1 (18)
T2 = ρ1(P2 minus P1) + T1 (19)
We have enough pieces filled in to permit you to calculate theimpact on future climate of particular sorts of current consumptioneg burning a tank of propane on your bbq Wersquoll next start
Conclusion
Conclusion II
thinking about the effect of climate change on production γthough wersquoll make an aside to talk about measurement error first
Conclusion
Conclusion III
Each ppm of atmospheric CO2 corresponds to about 212 Gt C
and 778 Gt of CO2 Pay attention to the units people use
Not all gases are equal in their green house potential CO2 ismost common and most important but other gases are moreimportant per unit of emissions
Over the past 50 years about 55 of each emitted Gt of C
has stayed in the atmosphere The rest has been absorbed byland or oceans Thus it takes about 38 Gt C per 1ppm ofatmospheric CO2
Conclusion
Conclusion IV
Emissions are about 13Gt C for 2013 The rate at whichatmospheric CO2 is increasing has risen from about 1ppmyr1960s to 2ppm for 2000rsquos Since there is lots of fuel weshould expect atmospheric CO2 to continue to increase and atan increasing rate lsquobusiness as usual scenarios call foratmospheric CO2e gt 800 within 100 years
Not all countries are the same They are responsible fordifferent shares have different per capita emissions useemission more or less efficiently and are responsible fordifferent shares of historical emissions These factors are veryimportant obstacles to international agreements and alsosuggest the need for a richer model
Conclusion
Conclusion V
Steady state CO2 emissions are probably very small Sternsuggests less than 13 of current Our calculations suggest(1-055)=45
Review
Atmospheric CO2 concentrations are very high relative to theirlevels over the past 6-800k years
measured CO2 has increased monotonically to 412 ppm atMauna Loa observatory (July 2019)ice core record suggests we are at or above atmospheric CO2concentrations observed over past 6-800k years
Review
Atmospheric CO2 almost certainly causes global warming andclimate change
The physics relating atmospheric CO2 to warming iselementary and uncontroversial Earthrsquos radiation spectrumconfirms the theoryThe ice core record confirms the theoretical relationshipbetween CO2 and climateAerosols are probably unprecedented as is the rate of increaseof atmospheric CO2 and mean that we should not expect thehistorical record to predict the path of future climateWe use climate models to make these guesses There is a lotof uncertainty
Review
We also introduced the BDICE model
maxIM
u(c1 c2) (1)
st W = c1 + I + M (2)
c2 = (1 + r)I minus γ(T2 minus T1)I (3)
E = (1 minus ρ4MW
)(ρ5(c1 + I)) (4)
P2 = ρ0E + P1 (5)
T2 = ρ1(P2 minus P1) + T1 (6)
Last time we talked about the red parts
The last equation is a climate model We discussed all of thepieces of this model last time our endowment of temperatureand atmospheric CO2 along with climate models relatingatmospheric CO2 to climate
Review
The next to last equation is a model of the atmosphericcarbon cycle We discussed our endowment and projectedatmospheric CO2 last time
This time we want to talk about Emissions E ρ0 therelationship between emissions and concentration and ρ5 therelationship between consumption and emissions
Carbon cycle
Emissions and concentration of CO2
What is the relationship between emissions and atmosphericconcentration
Each ppm of atmospheric concentration is about 212 Gt C This is a standard conversion factor both IPCC and Hansenuse it (gigatons = billion tons)A molecule of CO2 is about 4412 as heavy as a molecule ofC Thus each ppm of atmospheric concentration of C isabout 212GtC times (4412) = 777GtCO2Hansen and IPCC 20072013 Physical Science Basismeasure emissions in terms of Gt C but Stern IPCC20072013 Mitigation of Climate Change measure emissionsin terms of Gt CO2 Social scientists often measure Green house gases in termsof CO2 equivalent emissions
In July 2019 the concentration of CO2 in the atmosphere was 412ppm This is equal to 873 Gt C and 3201 Gt CO2
Carbon cycle
CO2 is not the only GHG I
From Stern 2008 table 81
Carbon cycle
CO2 is not the only GHG II
July 2019 concentration of CO2 was 412 ppm Using thenumbers above current CO2e is 412077 = 535CO2e
From the forcing tables we see that non-CO2 is has about halfthe forcing capacity of CO2 However non-CO2 is lesspersistent so it makes a smaller total contribution to warmingthan this share suggests
Carbon cycle
What is lsquoGlobal Warming Potentialrsquo I
We would like to calculate the rate at which we are willing totrade CH4 for CO2 To do this define αt as the change inradiative forcing from one unit of concentration of the gas at t
ieWm2
PPM Define GWP as warming potential relative to CO2
GWP(CH4 ) =
int T0 αCH4 (t)dtint T0 αCO2 (t)dt
Example suppose t = 1 2 3 and for CO2 (αCO2 (1) αCO2 (2) αCO2 (3)) = (1 1 1) and for CH4 (αCH4 (1) αCH4 (2) αCH4 (3)) = (2 0 0)Then GWP(CH4 ) = 2+0+0
1+1+1
Carbon cycle
What is lsquoGlobal Warming Potentialrsquo II
Issues
T is completely arbitrary GWP of CH4 for T = 20 100 500 isabout 63 21 9We care about damage not radiative forcing (see Schmalensee The
Energy Journal (1993)) To see this considerIf we anticipate that the world will end in 20 years then neitherCO2 nor CH4 is very harmful but CH4 causes a lot morewarming over that time than CO2If we plan to spend the next 20 years as we do now but then topermanently convert to an economy based on penguinfarming then CH4 emissions now are not very harmful but CO2is (because it is persistent)
We canrsquot really assign relative values to CO2 and CH4 until wesolve for the whole optimal path of emissions for both gasesso any definition of GWP is going to be unsatisfactory
Carbon cycle
Units
Stern 2007 p193 gives CO2e emissions for 2000 as 42Gt CO2e Hansen has 85 Gt C from fossil fuelCan we reconcile these numbers(Yes)
About 77 of CO2e is CO2
About 18 of CO2 is non fossil fuel (more on this later)
Stern reports CO2 Hansen C
so Sternrsquos 42 Gt CO2e becomes42 times (77(1 minus 18))times (1244) = 72 Gt of atmospheric C It would be closer but Stern uses 2000 numbers and Hansenrsquos 85is for about 2008
Atmospheric carbon cycle
Carbon cycle
Carbon is cycled back and forth between the atmosphere oceanand land by biological and chemical processes This means thatemissions donrsquot translate immediately into atmosphericconcentrations Stocksannual flows of C (not CO2 ) are
Atmosphere 800+45Gt
Ocean 40000+3Gt
Volcanos ndash-01Gt
Forests 600-16 Gt
Fossil fuels 5000-85
Sediments ndash-1Gt
Atmospheric carbon cycle
Fossil fuel emissions and deforestation put about 10Gt C in theatmosphere (ca 2007) Atmospheric C increased by about 45GtAbout 3Gt are absorbed by the ocean The remaining 25Gt arethought to be absorbed by plants (NB old numbers to go withfigure) Numbers from Hansen 2009 about the same as in Jacob 1999
Black = natural Red=Anthropogenic AOGCM models of carbon cycle are complicated IPCC 2007 Physical Science basis
figure 73
Atmospheric carbon cycle
Atmospheric CO2 cycle data I
Another way to see this is to look at the relationship betweenemissions and concentration directly
Calculate annual change in C ppm from Mauna Loa (eg)
Calculate annual emissions using emissions rates andconsumption data (more below)
Calculate ratio ∆CO2ppmFossil Fuel emissions = concentration yield of
emissions
Atmospheric carbon cycle
Atmospheric CO2 cycle data II
1950 1960 1970 1980 1990 2000 2010 0
2
4
6
8
10
Global Fossil Fuel CO2 EmissionsCO2 Airborne Fraction (7minusyear mean)
Em
issi
ons
(Gig
aton
s C
yea
r)
0
20
40
60
80
100
Air
born
e Fr
actio
n (
)
Hansen 2009 figure 16
Atmospheric carbon cycle
Atmospheric CO2 cycle data III
So concentration yield of emissions is about 55 Thus
(1055)= 18 Gt C emissions gives 1 Gt ton of atmospheric C
212 Gt atmospheric C to gives 1ppm atmospheric C (or CO2 )
Multiplying 18 times 212 = 38Gt C of emissions to get 1ppm ofatmospheric concentration
Recall the carbon cycle equation from our model
P2 = ρ0E + P1
We have just calculated that ρ0 = 138 = 026ppm C (or CO2 )
Gt C
What is ρ0 if we denominate emissions in terms of CO2
Atmospheric carbon cycle
Atmospheric CO2 cycle data IV
In Hansenrsquos graph the fraction of emissions retained in theatmosphere is CONSTANT as emissions are increasing This isthought to reflect increased absorbtion by plant lsquocarbonfertilizationrsquo or increased lsquonet primary productivityrsquo
In AOGCMrsquos the carbon cycle is modelled very carefully We reallywant to deal with the possibility that absorbtion varies withtemperature or CO2 (it probably does) and there is a lot ofuncertainty about this relationship
Consumption and emissions
Emissions for particular activities I
CO2 from gasoline 23 kgliter = 194 poundsgallon So1000 kg of CO2 emission results from 435 liters or 114gallons of gas (about 1 not burned is mostly N2O so CO2e ishigher)
CO2 from diesel 27 kgliter = 222 poundsgallon 1000 kg ofCO2 emission results from 370 liters or 97 gallons of dieselhttpwwwepagovotaqclimate420f05001htmcalculating
BBQ propane tank about 18 pounds propane = 24kg = 53 lbCO2 (NB Gasoline weighs 63 poundsgallon so 18 poundsof gas gives about 54 pounds CO2 Propane has morehydrogen per carbon atom than gasoline)
Consumption and emissions
Emissions for particular activities II
CO2 sequestration by 1 acre 90 year old pine forest inSoutheastern US is about 100 tons C about 1 tonacreyearSo burning this acre releases about 100 tons C or 367 tonsCO2 httpwwwepagovsequestrationfaqhtml For tropical forests about 18times as much not reliable source
CO2 from coal about 200 tons CO2 per ton (a lot of the stuffin coal is not burned ndash I think) or 2100lb CO2 per 1000 KWHfrom non-baseload coal burning electricity generation CO2eis higher Baseload will usually be lower (often nuclear orhydro) httpwwweiagovtoolsfaqsfaqcfmid=74ampt=11
Consumption and emissions
Emissions for particular activities III
For natural gas about 1200lb CO2 per 1000 KWH Sofracking is fantastic unless too much methane leaks beforeitrsquos burnt With 1 ton of methane worth 23 tons of CO2 about43 leakage makes coal and natural gas even (unless thereis methane leakage from coal mines) The rate of leakage iscurrently contested EPA current estimate is about 06 but05 is probably better (Allen et al PNAS 2013)
For reference Avg household in RI = 500KWHmo Avghousehold in TX = 1000KWHmohttpswwweiagovtoolsfaqsfaqcfmid=97ampt=3 (Feb 2016) Or averagehousehold in Providence sim 8000kwhyear in 2001 Dallas sim18500kwhyear (Glaeser and Kahn JUE 2010)
Consumption and emissions
Emissions for particular activities IV
For thinking about fracking also consider the following
Consumption and emissions
Global emissions per unit of consumption ca 2013
Using these sorts of particular numbers together with informationabout aggregate consumption one can calculate world emissions
Global annual emissions ca 2013 are about 49Gt CO2e or49 times 12
44 sim 133 Gt C (more on this later)
World GDP in 2013 is about 77 trillion USD (NB this is W inour model)
Dividingwe have 133times109 tons C77times1012000USD = 133
7700ton CUSD sim 017 kg C
USD (1 ton= 1000 kg) Multiply by 4412 for CO2 instead of C
Recall the third equation from our global warming model
E = (1 minus ρ4MW
)(ρ5(c1 + I)) (7)
Wersquove just calculated ρ5 Why is this sloppy
Consumption and emissions
Emissions per unit of consumption by countryItrsquos also interesting to look at the country by countrybreakdown(ca 2004) The US and Canada make a lot of stuffper ton of emissions
IPCC 2007 Mitigation fig SPM3b
What if China and Africa made same output at USCAemission rates This is why technology transfer is importantCompare 068 kg CO2e per dollar ca 2004 to my calculationof 017 kg C per dollar 2013 How important is technicalprogress
Consumption and emissions
Technological progress I
httpwww3epagovclimatechangescienceindicatorsghgus-ghg-emissionshtml January 2016
Consumption and emissions
Technological progress II
Nordhaus does this calculation every year country by country
Russia
India
World
EU
US
China
Consumption and emissions
Emissions - Summary
Wersquove now calculated ρ5 emissions per GDP at about 017kgC per dollar ca 2013Looking at the data a little more carefully highlights twodeficiencies on our model
Technological progress is at work so this ratio changes overtimeThere are huge difference across places in this ratio
This highlights the importance of technological progress andtechnology transfer in solving the problem of climate change
Wersquoll address this when we get to the Nordhaus model
Emissions
Emissions trends and levels
Recall
maxIM
u(c1 c2) (8)
st W = c1 + I + M (9)
c2 = (1 + r)I minus γ(T2 minus T1)I (10)
E = (1 minus ρ4MW
)(ρ5(c1 + I)) (11)
P2 = ρ0E + P1 (12)
T2 = ρ1(P2 minus P1) + T1 (13)
Wersquove filled in a bit more The next step is to look at E This meanslooking at trends and levels in CO2 emissions
Emissions
CO2e 1970-2010
IPCC 2013 WG3 fig TS1
Right panel gives confidence bounds for 2010 49Gt CO2e in 2010
Emissions
CO2 by purpose and country income 1750-2010
IPCC 2013 WG3 fig TS2
Emissions
Hansenrsquos version of the same thing
Flow StockHansen 2009 fig 27
Contributions to stock and flow are very different At thenegotiating table developing countries want the right to emit sinceeveryone else had their turn
Emissions
2010 CO2e by purpose
IPCC 2013 WG3 fig TS3
Emissions
2010 CO2e by purpose and country income
IPCC 2013 WG3 fig TS3
Emissions
US 1990-2017 CO2e
ES-4 Inventory of US Greenhouse Gas Emissions and Sinks 1990ndash2017
ES2 Recent Trends in US Greenhouse Gas Emissions and Sinks
In 2017 total gross US greenhouse gas emissions were 64567 MMT or million metric tons of carbon dioxide (CO2) Eq11 Total US emissions have increased by 13 percent from 1990 to 2017 and emissions decreased from 2016 to 2017 by 05 percent (355 MMT CO2 Eq) The decrease in total greenhouse gas emissions between 2016 and 2017 was driven in part by a decrease in CO2 emissions from fossil fuel combustion The decrease in CO2 emissions from fossil fuel combustion was a result of multiple factors including a continued shift from coal to natural gas and increased use of renewable energy in the electric power sector and milder weather that contributed to less overall electricity use
Relative to 1990 the baseline for this Inventory gross emissions in 2017 are higher by 13 percent down from a high of 157 percent above 1990 levels in 2007 Overall net emissions in 2017 were 130 percent below 2005 levels as shown in Table ES-2 Figure ES-1 through Figure ES-3 illustrate the overall trends in total US emissions by gas annual changes and absolute change since 1990 and Table ES-2 provides a detailed summary of gross US greenhouse gas emissions and sinks for 1990 through 2017 Note unless otherwise stated all tables and figures provide total gross emissions and exclude the greenhouse gas fluxes from the Land Use Land-Use Change and Forestry (LULUCF) sector (see Section ES3 Overview of Sector Emissions and Trends)
Figure ES-1 Gross US Greenhouse Gas Emissions by Gas (MMT CO2 Eq)
11 The gross emissions total presented in this report for the United States excludes emissions and removals from Land Use Land-Use Change and Forestry (LULUCF) The net emissions total presented in this report for the United States includes emissions and removals from LULUCF
httpswwwepagovsitesproductionfiles2019-04documentsus-ghg-inventory-2019-main-textpdf September 2019
This reflects fracking recession technical progress off-shoring ofmanufacturing Emissions are likely up since 2017
Emissions
Emissions per person
Itrsquos also interesting to look at the country by country breakdown interms of emissions per capita
IPCC 2007 Mitigation fig SPM3a
As of 2012 US had 454 tons C person and for India this numberwas 046 China was 18(httpcdiacornlgovtrendsemistop2011cap)
Emissions
The problem of stabilizing atmospheric CO2Emissions are about 13Gt C per year
The ocean and biosphere absorb about 45 of emissions (sofar)
This means the ocean and biosphere absorb 13 times 045 asymp 6GtC per year
As a rough guess this means that reducing emissions to 6GtC per year will stabilize atmospheric CO2 (but not climate)
This involves a 55 decrease For an average American thismeans this means reducing emissions from 45 tons per yearto about 20 if US share of total emissions stays constant Ifemissions are allocated equally to each of the worldrsquos 74bpeople then each of us gets 6Gt C 74b people or about 08ton This is an 82 decrease for the average American It isalso about the twice the level of the average Indian and halfthat of the average Chinese
Emissions
Summary
2013 emissions of CO2e were about 49Gt Of this 35Gt wasCO2 and of this about 30Gt from fossil fuels and 5Gt fromland use change and agriculture This is E in our model
Emission are growing rapidly about 2year between 2000and 2010 1970 CO2e was 30Gt
2010 CO2e 14 transport 18 buildings 21 industry 24AFOLU We could use this to calculate refinements of ρ5
The countries responsible for most of the stock are not thecountries responsible for most of the flow
Per capita emissions vary by a factor of about 10 between richand poor countries
There has been a decline in US emissions since 2008 due tofracking recession technical progress off shoring
Peak oil
Will we run out of fossil fuel INot soon enough to matter
0
200
400
600
800
Estimated Reserves
Emissions to Date
Gig
aton
s C
arbo
n
Oil Gas Coal Land Use
EIA
IPCCEIA
IPCC
100
200
300
Em
itted
CO
2 (p
pm)
0
200
400
600
800
We have oceans of coal and lots of oil and these figures predateUS fracking
Peak oil
Will we run out of fossil fuel II
Conclusion
Conclusion I
Here is where we stand with our model
maxIM
u(c1 c2) (14)
st W = c1 + I + M (15)
c2 = (1 + r)I minus γ(T2 minus T1)I (16)
E = (1 minus ρ4MW
)(ρ5(c1 + I)) (17)
P2 = ρ0E + P1 (18)
T2 = ρ1(P2 minus P1) + T1 (19)
We have enough pieces filled in to permit you to calculate theimpact on future climate of particular sorts of current consumptioneg burning a tank of propane on your bbq Wersquoll next start
Conclusion
Conclusion II
thinking about the effect of climate change on production γthough wersquoll make an aside to talk about measurement error first
Conclusion
Conclusion III
Each ppm of atmospheric CO2 corresponds to about 212 Gt C
and 778 Gt of CO2 Pay attention to the units people use
Not all gases are equal in their green house potential CO2 ismost common and most important but other gases are moreimportant per unit of emissions
Over the past 50 years about 55 of each emitted Gt of C
has stayed in the atmosphere The rest has been absorbed byland or oceans Thus it takes about 38 Gt C per 1ppm ofatmospheric CO2
Conclusion
Conclusion IV
Emissions are about 13Gt C for 2013 The rate at whichatmospheric CO2 is increasing has risen from about 1ppmyr1960s to 2ppm for 2000rsquos Since there is lots of fuel weshould expect atmospheric CO2 to continue to increase and atan increasing rate lsquobusiness as usual scenarios call foratmospheric CO2e gt 800 within 100 years
Not all countries are the same They are responsible fordifferent shares have different per capita emissions useemission more or less efficiently and are responsible fordifferent shares of historical emissions These factors are veryimportant obstacles to international agreements and alsosuggest the need for a richer model
Conclusion
Conclusion V
Steady state CO2 emissions are probably very small Sternsuggests less than 13 of current Our calculations suggest(1-055)=45
Review
Atmospheric CO2 almost certainly causes global warming andclimate change
The physics relating atmospheric CO2 to warming iselementary and uncontroversial Earthrsquos radiation spectrumconfirms the theoryThe ice core record confirms the theoretical relationshipbetween CO2 and climateAerosols are probably unprecedented as is the rate of increaseof atmospheric CO2 and mean that we should not expect thehistorical record to predict the path of future climateWe use climate models to make these guesses There is a lotof uncertainty
Review
We also introduced the BDICE model
maxIM
u(c1 c2) (1)
st W = c1 + I + M (2)
c2 = (1 + r)I minus γ(T2 minus T1)I (3)
E = (1 minus ρ4MW
)(ρ5(c1 + I)) (4)
P2 = ρ0E + P1 (5)
T2 = ρ1(P2 minus P1) + T1 (6)
Last time we talked about the red parts
The last equation is a climate model We discussed all of thepieces of this model last time our endowment of temperatureand atmospheric CO2 along with climate models relatingatmospheric CO2 to climate
Review
The next to last equation is a model of the atmosphericcarbon cycle We discussed our endowment and projectedatmospheric CO2 last time
This time we want to talk about Emissions E ρ0 therelationship between emissions and concentration and ρ5 therelationship between consumption and emissions
Carbon cycle
Emissions and concentration of CO2
What is the relationship between emissions and atmosphericconcentration
Each ppm of atmospheric concentration is about 212 Gt C This is a standard conversion factor both IPCC and Hansenuse it (gigatons = billion tons)A molecule of CO2 is about 4412 as heavy as a molecule ofC Thus each ppm of atmospheric concentration of C isabout 212GtC times (4412) = 777GtCO2Hansen and IPCC 20072013 Physical Science Basismeasure emissions in terms of Gt C but Stern IPCC20072013 Mitigation of Climate Change measure emissionsin terms of Gt CO2 Social scientists often measure Green house gases in termsof CO2 equivalent emissions
In July 2019 the concentration of CO2 in the atmosphere was 412ppm This is equal to 873 Gt C and 3201 Gt CO2
Carbon cycle
CO2 is not the only GHG I
From Stern 2008 table 81
Carbon cycle
CO2 is not the only GHG II
July 2019 concentration of CO2 was 412 ppm Using thenumbers above current CO2e is 412077 = 535CO2e
From the forcing tables we see that non-CO2 is has about halfthe forcing capacity of CO2 However non-CO2 is lesspersistent so it makes a smaller total contribution to warmingthan this share suggests
Carbon cycle
What is lsquoGlobal Warming Potentialrsquo I
We would like to calculate the rate at which we are willing totrade CH4 for CO2 To do this define αt as the change inradiative forcing from one unit of concentration of the gas at t
ieWm2
PPM Define GWP as warming potential relative to CO2
GWP(CH4 ) =
int T0 αCH4 (t)dtint T0 αCO2 (t)dt
Example suppose t = 1 2 3 and for CO2 (αCO2 (1) αCO2 (2) αCO2 (3)) = (1 1 1) and for CH4 (αCH4 (1) αCH4 (2) αCH4 (3)) = (2 0 0)Then GWP(CH4 ) = 2+0+0
1+1+1
Carbon cycle
What is lsquoGlobal Warming Potentialrsquo II
Issues
T is completely arbitrary GWP of CH4 for T = 20 100 500 isabout 63 21 9We care about damage not radiative forcing (see Schmalensee The
Energy Journal (1993)) To see this considerIf we anticipate that the world will end in 20 years then neitherCO2 nor CH4 is very harmful but CH4 causes a lot morewarming over that time than CO2If we plan to spend the next 20 years as we do now but then topermanently convert to an economy based on penguinfarming then CH4 emissions now are not very harmful but CO2is (because it is persistent)
We canrsquot really assign relative values to CO2 and CH4 until wesolve for the whole optimal path of emissions for both gasesso any definition of GWP is going to be unsatisfactory
Carbon cycle
Units
Stern 2007 p193 gives CO2e emissions for 2000 as 42Gt CO2e Hansen has 85 Gt C from fossil fuelCan we reconcile these numbers(Yes)
About 77 of CO2e is CO2
About 18 of CO2 is non fossil fuel (more on this later)
Stern reports CO2 Hansen C
so Sternrsquos 42 Gt CO2e becomes42 times (77(1 minus 18))times (1244) = 72 Gt of atmospheric C It would be closer but Stern uses 2000 numbers and Hansenrsquos 85is for about 2008
Atmospheric carbon cycle
Carbon cycle
Carbon is cycled back and forth between the atmosphere oceanand land by biological and chemical processes This means thatemissions donrsquot translate immediately into atmosphericconcentrations Stocksannual flows of C (not CO2 ) are
Atmosphere 800+45Gt
Ocean 40000+3Gt
Volcanos ndash-01Gt
Forests 600-16 Gt
Fossil fuels 5000-85
Sediments ndash-1Gt
Atmospheric carbon cycle
Fossil fuel emissions and deforestation put about 10Gt C in theatmosphere (ca 2007) Atmospheric C increased by about 45GtAbout 3Gt are absorbed by the ocean The remaining 25Gt arethought to be absorbed by plants (NB old numbers to go withfigure) Numbers from Hansen 2009 about the same as in Jacob 1999
Black = natural Red=Anthropogenic AOGCM models of carbon cycle are complicated IPCC 2007 Physical Science basis
figure 73
Atmospheric carbon cycle
Atmospheric CO2 cycle data I
Another way to see this is to look at the relationship betweenemissions and concentration directly
Calculate annual change in C ppm from Mauna Loa (eg)
Calculate annual emissions using emissions rates andconsumption data (more below)
Calculate ratio ∆CO2ppmFossil Fuel emissions = concentration yield of
emissions
Atmospheric carbon cycle
Atmospheric CO2 cycle data II
1950 1960 1970 1980 1990 2000 2010 0
2
4
6
8
10
Global Fossil Fuel CO2 EmissionsCO2 Airborne Fraction (7minusyear mean)
Em
issi
ons
(Gig
aton
s C
yea
r)
0
20
40
60
80
100
Air
born
e Fr
actio
n (
)
Hansen 2009 figure 16
Atmospheric carbon cycle
Atmospheric CO2 cycle data III
So concentration yield of emissions is about 55 Thus
(1055)= 18 Gt C emissions gives 1 Gt ton of atmospheric C
212 Gt atmospheric C to gives 1ppm atmospheric C (or CO2 )
Multiplying 18 times 212 = 38Gt C of emissions to get 1ppm ofatmospheric concentration
Recall the carbon cycle equation from our model
P2 = ρ0E + P1
We have just calculated that ρ0 = 138 = 026ppm C (or CO2 )
Gt C
What is ρ0 if we denominate emissions in terms of CO2
Atmospheric carbon cycle
Atmospheric CO2 cycle data IV
In Hansenrsquos graph the fraction of emissions retained in theatmosphere is CONSTANT as emissions are increasing This isthought to reflect increased absorbtion by plant lsquocarbonfertilizationrsquo or increased lsquonet primary productivityrsquo
In AOGCMrsquos the carbon cycle is modelled very carefully We reallywant to deal with the possibility that absorbtion varies withtemperature or CO2 (it probably does) and there is a lot ofuncertainty about this relationship
Consumption and emissions
Emissions for particular activities I
CO2 from gasoline 23 kgliter = 194 poundsgallon So1000 kg of CO2 emission results from 435 liters or 114gallons of gas (about 1 not burned is mostly N2O so CO2e ishigher)
CO2 from diesel 27 kgliter = 222 poundsgallon 1000 kg ofCO2 emission results from 370 liters or 97 gallons of dieselhttpwwwepagovotaqclimate420f05001htmcalculating
BBQ propane tank about 18 pounds propane = 24kg = 53 lbCO2 (NB Gasoline weighs 63 poundsgallon so 18 poundsof gas gives about 54 pounds CO2 Propane has morehydrogen per carbon atom than gasoline)
Consumption and emissions
Emissions for particular activities II
CO2 sequestration by 1 acre 90 year old pine forest inSoutheastern US is about 100 tons C about 1 tonacreyearSo burning this acre releases about 100 tons C or 367 tonsCO2 httpwwwepagovsequestrationfaqhtml For tropical forests about 18times as much not reliable source
CO2 from coal about 200 tons CO2 per ton (a lot of the stuffin coal is not burned ndash I think) or 2100lb CO2 per 1000 KWHfrom non-baseload coal burning electricity generation CO2eis higher Baseload will usually be lower (often nuclear orhydro) httpwwweiagovtoolsfaqsfaqcfmid=74ampt=11
Consumption and emissions
Emissions for particular activities III
For natural gas about 1200lb CO2 per 1000 KWH Sofracking is fantastic unless too much methane leaks beforeitrsquos burnt With 1 ton of methane worth 23 tons of CO2 about43 leakage makes coal and natural gas even (unless thereis methane leakage from coal mines) The rate of leakage iscurrently contested EPA current estimate is about 06 but05 is probably better (Allen et al PNAS 2013)
For reference Avg household in RI = 500KWHmo Avghousehold in TX = 1000KWHmohttpswwweiagovtoolsfaqsfaqcfmid=97ampt=3 (Feb 2016) Or averagehousehold in Providence sim 8000kwhyear in 2001 Dallas sim18500kwhyear (Glaeser and Kahn JUE 2010)
Consumption and emissions
Emissions for particular activities IV
For thinking about fracking also consider the following
Consumption and emissions
Global emissions per unit of consumption ca 2013
Using these sorts of particular numbers together with informationabout aggregate consumption one can calculate world emissions
Global annual emissions ca 2013 are about 49Gt CO2e or49 times 12
44 sim 133 Gt C (more on this later)
World GDP in 2013 is about 77 trillion USD (NB this is W inour model)
Dividingwe have 133times109 tons C77times1012000USD = 133
7700ton CUSD sim 017 kg C
USD (1 ton= 1000 kg) Multiply by 4412 for CO2 instead of C
Recall the third equation from our global warming model
E = (1 minus ρ4MW
)(ρ5(c1 + I)) (7)
Wersquove just calculated ρ5 Why is this sloppy
Consumption and emissions
Emissions per unit of consumption by countryItrsquos also interesting to look at the country by countrybreakdown(ca 2004) The US and Canada make a lot of stuffper ton of emissions
IPCC 2007 Mitigation fig SPM3b
What if China and Africa made same output at USCAemission rates This is why technology transfer is importantCompare 068 kg CO2e per dollar ca 2004 to my calculationof 017 kg C per dollar 2013 How important is technicalprogress
Consumption and emissions
Technological progress I
httpwww3epagovclimatechangescienceindicatorsghgus-ghg-emissionshtml January 2016
Consumption and emissions
Technological progress II
Nordhaus does this calculation every year country by country
Russia
India
World
EU
US
China
Consumption and emissions
Emissions - Summary
Wersquove now calculated ρ5 emissions per GDP at about 017kgC per dollar ca 2013Looking at the data a little more carefully highlights twodeficiencies on our model
Technological progress is at work so this ratio changes overtimeThere are huge difference across places in this ratio
This highlights the importance of technological progress andtechnology transfer in solving the problem of climate change
Wersquoll address this when we get to the Nordhaus model
Emissions
Emissions trends and levels
Recall
maxIM
u(c1 c2) (8)
st W = c1 + I + M (9)
c2 = (1 + r)I minus γ(T2 minus T1)I (10)
E = (1 minus ρ4MW
)(ρ5(c1 + I)) (11)
P2 = ρ0E + P1 (12)
T2 = ρ1(P2 minus P1) + T1 (13)
Wersquove filled in a bit more The next step is to look at E This meanslooking at trends and levels in CO2 emissions
Emissions
CO2e 1970-2010
IPCC 2013 WG3 fig TS1
Right panel gives confidence bounds for 2010 49Gt CO2e in 2010
Emissions
CO2 by purpose and country income 1750-2010
IPCC 2013 WG3 fig TS2
Emissions
Hansenrsquos version of the same thing
Flow StockHansen 2009 fig 27
Contributions to stock and flow are very different At thenegotiating table developing countries want the right to emit sinceeveryone else had their turn
Emissions
2010 CO2e by purpose
IPCC 2013 WG3 fig TS3
Emissions
2010 CO2e by purpose and country income
IPCC 2013 WG3 fig TS3
Emissions
US 1990-2017 CO2e
ES-4 Inventory of US Greenhouse Gas Emissions and Sinks 1990ndash2017
ES2 Recent Trends in US Greenhouse Gas Emissions and Sinks
In 2017 total gross US greenhouse gas emissions were 64567 MMT or million metric tons of carbon dioxide (CO2) Eq11 Total US emissions have increased by 13 percent from 1990 to 2017 and emissions decreased from 2016 to 2017 by 05 percent (355 MMT CO2 Eq) The decrease in total greenhouse gas emissions between 2016 and 2017 was driven in part by a decrease in CO2 emissions from fossil fuel combustion The decrease in CO2 emissions from fossil fuel combustion was a result of multiple factors including a continued shift from coal to natural gas and increased use of renewable energy in the electric power sector and milder weather that contributed to less overall electricity use
Relative to 1990 the baseline for this Inventory gross emissions in 2017 are higher by 13 percent down from a high of 157 percent above 1990 levels in 2007 Overall net emissions in 2017 were 130 percent below 2005 levels as shown in Table ES-2 Figure ES-1 through Figure ES-3 illustrate the overall trends in total US emissions by gas annual changes and absolute change since 1990 and Table ES-2 provides a detailed summary of gross US greenhouse gas emissions and sinks for 1990 through 2017 Note unless otherwise stated all tables and figures provide total gross emissions and exclude the greenhouse gas fluxes from the Land Use Land-Use Change and Forestry (LULUCF) sector (see Section ES3 Overview of Sector Emissions and Trends)
Figure ES-1 Gross US Greenhouse Gas Emissions by Gas (MMT CO2 Eq)
11 The gross emissions total presented in this report for the United States excludes emissions and removals from Land Use Land-Use Change and Forestry (LULUCF) The net emissions total presented in this report for the United States includes emissions and removals from LULUCF
httpswwwepagovsitesproductionfiles2019-04documentsus-ghg-inventory-2019-main-textpdf September 2019
This reflects fracking recession technical progress off-shoring ofmanufacturing Emissions are likely up since 2017
Emissions
Emissions per person
Itrsquos also interesting to look at the country by country breakdown interms of emissions per capita
IPCC 2007 Mitigation fig SPM3a
As of 2012 US had 454 tons C person and for India this numberwas 046 China was 18(httpcdiacornlgovtrendsemistop2011cap)
Emissions
The problem of stabilizing atmospheric CO2Emissions are about 13Gt C per year
The ocean and biosphere absorb about 45 of emissions (sofar)
This means the ocean and biosphere absorb 13 times 045 asymp 6GtC per year
As a rough guess this means that reducing emissions to 6GtC per year will stabilize atmospheric CO2 (but not climate)
This involves a 55 decrease For an average American thismeans this means reducing emissions from 45 tons per yearto about 20 if US share of total emissions stays constant Ifemissions are allocated equally to each of the worldrsquos 74bpeople then each of us gets 6Gt C 74b people or about 08ton This is an 82 decrease for the average American It isalso about the twice the level of the average Indian and halfthat of the average Chinese
Emissions
Summary
2013 emissions of CO2e were about 49Gt Of this 35Gt wasCO2 and of this about 30Gt from fossil fuels and 5Gt fromland use change and agriculture This is E in our model
Emission are growing rapidly about 2year between 2000and 2010 1970 CO2e was 30Gt
2010 CO2e 14 transport 18 buildings 21 industry 24AFOLU We could use this to calculate refinements of ρ5
The countries responsible for most of the stock are not thecountries responsible for most of the flow
Per capita emissions vary by a factor of about 10 between richand poor countries
There has been a decline in US emissions since 2008 due tofracking recession technical progress off shoring
Peak oil
Will we run out of fossil fuel INot soon enough to matter
0
200
400
600
800
Estimated Reserves
Emissions to Date
Gig
aton
s C
arbo
n
Oil Gas Coal Land Use
EIA
IPCCEIA
IPCC
100
200
300
Em
itted
CO
2 (p
pm)
0
200
400
600
800
We have oceans of coal and lots of oil and these figures predateUS fracking
Peak oil
Will we run out of fossil fuel II
Conclusion
Conclusion I
Here is where we stand with our model
maxIM
u(c1 c2) (14)
st W = c1 + I + M (15)
c2 = (1 + r)I minus γ(T2 minus T1)I (16)
E = (1 minus ρ4MW
)(ρ5(c1 + I)) (17)
P2 = ρ0E + P1 (18)
T2 = ρ1(P2 minus P1) + T1 (19)
We have enough pieces filled in to permit you to calculate theimpact on future climate of particular sorts of current consumptioneg burning a tank of propane on your bbq Wersquoll next start
Conclusion
Conclusion II
thinking about the effect of climate change on production γthough wersquoll make an aside to talk about measurement error first
Conclusion
Conclusion III
Each ppm of atmospheric CO2 corresponds to about 212 Gt C
and 778 Gt of CO2 Pay attention to the units people use
Not all gases are equal in their green house potential CO2 ismost common and most important but other gases are moreimportant per unit of emissions
Over the past 50 years about 55 of each emitted Gt of C
has stayed in the atmosphere The rest has been absorbed byland or oceans Thus it takes about 38 Gt C per 1ppm ofatmospheric CO2
Conclusion
Conclusion IV
Emissions are about 13Gt C for 2013 The rate at whichatmospheric CO2 is increasing has risen from about 1ppmyr1960s to 2ppm for 2000rsquos Since there is lots of fuel weshould expect atmospheric CO2 to continue to increase and atan increasing rate lsquobusiness as usual scenarios call foratmospheric CO2e gt 800 within 100 years
Not all countries are the same They are responsible fordifferent shares have different per capita emissions useemission more or less efficiently and are responsible fordifferent shares of historical emissions These factors are veryimportant obstacles to international agreements and alsosuggest the need for a richer model
Conclusion
Conclusion V
Steady state CO2 emissions are probably very small Sternsuggests less than 13 of current Our calculations suggest(1-055)=45
Review
We also introduced the BDICE model
maxIM
u(c1 c2) (1)
st W = c1 + I + M (2)
c2 = (1 + r)I minus γ(T2 minus T1)I (3)
E = (1 minus ρ4MW
)(ρ5(c1 + I)) (4)
P2 = ρ0E + P1 (5)
T2 = ρ1(P2 minus P1) + T1 (6)
Last time we talked about the red parts
The last equation is a climate model We discussed all of thepieces of this model last time our endowment of temperatureand atmospheric CO2 along with climate models relatingatmospheric CO2 to climate
Review
The next to last equation is a model of the atmosphericcarbon cycle We discussed our endowment and projectedatmospheric CO2 last time
This time we want to talk about Emissions E ρ0 therelationship between emissions and concentration and ρ5 therelationship between consumption and emissions
Carbon cycle
Emissions and concentration of CO2
What is the relationship between emissions and atmosphericconcentration
Each ppm of atmospheric concentration is about 212 Gt C This is a standard conversion factor both IPCC and Hansenuse it (gigatons = billion tons)A molecule of CO2 is about 4412 as heavy as a molecule ofC Thus each ppm of atmospheric concentration of C isabout 212GtC times (4412) = 777GtCO2Hansen and IPCC 20072013 Physical Science Basismeasure emissions in terms of Gt C but Stern IPCC20072013 Mitigation of Climate Change measure emissionsin terms of Gt CO2 Social scientists often measure Green house gases in termsof CO2 equivalent emissions
In July 2019 the concentration of CO2 in the atmosphere was 412ppm This is equal to 873 Gt C and 3201 Gt CO2
Carbon cycle
CO2 is not the only GHG I
From Stern 2008 table 81
Carbon cycle
CO2 is not the only GHG II
July 2019 concentration of CO2 was 412 ppm Using thenumbers above current CO2e is 412077 = 535CO2e
From the forcing tables we see that non-CO2 is has about halfthe forcing capacity of CO2 However non-CO2 is lesspersistent so it makes a smaller total contribution to warmingthan this share suggests
Carbon cycle
What is lsquoGlobal Warming Potentialrsquo I
We would like to calculate the rate at which we are willing totrade CH4 for CO2 To do this define αt as the change inradiative forcing from one unit of concentration of the gas at t
ieWm2
PPM Define GWP as warming potential relative to CO2
GWP(CH4 ) =
int T0 αCH4 (t)dtint T0 αCO2 (t)dt
Example suppose t = 1 2 3 and for CO2 (αCO2 (1) αCO2 (2) αCO2 (3)) = (1 1 1) and for CH4 (αCH4 (1) αCH4 (2) αCH4 (3)) = (2 0 0)Then GWP(CH4 ) = 2+0+0
1+1+1
Carbon cycle
What is lsquoGlobal Warming Potentialrsquo II
Issues
T is completely arbitrary GWP of CH4 for T = 20 100 500 isabout 63 21 9We care about damage not radiative forcing (see Schmalensee The
Energy Journal (1993)) To see this considerIf we anticipate that the world will end in 20 years then neitherCO2 nor CH4 is very harmful but CH4 causes a lot morewarming over that time than CO2If we plan to spend the next 20 years as we do now but then topermanently convert to an economy based on penguinfarming then CH4 emissions now are not very harmful but CO2is (because it is persistent)
We canrsquot really assign relative values to CO2 and CH4 until wesolve for the whole optimal path of emissions for both gasesso any definition of GWP is going to be unsatisfactory
Carbon cycle
Units
Stern 2007 p193 gives CO2e emissions for 2000 as 42Gt CO2e Hansen has 85 Gt C from fossil fuelCan we reconcile these numbers(Yes)
About 77 of CO2e is CO2
About 18 of CO2 is non fossil fuel (more on this later)
Stern reports CO2 Hansen C
so Sternrsquos 42 Gt CO2e becomes42 times (77(1 minus 18))times (1244) = 72 Gt of atmospheric C It would be closer but Stern uses 2000 numbers and Hansenrsquos 85is for about 2008
Atmospheric carbon cycle
Carbon cycle
Carbon is cycled back and forth between the atmosphere oceanand land by biological and chemical processes This means thatemissions donrsquot translate immediately into atmosphericconcentrations Stocksannual flows of C (not CO2 ) are
Atmosphere 800+45Gt
Ocean 40000+3Gt
Volcanos ndash-01Gt
Forests 600-16 Gt
Fossil fuels 5000-85
Sediments ndash-1Gt
Atmospheric carbon cycle
Fossil fuel emissions and deforestation put about 10Gt C in theatmosphere (ca 2007) Atmospheric C increased by about 45GtAbout 3Gt are absorbed by the ocean The remaining 25Gt arethought to be absorbed by plants (NB old numbers to go withfigure) Numbers from Hansen 2009 about the same as in Jacob 1999
Black = natural Red=Anthropogenic AOGCM models of carbon cycle are complicated IPCC 2007 Physical Science basis
figure 73
Atmospheric carbon cycle
Atmospheric CO2 cycle data I
Another way to see this is to look at the relationship betweenemissions and concentration directly
Calculate annual change in C ppm from Mauna Loa (eg)
Calculate annual emissions using emissions rates andconsumption data (more below)
Calculate ratio ∆CO2ppmFossil Fuel emissions = concentration yield of
emissions
Atmospheric carbon cycle
Atmospheric CO2 cycle data II
1950 1960 1970 1980 1990 2000 2010 0
2
4
6
8
10
Global Fossil Fuel CO2 EmissionsCO2 Airborne Fraction (7minusyear mean)
Em
issi
ons
(Gig
aton
s C
yea
r)
0
20
40
60
80
100
Air
born
e Fr
actio
n (
)
Hansen 2009 figure 16
Atmospheric carbon cycle
Atmospheric CO2 cycle data III
So concentration yield of emissions is about 55 Thus
(1055)= 18 Gt C emissions gives 1 Gt ton of atmospheric C
212 Gt atmospheric C to gives 1ppm atmospheric C (or CO2 )
Multiplying 18 times 212 = 38Gt C of emissions to get 1ppm ofatmospheric concentration
Recall the carbon cycle equation from our model
P2 = ρ0E + P1
We have just calculated that ρ0 = 138 = 026ppm C (or CO2 )
Gt C
What is ρ0 if we denominate emissions in terms of CO2
Atmospheric carbon cycle
Atmospheric CO2 cycle data IV
In Hansenrsquos graph the fraction of emissions retained in theatmosphere is CONSTANT as emissions are increasing This isthought to reflect increased absorbtion by plant lsquocarbonfertilizationrsquo or increased lsquonet primary productivityrsquo
In AOGCMrsquos the carbon cycle is modelled very carefully We reallywant to deal with the possibility that absorbtion varies withtemperature or CO2 (it probably does) and there is a lot ofuncertainty about this relationship
Consumption and emissions
Emissions for particular activities I
CO2 from gasoline 23 kgliter = 194 poundsgallon So1000 kg of CO2 emission results from 435 liters or 114gallons of gas (about 1 not burned is mostly N2O so CO2e ishigher)
CO2 from diesel 27 kgliter = 222 poundsgallon 1000 kg ofCO2 emission results from 370 liters or 97 gallons of dieselhttpwwwepagovotaqclimate420f05001htmcalculating
BBQ propane tank about 18 pounds propane = 24kg = 53 lbCO2 (NB Gasoline weighs 63 poundsgallon so 18 poundsof gas gives about 54 pounds CO2 Propane has morehydrogen per carbon atom than gasoline)
Consumption and emissions
Emissions for particular activities II
CO2 sequestration by 1 acre 90 year old pine forest inSoutheastern US is about 100 tons C about 1 tonacreyearSo burning this acre releases about 100 tons C or 367 tonsCO2 httpwwwepagovsequestrationfaqhtml For tropical forests about 18times as much not reliable source
CO2 from coal about 200 tons CO2 per ton (a lot of the stuffin coal is not burned ndash I think) or 2100lb CO2 per 1000 KWHfrom non-baseload coal burning electricity generation CO2eis higher Baseload will usually be lower (often nuclear orhydro) httpwwweiagovtoolsfaqsfaqcfmid=74ampt=11
Consumption and emissions
Emissions for particular activities III
For natural gas about 1200lb CO2 per 1000 KWH Sofracking is fantastic unless too much methane leaks beforeitrsquos burnt With 1 ton of methane worth 23 tons of CO2 about43 leakage makes coal and natural gas even (unless thereis methane leakage from coal mines) The rate of leakage iscurrently contested EPA current estimate is about 06 but05 is probably better (Allen et al PNAS 2013)
For reference Avg household in RI = 500KWHmo Avghousehold in TX = 1000KWHmohttpswwweiagovtoolsfaqsfaqcfmid=97ampt=3 (Feb 2016) Or averagehousehold in Providence sim 8000kwhyear in 2001 Dallas sim18500kwhyear (Glaeser and Kahn JUE 2010)
Consumption and emissions
Emissions for particular activities IV
For thinking about fracking also consider the following
Consumption and emissions
Global emissions per unit of consumption ca 2013
Using these sorts of particular numbers together with informationabout aggregate consumption one can calculate world emissions
Global annual emissions ca 2013 are about 49Gt CO2e or49 times 12
44 sim 133 Gt C (more on this later)
World GDP in 2013 is about 77 trillion USD (NB this is W inour model)
Dividingwe have 133times109 tons C77times1012000USD = 133
7700ton CUSD sim 017 kg C
USD (1 ton= 1000 kg) Multiply by 4412 for CO2 instead of C
Recall the third equation from our global warming model
E = (1 minus ρ4MW
)(ρ5(c1 + I)) (7)
Wersquove just calculated ρ5 Why is this sloppy
Consumption and emissions
Emissions per unit of consumption by countryItrsquos also interesting to look at the country by countrybreakdown(ca 2004) The US and Canada make a lot of stuffper ton of emissions
IPCC 2007 Mitigation fig SPM3b
What if China and Africa made same output at USCAemission rates This is why technology transfer is importantCompare 068 kg CO2e per dollar ca 2004 to my calculationof 017 kg C per dollar 2013 How important is technicalprogress
Consumption and emissions
Technological progress I
httpwww3epagovclimatechangescienceindicatorsghgus-ghg-emissionshtml January 2016
Consumption and emissions
Technological progress II
Nordhaus does this calculation every year country by country
Russia
India
World
EU
US
China
Consumption and emissions
Emissions - Summary
Wersquove now calculated ρ5 emissions per GDP at about 017kgC per dollar ca 2013Looking at the data a little more carefully highlights twodeficiencies on our model
Technological progress is at work so this ratio changes overtimeThere are huge difference across places in this ratio
This highlights the importance of technological progress andtechnology transfer in solving the problem of climate change
Wersquoll address this when we get to the Nordhaus model
Emissions
Emissions trends and levels
Recall
maxIM
u(c1 c2) (8)
st W = c1 + I + M (9)
c2 = (1 + r)I minus γ(T2 minus T1)I (10)
E = (1 minus ρ4MW
)(ρ5(c1 + I)) (11)
P2 = ρ0E + P1 (12)
T2 = ρ1(P2 minus P1) + T1 (13)
Wersquove filled in a bit more The next step is to look at E This meanslooking at trends and levels in CO2 emissions
Emissions
CO2e 1970-2010
IPCC 2013 WG3 fig TS1
Right panel gives confidence bounds for 2010 49Gt CO2e in 2010
Emissions
CO2 by purpose and country income 1750-2010
IPCC 2013 WG3 fig TS2
Emissions
Hansenrsquos version of the same thing
Flow StockHansen 2009 fig 27
Contributions to stock and flow are very different At thenegotiating table developing countries want the right to emit sinceeveryone else had their turn
Emissions
2010 CO2e by purpose
IPCC 2013 WG3 fig TS3
Emissions
2010 CO2e by purpose and country income
IPCC 2013 WG3 fig TS3
Emissions
US 1990-2017 CO2e
ES-4 Inventory of US Greenhouse Gas Emissions and Sinks 1990ndash2017
ES2 Recent Trends in US Greenhouse Gas Emissions and Sinks
In 2017 total gross US greenhouse gas emissions were 64567 MMT or million metric tons of carbon dioxide (CO2) Eq11 Total US emissions have increased by 13 percent from 1990 to 2017 and emissions decreased from 2016 to 2017 by 05 percent (355 MMT CO2 Eq) The decrease in total greenhouse gas emissions between 2016 and 2017 was driven in part by a decrease in CO2 emissions from fossil fuel combustion The decrease in CO2 emissions from fossil fuel combustion was a result of multiple factors including a continued shift from coal to natural gas and increased use of renewable energy in the electric power sector and milder weather that contributed to less overall electricity use
Relative to 1990 the baseline for this Inventory gross emissions in 2017 are higher by 13 percent down from a high of 157 percent above 1990 levels in 2007 Overall net emissions in 2017 were 130 percent below 2005 levels as shown in Table ES-2 Figure ES-1 through Figure ES-3 illustrate the overall trends in total US emissions by gas annual changes and absolute change since 1990 and Table ES-2 provides a detailed summary of gross US greenhouse gas emissions and sinks for 1990 through 2017 Note unless otherwise stated all tables and figures provide total gross emissions and exclude the greenhouse gas fluxes from the Land Use Land-Use Change and Forestry (LULUCF) sector (see Section ES3 Overview of Sector Emissions and Trends)
Figure ES-1 Gross US Greenhouse Gas Emissions by Gas (MMT CO2 Eq)
11 The gross emissions total presented in this report for the United States excludes emissions and removals from Land Use Land-Use Change and Forestry (LULUCF) The net emissions total presented in this report for the United States includes emissions and removals from LULUCF
httpswwwepagovsitesproductionfiles2019-04documentsus-ghg-inventory-2019-main-textpdf September 2019
This reflects fracking recession technical progress off-shoring ofmanufacturing Emissions are likely up since 2017
Emissions
Emissions per person
Itrsquos also interesting to look at the country by country breakdown interms of emissions per capita
IPCC 2007 Mitigation fig SPM3a
As of 2012 US had 454 tons C person and for India this numberwas 046 China was 18(httpcdiacornlgovtrendsemistop2011cap)
Emissions
The problem of stabilizing atmospheric CO2Emissions are about 13Gt C per year
The ocean and biosphere absorb about 45 of emissions (sofar)
This means the ocean and biosphere absorb 13 times 045 asymp 6GtC per year
As a rough guess this means that reducing emissions to 6GtC per year will stabilize atmospheric CO2 (but not climate)
This involves a 55 decrease For an average American thismeans this means reducing emissions from 45 tons per yearto about 20 if US share of total emissions stays constant Ifemissions are allocated equally to each of the worldrsquos 74bpeople then each of us gets 6Gt C 74b people or about 08ton This is an 82 decrease for the average American It isalso about the twice the level of the average Indian and halfthat of the average Chinese
Emissions
Summary
2013 emissions of CO2e were about 49Gt Of this 35Gt wasCO2 and of this about 30Gt from fossil fuels and 5Gt fromland use change and agriculture This is E in our model
Emission are growing rapidly about 2year between 2000and 2010 1970 CO2e was 30Gt
2010 CO2e 14 transport 18 buildings 21 industry 24AFOLU We could use this to calculate refinements of ρ5
The countries responsible for most of the stock are not thecountries responsible for most of the flow
Per capita emissions vary by a factor of about 10 between richand poor countries
There has been a decline in US emissions since 2008 due tofracking recession technical progress off shoring
Peak oil
Will we run out of fossil fuel INot soon enough to matter
0
200
400
600
800
Estimated Reserves
Emissions to Date
Gig
aton
s C
arbo
n
Oil Gas Coal Land Use
EIA
IPCCEIA
IPCC
100
200
300
Em
itted
CO
2 (p
pm)
0
200
400
600
800
We have oceans of coal and lots of oil and these figures predateUS fracking
Peak oil
Will we run out of fossil fuel II
Conclusion
Conclusion I
Here is where we stand with our model
maxIM
u(c1 c2) (14)
st W = c1 + I + M (15)
c2 = (1 + r)I minus γ(T2 minus T1)I (16)
E = (1 minus ρ4MW
)(ρ5(c1 + I)) (17)
P2 = ρ0E + P1 (18)
T2 = ρ1(P2 minus P1) + T1 (19)
We have enough pieces filled in to permit you to calculate theimpact on future climate of particular sorts of current consumptioneg burning a tank of propane on your bbq Wersquoll next start
Conclusion
Conclusion II
thinking about the effect of climate change on production γthough wersquoll make an aside to talk about measurement error first
Conclusion
Conclusion III
Each ppm of atmospheric CO2 corresponds to about 212 Gt C
and 778 Gt of CO2 Pay attention to the units people use
Not all gases are equal in their green house potential CO2 ismost common and most important but other gases are moreimportant per unit of emissions
Over the past 50 years about 55 of each emitted Gt of C
has stayed in the atmosphere The rest has been absorbed byland or oceans Thus it takes about 38 Gt C per 1ppm ofatmospheric CO2
Conclusion
Conclusion IV
Emissions are about 13Gt C for 2013 The rate at whichatmospheric CO2 is increasing has risen from about 1ppmyr1960s to 2ppm for 2000rsquos Since there is lots of fuel weshould expect atmospheric CO2 to continue to increase and atan increasing rate lsquobusiness as usual scenarios call foratmospheric CO2e gt 800 within 100 years
Not all countries are the same They are responsible fordifferent shares have different per capita emissions useemission more or less efficiently and are responsible fordifferent shares of historical emissions These factors are veryimportant obstacles to international agreements and alsosuggest the need for a richer model
Conclusion
Conclusion V
Steady state CO2 emissions are probably very small Sternsuggests less than 13 of current Our calculations suggest(1-055)=45
Review
The next to last equation is a model of the atmosphericcarbon cycle We discussed our endowment and projectedatmospheric CO2 last time
This time we want to talk about Emissions E ρ0 therelationship between emissions and concentration and ρ5 therelationship between consumption and emissions
Carbon cycle
Emissions and concentration of CO2
What is the relationship between emissions and atmosphericconcentration
Each ppm of atmospheric concentration is about 212 Gt C This is a standard conversion factor both IPCC and Hansenuse it (gigatons = billion tons)A molecule of CO2 is about 4412 as heavy as a molecule ofC Thus each ppm of atmospheric concentration of C isabout 212GtC times (4412) = 777GtCO2Hansen and IPCC 20072013 Physical Science Basismeasure emissions in terms of Gt C but Stern IPCC20072013 Mitigation of Climate Change measure emissionsin terms of Gt CO2 Social scientists often measure Green house gases in termsof CO2 equivalent emissions
In July 2019 the concentration of CO2 in the atmosphere was 412ppm This is equal to 873 Gt C and 3201 Gt CO2
Carbon cycle
CO2 is not the only GHG I
From Stern 2008 table 81
Carbon cycle
CO2 is not the only GHG II
July 2019 concentration of CO2 was 412 ppm Using thenumbers above current CO2e is 412077 = 535CO2e
From the forcing tables we see that non-CO2 is has about halfthe forcing capacity of CO2 However non-CO2 is lesspersistent so it makes a smaller total contribution to warmingthan this share suggests
Carbon cycle
What is lsquoGlobal Warming Potentialrsquo I
We would like to calculate the rate at which we are willing totrade CH4 for CO2 To do this define αt as the change inradiative forcing from one unit of concentration of the gas at t
ieWm2
PPM Define GWP as warming potential relative to CO2
GWP(CH4 ) =
int T0 αCH4 (t)dtint T0 αCO2 (t)dt
Example suppose t = 1 2 3 and for CO2 (αCO2 (1) αCO2 (2) αCO2 (3)) = (1 1 1) and for CH4 (αCH4 (1) αCH4 (2) αCH4 (3)) = (2 0 0)Then GWP(CH4 ) = 2+0+0
1+1+1
Carbon cycle
What is lsquoGlobal Warming Potentialrsquo II
Issues
T is completely arbitrary GWP of CH4 for T = 20 100 500 isabout 63 21 9We care about damage not radiative forcing (see Schmalensee The
Energy Journal (1993)) To see this considerIf we anticipate that the world will end in 20 years then neitherCO2 nor CH4 is very harmful but CH4 causes a lot morewarming over that time than CO2If we plan to spend the next 20 years as we do now but then topermanently convert to an economy based on penguinfarming then CH4 emissions now are not very harmful but CO2is (because it is persistent)
We canrsquot really assign relative values to CO2 and CH4 until wesolve for the whole optimal path of emissions for both gasesso any definition of GWP is going to be unsatisfactory
Carbon cycle
Units
Stern 2007 p193 gives CO2e emissions for 2000 as 42Gt CO2e Hansen has 85 Gt C from fossil fuelCan we reconcile these numbers(Yes)
About 77 of CO2e is CO2
About 18 of CO2 is non fossil fuel (more on this later)
Stern reports CO2 Hansen C
so Sternrsquos 42 Gt CO2e becomes42 times (77(1 minus 18))times (1244) = 72 Gt of atmospheric C It would be closer but Stern uses 2000 numbers and Hansenrsquos 85is for about 2008
Atmospheric carbon cycle
Carbon cycle
Carbon is cycled back and forth between the atmosphere oceanand land by biological and chemical processes This means thatemissions donrsquot translate immediately into atmosphericconcentrations Stocksannual flows of C (not CO2 ) are
Atmosphere 800+45Gt
Ocean 40000+3Gt
Volcanos ndash-01Gt
Forests 600-16 Gt
Fossil fuels 5000-85
Sediments ndash-1Gt
Atmospheric carbon cycle
Fossil fuel emissions and deforestation put about 10Gt C in theatmosphere (ca 2007) Atmospheric C increased by about 45GtAbout 3Gt are absorbed by the ocean The remaining 25Gt arethought to be absorbed by plants (NB old numbers to go withfigure) Numbers from Hansen 2009 about the same as in Jacob 1999
Black = natural Red=Anthropogenic AOGCM models of carbon cycle are complicated IPCC 2007 Physical Science basis
figure 73
Atmospheric carbon cycle
Atmospheric CO2 cycle data I
Another way to see this is to look at the relationship betweenemissions and concentration directly
Calculate annual change in C ppm from Mauna Loa (eg)
Calculate annual emissions using emissions rates andconsumption data (more below)
Calculate ratio ∆CO2ppmFossil Fuel emissions = concentration yield of
emissions
Atmospheric carbon cycle
Atmospheric CO2 cycle data II
1950 1960 1970 1980 1990 2000 2010 0
2
4
6
8
10
Global Fossil Fuel CO2 EmissionsCO2 Airborne Fraction (7minusyear mean)
Em
issi
ons
(Gig
aton
s C
yea
r)
0
20
40
60
80
100
Air
born
e Fr
actio
n (
)
Hansen 2009 figure 16
Atmospheric carbon cycle
Atmospheric CO2 cycle data III
So concentration yield of emissions is about 55 Thus
(1055)= 18 Gt C emissions gives 1 Gt ton of atmospheric C
212 Gt atmospheric C to gives 1ppm atmospheric C (or CO2 )
Multiplying 18 times 212 = 38Gt C of emissions to get 1ppm ofatmospheric concentration
Recall the carbon cycle equation from our model
P2 = ρ0E + P1
We have just calculated that ρ0 = 138 = 026ppm C (or CO2 )
Gt C
What is ρ0 if we denominate emissions in terms of CO2
Atmospheric carbon cycle
Atmospheric CO2 cycle data IV
In Hansenrsquos graph the fraction of emissions retained in theatmosphere is CONSTANT as emissions are increasing This isthought to reflect increased absorbtion by plant lsquocarbonfertilizationrsquo or increased lsquonet primary productivityrsquo
In AOGCMrsquos the carbon cycle is modelled very carefully We reallywant to deal with the possibility that absorbtion varies withtemperature or CO2 (it probably does) and there is a lot ofuncertainty about this relationship
Consumption and emissions
Emissions for particular activities I
CO2 from gasoline 23 kgliter = 194 poundsgallon So1000 kg of CO2 emission results from 435 liters or 114gallons of gas (about 1 not burned is mostly N2O so CO2e ishigher)
CO2 from diesel 27 kgliter = 222 poundsgallon 1000 kg ofCO2 emission results from 370 liters or 97 gallons of dieselhttpwwwepagovotaqclimate420f05001htmcalculating
BBQ propane tank about 18 pounds propane = 24kg = 53 lbCO2 (NB Gasoline weighs 63 poundsgallon so 18 poundsof gas gives about 54 pounds CO2 Propane has morehydrogen per carbon atom than gasoline)
Consumption and emissions
Emissions for particular activities II
CO2 sequestration by 1 acre 90 year old pine forest inSoutheastern US is about 100 tons C about 1 tonacreyearSo burning this acre releases about 100 tons C or 367 tonsCO2 httpwwwepagovsequestrationfaqhtml For tropical forests about 18times as much not reliable source
CO2 from coal about 200 tons CO2 per ton (a lot of the stuffin coal is not burned ndash I think) or 2100lb CO2 per 1000 KWHfrom non-baseload coal burning electricity generation CO2eis higher Baseload will usually be lower (often nuclear orhydro) httpwwweiagovtoolsfaqsfaqcfmid=74ampt=11
Consumption and emissions
Emissions for particular activities III
For natural gas about 1200lb CO2 per 1000 KWH Sofracking is fantastic unless too much methane leaks beforeitrsquos burnt With 1 ton of methane worth 23 tons of CO2 about43 leakage makes coal and natural gas even (unless thereis methane leakage from coal mines) The rate of leakage iscurrently contested EPA current estimate is about 06 but05 is probably better (Allen et al PNAS 2013)
For reference Avg household in RI = 500KWHmo Avghousehold in TX = 1000KWHmohttpswwweiagovtoolsfaqsfaqcfmid=97ampt=3 (Feb 2016) Or averagehousehold in Providence sim 8000kwhyear in 2001 Dallas sim18500kwhyear (Glaeser and Kahn JUE 2010)
Consumption and emissions
Emissions for particular activities IV
For thinking about fracking also consider the following
Consumption and emissions
Global emissions per unit of consumption ca 2013
Using these sorts of particular numbers together with informationabout aggregate consumption one can calculate world emissions
Global annual emissions ca 2013 are about 49Gt CO2e or49 times 12
44 sim 133 Gt C (more on this later)
World GDP in 2013 is about 77 trillion USD (NB this is W inour model)
Dividingwe have 133times109 tons C77times1012000USD = 133
7700ton CUSD sim 017 kg C
USD (1 ton= 1000 kg) Multiply by 4412 for CO2 instead of C
Recall the third equation from our global warming model
E = (1 minus ρ4MW
)(ρ5(c1 + I)) (7)
Wersquove just calculated ρ5 Why is this sloppy
Consumption and emissions
Emissions per unit of consumption by countryItrsquos also interesting to look at the country by countrybreakdown(ca 2004) The US and Canada make a lot of stuffper ton of emissions
IPCC 2007 Mitigation fig SPM3b
What if China and Africa made same output at USCAemission rates This is why technology transfer is importantCompare 068 kg CO2e per dollar ca 2004 to my calculationof 017 kg C per dollar 2013 How important is technicalprogress
Consumption and emissions
Technological progress I
httpwww3epagovclimatechangescienceindicatorsghgus-ghg-emissionshtml January 2016
Consumption and emissions
Technological progress II
Nordhaus does this calculation every year country by country
Russia
India
World
EU
US
China
Consumption and emissions
Emissions - Summary
Wersquove now calculated ρ5 emissions per GDP at about 017kgC per dollar ca 2013Looking at the data a little more carefully highlights twodeficiencies on our model
Technological progress is at work so this ratio changes overtimeThere are huge difference across places in this ratio
This highlights the importance of technological progress andtechnology transfer in solving the problem of climate change
Wersquoll address this when we get to the Nordhaus model
Emissions
Emissions trends and levels
Recall
maxIM
u(c1 c2) (8)
st W = c1 + I + M (9)
c2 = (1 + r)I minus γ(T2 minus T1)I (10)
E = (1 minus ρ4MW
)(ρ5(c1 + I)) (11)
P2 = ρ0E + P1 (12)
T2 = ρ1(P2 minus P1) + T1 (13)
Wersquove filled in a bit more The next step is to look at E This meanslooking at trends and levels in CO2 emissions
Emissions
CO2e 1970-2010
IPCC 2013 WG3 fig TS1
Right panel gives confidence bounds for 2010 49Gt CO2e in 2010
Emissions
CO2 by purpose and country income 1750-2010
IPCC 2013 WG3 fig TS2
Emissions
Hansenrsquos version of the same thing
Flow StockHansen 2009 fig 27
Contributions to stock and flow are very different At thenegotiating table developing countries want the right to emit sinceeveryone else had their turn
Emissions
2010 CO2e by purpose
IPCC 2013 WG3 fig TS3
Emissions
2010 CO2e by purpose and country income
IPCC 2013 WG3 fig TS3
Emissions
US 1990-2017 CO2e
ES-4 Inventory of US Greenhouse Gas Emissions and Sinks 1990ndash2017
ES2 Recent Trends in US Greenhouse Gas Emissions and Sinks
In 2017 total gross US greenhouse gas emissions were 64567 MMT or million metric tons of carbon dioxide (CO2) Eq11 Total US emissions have increased by 13 percent from 1990 to 2017 and emissions decreased from 2016 to 2017 by 05 percent (355 MMT CO2 Eq) The decrease in total greenhouse gas emissions between 2016 and 2017 was driven in part by a decrease in CO2 emissions from fossil fuel combustion The decrease in CO2 emissions from fossil fuel combustion was a result of multiple factors including a continued shift from coal to natural gas and increased use of renewable energy in the electric power sector and milder weather that contributed to less overall electricity use
Relative to 1990 the baseline for this Inventory gross emissions in 2017 are higher by 13 percent down from a high of 157 percent above 1990 levels in 2007 Overall net emissions in 2017 were 130 percent below 2005 levels as shown in Table ES-2 Figure ES-1 through Figure ES-3 illustrate the overall trends in total US emissions by gas annual changes and absolute change since 1990 and Table ES-2 provides a detailed summary of gross US greenhouse gas emissions and sinks for 1990 through 2017 Note unless otherwise stated all tables and figures provide total gross emissions and exclude the greenhouse gas fluxes from the Land Use Land-Use Change and Forestry (LULUCF) sector (see Section ES3 Overview of Sector Emissions and Trends)
Figure ES-1 Gross US Greenhouse Gas Emissions by Gas (MMT CO2 Eq)
11 The gross emissions total presented in this report for the United States excludes emissions and removals from Land Use Land-Use Change and Forestry (LULUCF) The net emissions total presented in this report for the United States includes emissions and removals from LULUCF
httpswwwepagovsitesproductionfiles2019-04documentsus-ghg-inventory-2019-main-textpdf September 2019
This reflects fracking recession technical progress off-shoring ofmanufacturing Emissions are likely up since 2017
Emissions
Emissions per person
Itrsquos also interesting to look at the country by country breakdown interms of emissions per capita
IPCC 2007 Mitigation fig SPM3a
As of 2012 US had 454 tons C person and for India this numberwas 046 China was 18(httpcdiacornlgovtrendsemistop2011cap)
Emissions
The problem of stabilizing atmospheric CO2Emissions are about 13Gt C per year
The ocean and biosphere absorb about 45 of emissions (sofar)
This means the ocean and biosphere absorb 13 times 045 asymp 6GtC per year
As a rough guess this means that reducing emissions to 6GtC per year will stabilize atmospheric CO2 (but not climate)
This involves a 55 decrease For an average American thismeans this means reducing emissions from 45 tons per yearto about 20 if US share of total emissions stays constant Ifemissions are allocated equally to each of the worldrsquos 74bpeople then each of us gets 6Gt C 74b people or about 08ton This is an 82 decrease for the average American It isalso about the twice the level of the average Indian and halfthat of the average Chinese
Emissions
Summary
2013 emissions of CO2e were about 49Gt Of this 35Gt wasCO2 and of this about 30Gt from fossil fuels and 5Gt fromland use change and agriculture This is E in our model
Emission are growing rapidly about 2year between 2000and 2010 1970 CO2e was 30Gt
2010 CO2e 14 transport 18 buildings 21 industry 24AFOLU We could use this to calculate refinements of ρ5
The countries responsible for most of the stock are not thecountries responsible for most of the flow
Per capita emissions vary by a factor of about 10 between richand poor countries
There has been a decline in US emissions since 2008 due tofracking recession technical progress off shoring
Peak oil
Will we run out of fossil fuel INot soon enough to matter
0
200
400
600
800
Estimated Reserves
Emissions to Date
Gig
aton
s C
arbo
n
Oil Gas Coal Land Use
EIA
IPCCEIA
IPCC
100
200
300
Em
itted
CO
2 (p
pm)
0
200
400
600
800
We have oceans of coal and lots of oil and these figures predateUS fracking
Peak oil
Will we run out of fossil fuel II
Conclusion
Conclusion I
Here is where we stand with our model
maxIM
u(c1 c2) (14)
st W = c1 + I + M (15)
c2 = (1 + r)I minus γ(T2 minus T1)I (16)
E = (1 minus ρ4MW
)(ρ5(c1 + I)) (17)
P2 = ρ0E + P1 (18)
T2 = ρ1(P2 minus P1) + T1 (19)
We have enough pieces filled in to permit you to calculate theimpact on future climate of particular sorts of current consumptioneg burning a tank of propane on your bbq Wersquoll next start
Conclusion
Conclusion II
thinking about the effect of climate change on production γthough wersquoll make an aside to talk about measurement error first
Conclusion
Conclusion III
Each ppm of atmospheric CO2 corresponds to about 212 Gt C
and 778 Gt of CO2 Pay attention to the units people use
Not all gases are equal in their green house potential CO2 ismost common and most important but other gases are moreimportant per unit of emissions
Over the past 50 years about 55 of each emitted Gt of C
has stayed in the atmosphere The rest has been absorbed byland or oceans Thus it takes about 38 Gt C per 1ppm ofatmospheric CO2
Conclusion
Conclusion IV
Emissions are about 13Gt C for 2013 The rate at whichatmospheric CO2 is increasing has risen from about 1ppmyr1960s to 2ppm for 2000rsquos Since there is lots of fuel weshould expect atmospheric CO2 to continue to increase and atan increasing rate lsquobusiness as usual scenarios call foratmospheric CO2e gt 800 within 100 years
Not all countries are the same They are responsible fordifferent shares have different per capita emissions useemission more or less efficiently and are responsible fordifferent shares of historical emissions These factors are veryimportant obstacles to international agreements and alsosuggest the need for a richer model
Conclusion
Conclusion V
Steady state CO2 emissions are probably very small Sternsuggests less than 13 of current Our calculations suggest(1-055)=45
Carbon cycle
Emissions and concentration of CO2
What is the relationship between emissions and atmosphericconcentration
Each ppm of atmospheric concentration is about 212 Gt C This is a standard conversion factor both IPCC and Hansenuse it (gigatons = billion tons)A molecule of CO2 is about 4412 as heavy as a molecule ofC Thus each ppm of atmospheric concentration of C isabout 212GtC times (4412) = 777GtCO2Hansen and IPCC 20072013 Physical Science Basismeasure emissions in terms of Gt C but Stern IPCC20072013 Mitigation of Climate Change measure emissionsin terms of Gt CO2 Social scientists often measure Green house gases in termsof CO2 equivalent emissions
In July 2019 the concentration of CO2 in the atmosphere was 412ppm This is equal to 873 Gt C and 3201 Gt CO2
Carbon cycle
CO2 is not the only GHG I
From Stern 2008 table 81
Carbon cycle
CO2 is not the only GHG II
July 2019 concentration of CO2 was 412 ppm Using thenumbers above current CO2e is 412077 = 535CO2e
From the forcing tables we see that non-CO2 is has about halfthe forcing capacity of CO2 However non-CO2 is lesspersistent so it makes a smaller total contribution to warmingthan this share suggests
Carbon cycle
What is lsquoGlobal Warming Potentialrsquo I
We would like to calculate the rate at which we are willing totrade CH4 for CO2 To do this define αt as the change inradiative forcing from one unit of concentration of the gas at t
ieWm2
PPM Define GWP as warming potential relative to CO2
GWP(CH4 ) =
int T0 αCH4 (t)dtint T0 αCO2 (t)dt
Example suppose t = 1 2 3 and for CO2 (αCO2 (1) αCO2 (2) αCO2 (3)) = (1 1 1) and for CH4 (αCH4 (1) αCH4 (2) αCH4 (3)) = (2 0 0)Then GWP(CH4 ) = 2+0+0
1+1+1
Carbon cycle
What is lsquoGlobal Warming Potentialrsquo II
Issues
T is completely arbitrary GWP of CH4 for T = 20 100 500 isabout 63 21 9We care about damage not radiative forcing (see Schmalensee The
Energy Journal (1993)) To see this considerIf we anticipate that the world will end in 20 years then neitherCO2 nor CH4 is very harmful but CH4 causes a lot morewarming over that time than CO2If we plan to spend the next 20 years as we do now but then topermanently convert to an economy based on penguinfarming then CH4 emissions now are not very harmful but CO2is (because it is persistent)
We canrsquot really assign relative values to CO2 and CH4 until wesolve for the whole optimal path of emissions for both gasesso any definition of GWP is going to be unsatisfactory
Carbon cycle
Units
Stern 2007 p193 gives CO2e emissions for 2000 as 42Gt CO2e Hansen has 85 Gt C from fossil fuelCan we reconcile these numbers(Yes)
About 77 of CO2e is CO2
About 18 of CO2 is non fossil fuel (more on this later)
Stern reports CO2 Hansen C
so Sternrsquos 42 Gt CO2e becomes42 times (77(1 minus 18))times (1244) = 72 Gt of atmospheric C It would be closer but Stern uses 2000 numbers and Hansenrsquos 85is for about 2008
Atmospheric carbon cycle
Carbon cycle
Carbon is cycled back and forth between the atmosphere oceanand land by biological and chemical processes This means thatemissions donrsquot translate immediately into atmosphericconcentrations Stocksannual flows of C (not CO2 ) are
Atmosphere 800+45Gt
Ocean 40000+3Gt
Volcanos ndash-01Gt
Forests 600-16 Gt
Fossil fuels 5000-85
Sediments ndash-1Gt
Atmospheric carbon cycle
Fossil fuel emissions and deforestation put about 10Gt C in theatmosphere (ca 2007) Atmospheric C increased by about 45GtAbout 3Gt are absorbed by the ocean The remaining 25Gt arethought to be absorbed by plants (NB old numbers to go withfigure) Numbers from Hansen 2009 about the same as in Jacob 1999
Black = natural Red=Anthropogenic AOGCM models of carbon cycle are complicated IPCC 2007 Physical Science basis
figure 73
Atmospheric carbon cycle
Atmospheric CO2 cycle data I
Another way to see this is to look at the relationship betweenemissions and concentration directly
Calculate annual change in C ppm from Mauna Loa (eg)
Calculate annual emissions using emissions rates andconsumption data (more below)
Calculate ratio ∆CO2ppmFossil Fuel emissions = concentration yield of
emissions
Atmospheric carbon cycle
Atmospheric CO2 cycle data II
1950 1960 1970 1980 1990 2000 2010 0
2
4
6
8
10
Global Fossil Fuel CO2 EmissionsCO2 Airborne Fraction (7minusyear mean)
Em
issi
ons
(Gig
aton
s C
yea
r)
0
20
40
60
80
100
Air
born
e Fr
actio
n (
)
Hansen 2009 figure 16
Atmospheric carbon cycle
Atmospheric CO2 cycle data III
So concentration yield of emissions is about 55 Thus
(1055)= 18 Gt C emissions gives 1 Gt ton of atmospheric C
212 Gt atmospheric C to gives 1ppm atmospheric C (or CO2 )
Multiplying 18 times 212 = 38Gt C of emissions to get 1ppm ofatmospheric concentration
Recall the carbon cycle equation from our model
P2 = ρ0E + P1
We have just calculated that ρ0 = 138 = 026ppm C (or CO2 )
Gt C
What is ρ0 if we denominate emissions in terms of CO2
Atmospheric carbon cycle
Atmospheric CO2 cycle data IV
In Hansenrsquos graph the fraction of emissions retained in theatmosphere is CONSTANT as emissions are increasing This isthought to reflect increased absorbtion by plant lsquocarbonfertilizationrsquo or increased lsquonet primary productivityrsquo
In AOGCMrsquos the carbon cycle is modelled very carefully We reallywant to deal with the possibility that absorbtion varies withtemperature or CO2 (it probably does) and there is a lot ofuncertainty about this relationship
Consumption and emissions
Emissions for particular activities I
CO2 from gasoline 23 kgliter = 194 poundsgallon So1000 kg of CO2 emission results from 435 liters or 114gallons of gas (about 1 not burned is mostly N2O so CO2e ishigher)
CO2 from diesel 27 kgliter = 222 poundsgallon 1000 kg ofCO2 emission results from 370 liters or 97 gallons of dieselhttpwwwepagovotaqclimate420f05001htmcalculating
BBQ propane tank about 18 pounds propane = 24kg = 53 lbCO2 (NB Gasoline weighs 63 poundsgallon so 18 poundsof gas gives about 54 pounds CO2 Propane has morehydrogen per carbon atom than gasoline)
Consumption and emissions
Emissions for particular activities II
CO2 sequestration by 1 acre 90 year old pine forest inSoutheastern US is about 100 tons C about 1 tonacreyearSo burning this acre releases about 100 tons C or 367 tonsCO2 httpwwwepagovsequestrationfaqhtml For tropical forests about 18times as much not reliable source
CO2 from coal about 200 tons CO2 per ton (a lot of the stuffin coal is not burned ndash I think) or 2100lb CO2 per 1000 KWHfrom non-baseload coal burning electricity generation CO2eis higher Baseload will usually be lower (often nuclear orhydro) httpwwweiagovtoolsfaqsfaqcfmid=74ampt=11
Consumption and emissions
Emissions for particular activities III
For natural gas about 1200lb CO2 per 1000 KWH Sofracking is fantastic unless too much methane leaks beforeitrsquos burnt With 1 ton of methane worth 23 tons of CO2 about43 leakage makes coal and natural gas even (unless thereis methane leakage from coal mines) The rate of leakage iscurrently contested EPA current estimate is about 06 but05 is probably better (Allen et al PNAS 2013)
For reference Avg household in RI = 500KWHmo Avghousehold in TX = 1000KWHmohttpswwweiagovtoolsfaqsfaqcfmid=97ampt=3 (Feb 2016) Or averagehousehold in Providence sim 8000kwhyear in 2001 Dallas sim18500kwhyear (Glaeser and Kahn JUE 2010)
Consumption and emissions
Emissions for particular activities IV
For thinking about fracking also consider the following
Consumption and emissions
Global emissions per unit of consumption ca 2013
Using these sorts of particular numbers together with informationabout aggregate consumption one can calculate world emissions
Global annual emissions ca 2013 are about 49Gt CO2e or49 times 12
44 sim 133 Gt C (more on this later)
World GDP in 2013 is about 77 trillion USD (NB this is W inour model)
Dividingwe have 133times109 tons C77times1012000USD = 133
7700ton CUSD sim 017 kg C
USD (1 ton= 1000 kg) Multiply by 4412 for CO2 instead of C
Recall the third equation from our global warming model
E = (1 minus ρ4MW
)(ρ5(c1 + I)) (7)
Wersquove just calculated ρ5 Why is this sloppy
Consumption and emissions
Emissions per unit of consumption by countryItrsquos also interesting to look at the country by countrybreakdown(ca 2004) The US and Canada make a lot of stuffper ton of emissions
IPCC 2007 Mitigation fig SPM3b
What if China and Africa made same output at USCAemission rates This is why technology transfer is importantCompare 068 kg CO2e per dollar ca 2004 to my calculationof 017 kg C per dollar 2013 How important is technicalprogress
Consumption and emissions
Technological progress I
httpwww3epagovclimatechangescienceindicatorsghgus-ghg-emissionshtml January 2016
Consumption and emissions
Technological progress II
Nordhaus does this calculation every year country by country
Russia
India
World
EU
US
China
Consumption and emissions
Emissions - Summary
Wersquove now calculated ρ5 emissions per GDP at about 017kgC per dollar ca 2013Looking at the data a little more carefully highlights twodeficiencies on our model
Technological progress is at work so this ratio changes overtimeThere are huge difference across places in this ratio
This highlights the importance of technological progress andtechnology transfer in solving the problem of climate change
Wersquoll address this when we get to the Nordhaus model
Emissions
Emissions trends and levels
Recall
maxIM
u(c1 c2) (8)
st W = c1 + I + M (9)
c2 = (1 + r)I minus γ(T2 minus T1)I (10)
E = (1 minus ρ4MW
)(ρ5(c1 + I)) (11)
P2 = ρ0E + P1 (12)
T2 = ρ1(P2 minus P1) + T1 (13)
Wersquove filled in a bit more The next step is to look at E This meanslooking at trends and levels in CO2 emissions
Emissions
CO2e 1970-2010
IPCC 2013 WG3 fig TS1
Right panel gives confidence bounds for 2010 49Gt CO2e in 2010
Emissions
CO2 by purpose and country income 1750-2010
IPCC 2013 WG3 fig TS2
Emissions
Hansenrsquos version of the same thing
Flow StockHansen 2009 fig 27
Contributions to stock and flow are very different At thenegotiating table developing countries want the right to emit sinceeveryone else had their turn
Emissions
2010 CO2e by purpose
IPCC 2013 WG3 fig TS3
Emissions
2010 CO2e by purpose and country income
IPCC 2013 WG3 fig TS3
Emissions
US 1990-2017 CO2e
ES-4 Inventory of US Greenhouse Gas Emissions and Sinks 1990ndash2017
ES2 Recent Trends in US Greenhouse Gas Emissions and Sinks
In 2017 total gross US greenhouse gas emissions were 64567 MMT or million metric tons of carbon dioxide (CO2) Eq11 Total US emissions have increased by 13 percent from 1990 to 2017 and emissions decreased from 2016 to 2017 by 05 percent (355 MMT CO2 Eq) The decrease in total greenhouse gas emissions between 2016 and 2017 was driven in part by a decrease in CO2 emissions from fossil fuel combustion The decrease in CO2 emissions from fossil fuel combustion was a result of multiple factors including a continued shift from coal to natural gas and increased use of renewable energy in the electric power sector and milder weather that contributed to less overall electricity use
Relative to 1990 the baseline for this Inventory gross emissions in 2017 are higher by 13 percent down from a high of 157 percent above 1990 levels in 2007 Overall net emissions in 2017 were 130 percent below 2005 levels as shown in Table ES-2 Figure ES-1 through Figure ES-3 illustrate the overall trends in total US emissions by gas annual changes and absolute change since 1990 and Table ES-2 provides a detailed summary of gross US greenhouse gas emissions and sinks for 1990 through 2017 Note unless otherwise stated all tables and figures provide total gross emissions and exclude the greenhouse gas fluxes from the Land Use Land-Use Change and Forestry (LULUCF) sector (see Section ES3 Overview of Sector Emissions and Trends)
Figure ES-1 Gross US Greenhouse Gas Emissions by Gas (MMT CO2 Eq)
11 The gross emissions total presented in this report for the United States excludes emissions and removals from Land Use Land-Use Change and Forestry (LULUCF) The net emissions total presented in this report for the United States includes emissions and removals from LULUCF
httpswwwepagovsitesproductionfiles2019-04documentsus-ghg-inventory-2019-main-textpdf September 2019
This reflects fracking recession technical progress off-shoring ofmanufacturing Emissions are likely up since 2017
Emissions
Emissions per person
Itrsquos also interesting to look at the country by country breakdown interms of emissions per capita
IPCC 2007 Mitigation fig SPM3a
As of 2012 US had 454 tons C person and for India this numberwas 046 China was 18(httpcdiacornlgovtrendsemistop2011cap)
Emissions
The problem of stabilizing atmospheric CO2Emissions are about 13Gt C per year
The ocean and biosphere absorb about 45 of emissions (sofar)
This means the ocean and biosphere absorb 13 times 045 asymp 6GtC per year
As a rough guess this means that reducing emissions to 6GtC per year will stabilize atmospheric CO2 (but not climate)
This involves a 55 decrease For an average American thismeans this means reducing emissions from 45 tons per yearto about 20 if US share of total emissions stays constant Ifemissions are allocated equally to each of the worldrsquos 74bpeople then each of us gets 6Gt C 74b people or about 08ton This is an 82 decrease for the average American It isalso about the twice the level of the average Indian and halfthat of the average Chinese
Emissions
Summary
2013 emissions of CO2e were about 49Gt Of this 35Gt wasCO2 and of this about 30Gt from fossil fuels and 5Gt fromland use change and agriculture This is E in our model
Emission are growing rapidly about 2year between 2000and 2010 1970 CO2e was 30Gt
2010 CO2e 14 transport 18 buildings 21 industry 24AFOLU We could use this to calculate refinements of ρ5
The countries responsible for most of the stock are not thecountries responsible for most of the flow
Per capita emissions vary by a factor of about 10 between richand poor countries
There has been a decline in US emissions since 2008 due tofracking recession technical progress off shoring
Peak oil
Will we run out of fossil fuel INot soon enough to matter
0
200
400
600
800
Estimated Reserves
Emissions to Date
Gig
aton
s C
arbo
n
Oil Gas Coal Land Use
EIA
IPCCEIA
IPCC
100
200
300
Em
itted
CO
2 (p
pm)
0
200
400
600
800
We have oceans of coal and lots of oil and these figures predateUS fracking
Peak oil
Will we run out of fossil fuel II
Conclusion
Conclusion I
Here is where we stand with our model
maxIM
u(c1 c2) (14)
st W = c1 + I + M (15)
c2 = (1 + r)I minus γ(T2 minus T1)I (16)
E = (1 minus ρ4MW
)(ρ5(c1 + I)) (17)
P2 = ρ0E + P1 (18)
T2 = ρ1(P2 minus P1) + T1 (19)
We have enough pieces filled in to permit you to calculate theimpact on future climate of particular sorts of current consumptioneg burning a tank of propane on your bbq Wersquoll next start
Conclusion
Conclusion II
thinking about the effect of climate change on production γthough wersquoll make an aside to talk about measurement error first
Conclusion
Conclusion III
Each ppm of atmospheric CO2 corresponds to about 212 Gt C
and 778 Gt of CO2 Pay attention to the units people use
Not all gases are equal in their green house potential CO2 ismost common and most important but other gases are moreimportant per unit of emissions
Over the past 50 years about 55 of each emitted Gt of C
has stayed in the atmosphere The rest has been absorbed byland or oceans Thus it takes about 38 Gt C per 1ppm ofatmospheric CO2
Conclusion
Conclusion IV
Emissions are about 13Gt C for 2013 The rate at whichatmospheric CO2 is increasing has risen from about 1ppmyr1960s to 2ppm for 2000rsquos Since there is lots of fuel weshould expect atmospheric CO2 to continue to increase and atan increasing rate lsquobusiness as usual scenarios call foratmospheric CO2e gt 800 within 100 years
Not all countries are the same They are responsible fordifferent shares have different per capita emissions useemission more or less efficiently and are responsible fordifferent shares of historical emissions These factors are veryimportant obstacles to international agreements and alsosuggest the need for a richer model
Conclusion
Conclusion V
Steady state CO2 emissions are probably very small Sternsuggests less than 13 of current Our calculations suggest(1-055)=45
Carbon cycle
CO2 is not the only GHG I
From Stern 2008 table 81
Carbon cycle
CO2 is not the only GHG II
July 2019 concentration of CO2 was 412 ppm Using thenumbers above current CO2e is 412077 = 535CO2e
From the forcing tables we see that non-CO2 is has about halfthe forcing capacity of CO2 However non-CO2 is lesspersistent so it makes a smaller total contribution to warmingthan this share suggests
Carbon cycle
What is lsquoGlobal Warming Potentialrsquo I
We would like to calculate the rate at which we are willing totrade CH4 for CO2 To do this define αt as the change inradiative forcing from one unit of concentration of the gas at t
ieWm2
PPM Define GWP as warming potential relative to CO2
GWP(CH4 ) =
int T0 αCH4 (t)dtint T0 αCO2 (t)dt
Example suppose t = 1 2 3 and for CO2 (αCO2 (1) αCO2 (2) αCO2 (3)) = (1 1 1) and for CH4 (αCH4 (1) αCH4 (2) αCH4 (3)) = (2 0 0)Then GWP(CH4 ) = 2+0+0
1+1+1
Carbon cycle
What is lsquoGlobal Warming Potentialrsquo II
Issues
T is completely arbitrary GWP of CH4 for T = 20 100 500 isabout 63 21 9We care about damage not radiative forcing (see Schmalensee The
Energy Journal (1993)) To see this considerIf we anticipate that the world will end in 20 years then neitherCO2 nor CH4 is very harmful but CH4 causes a lot morewarming over that time than CO2If we plan to spend the next 20 years as we do now but then topermanently convert to an economy based on penguinfarming then CH4 emissions now are not very harmful but CO2is (because it is persistent)
We canrsquot really assign relative values to CO2 and CH4 until wesolve for the whole optimal path of emissions for both gasesso any definition of GWP is going to be unsatisfactory
Carbon cycle
Units
Stern 2007 p193 gives CO2e emissions for 2000 as 42Gt CO2e Hansen has 85 Gt C from fossil fuelCan we reconcile these numbers(Yes)
About 77 of CO2e is CO2
About 18 of CO2 is non fossil fuel (more on this later)
Stern reports CO2 Hansen C
so Sternrsquos 42 Gt CO2e becomes42 times (77(1 minus 18))times (1244) = 72 Gt of atmospheric C It would be closer but Stern uses 2000 numbers and Hansenrsquos 85is for about 2008
Atmospheric carbon cycle
Carbon cycle
Carbon is cycled back and forth between the atmosphere oceanand land by biological and chemical processes This means thatemissions donrsquot translate immediately into atmosphericconcentrations Stocksannual flows of C (not CO2 ) are
Atmosphere 800+45Gt
Ocean 40000+3Gt
Volcanos ndash-01Gt
Forests 600-16 Gt
Fossil fuels 5000-85
Sediments ndash-1Gt
Atmospheric carbon cycle
Fossil fuel emissions and deforestation put about 10Gt C in theatmosphere (ca 2007) Atmospheric C increased by about 45GtAbout 3Gt are absorbed by the ocean The remaining 25Gt arethought to be absorbed by plants (NB old numbers to go withfigure) Numbers from Hansen 2009 about the same as in Jacob 1999
Black = natural Red=Anthropogenic AOGCM models of carbon cycle are complicated IPCC 2007 Physical Science basis
figure 73
Atmospheric carbon cycle
Atmospheric CO2 cycle data I
Another way to see this is to look at the relationship betweenemissions and concentration directly
Calculate annual change in C ppm from Mauna Loa (eg)
Calculate annual emissions using emissions rates andconsumption data (more below)
Calculate ratio ∆CO2ppmFossil Fuel emissions = concentration yield of
emissions
Atmospheric carbon cycle
Atmospheric CO2 cycle data II
1950 1960 1970 1980 1990 2000 2010 0
2
4
6
8
10
Global Fossil Fuel CO2 EmissionsCO2 Airborne Fraction (7minusyear mean)
Em
issi
ons
(Gig
aton
s C
yea
r)
0
20
40
60
80
100
Air
born
e Fr
actio
n (
)
Hansen 2009 figure 16
Atmospheric carbon cycle
Atmospheric CO2 cycle data III
So concentration yield of emissions is about 55 Thus
(1055)= 18 Gt C emissions gives 1 Gt ton of atmospheric C
212 Gt atmospheric C to gives 1ppm atmospheric C (or CO2 )
Multiplying 18 times 212 = 38Gt C of emissions to get 1ppm ofatmospheric concentration
Recall the carbon cycle equation from our model
P2 = ρ0E + P1
We have just calculated that ρ0 = 138 = 026ppm C (or CO2 )
Gt C
What is ρ0 if we denominate emissions in terms of CO2
Atmospheric carbon cycle
Atmospheric CO2 cycle data IV
In Hansenrsquos graph the fraction of emissions retained in theatmosphere is CONSTANT as emissions are increasing This isthought to reflect increased absorbtion by plant lsquocarbonfertilizationrsquo or increased lsquonet primary productivityrsquo
In AOGCMrsquos the carbon cycle is modelled very carefully We reallywant to deal with the possibility that absorbtion varies withtemperature or CO2 (it probably does) and there is a lot ofuncertainty about this relationship
Consumption and emissions
Emissions for particular activities I
CO2 from gasoline 23 kgliter = 194 poundsgallon So1000 kg of CO2 emission results from 435 liters or 114gallons of gas (about 1 not burned is mostly N2O so CO2e ishigher)
CO2 from diesel 27 kgliter = 222 poundsgallon 1000 kg ofCO2 emission results from 370 liters or 97 gallons of dieselhttpwwwepagovotaqclimate420f05001htmcalculating
BBQ propane tank about 18 pounds propane = 24kg = 53 lbCO2 (NB Gasoline weighs 63 poundsgallon so 18 poundsof gas gives about 54 pounds CO2 Propane has morehydrogen per carbon atom than gasoline)
Consumption and emissions
Emissions for particular activities II
CO2 sequestration by 1 acre 90 year old pine forest inSoutheastern US is about 100 tons C about 1 tonacreyearSo burning this acre releases about 100 tons C or 367 tonsCO2 httpwwwepagovsequestrationfaqhtml For tropical forests about 18times as much not reliable source
CO2 from coal about 200 tons CO2 per ton (a lot of the stuffin coal is not burned ndash I think) or 2100lb CO2 per 1000 KWHfrom non-baseload coal burning electricity generation CO2eis higher Baseload will usually be lower (often nuclear orhydro) httpwwweiagovtoolsfaqsfaqcfmid=74ampt=11
Consumption and emissions
Emissions for particular activities III
For natural gas about 1200lb CO2 per 1000 KWH Sofracking is fantastic unless too much methane leaks beforeitrsquos burnt With 1 ton of methane worth 23 tons of CO2 about43 leakage makes coal and natural gas even (unless thereis methane leakage from coal mines) The rate of leakage iscurrently contested EPA current estimate is about 06 but05 is probably better (Allen et al PNAS 2013)
For reference Avg household in RI = 500KWHmo Avghousehold in TX = 1000KWHmohttpswwweiagovtoolsfaqsfaqcfmid=97ampt=3 (Feb 2016) Or averagehousehold in Providence sim 8000kwhyear in 2001 Dallas sim18500kwhyear (Glaeser and Kahn JUE 2010)
Consumption and emissions
Emissions for particular activities IV
For thinking about fracking also consider the following
Consumption and emissions
Global emissions per unit of consumption ca 2013
Using these sorts of particular numbers together with informationabout aggregate consumption one can calculate world emissions
Global annual emissions ca 2013 are about 49Gt CO2e or49 times 12
44 sim 133 Gt C (more on this later)
World GDP in 2013 is about 77 trillion USD (NB this is W inour model)
Dividingwe have 133times109 tons C77times1012000USD = 133
7700ton CUSD sim 017 kg C
USD (1 ton= 1000 kg) Multiply by 4412 for CO2 instead of C
Recall the third equation from our global warming model
E = (1 minus ρ4MW
)(ρ5(c1 + I)) (7)
Wersquove just calculated ρ5 Why is this sloppy
Consumption and emissions
Emissions per unit of consumption by countryItrsquos also interesting to look at the country by countrybreakdown(ca 2004) The US and Canada make a lot of stuffper ton of emissions
IPCC 2007 Mitigation fig SPM3b
What if China and Africa made same output at USCAemission rates This is why technology transfer is importantCompare 068 kg CO2e per dollar ca 2004 to my calculationof 017 kg C per dollar 2013 How important is technicalprogress
Consumption and emissions
Technological progress I
httpwww3epagovclimatechangescienceindicatorsghgus-ghg-emissionshtml January 2016
Consumption and emissions
Technological progress II
Nordhaus does this calculation every year country by country
Russia
India
World
EU
US
China
Consumption and emissions
Emissions - Summary
Wersquove now calculated ρ5 emissions per GDP at about 017kgC per dollar ca 2013Looking at the data a little more carefully highlights twodeficiencies on our model
Technological progress is at work so this ratio changes overtimeThere are huge difference across places in this ratio
This highlights the importance of technological progress andtechnology transfer in solving the problem of climate change
Wersquoll address this when we get to the Nordhaus model
Emissions
Emissions trends and levels
Recall
maxIM
u(c1 c2) (8)
st W = c1 + I + M (9)
c2 = (1 + r)I minus γ(T2 minus T1)I (10)
E = (1 minus ρ4MW
)(ρ5(c1 + I)) (11)
P2 = ρ0E + P1 (12)
T2 = ρ1(P2 minus P1) + T1 (13)
Wersquove filled in a bit more The next step is to look at E This meanslooking at trends and levels in CO2 emissions
Emissions
CO2e 1970-2010
IPCC 2013 WG3 fig TS1
Right panel gives confidence bounds for 2010 49Gt CO2e in 2010
Emissions
CO2 by purpose and country income 1750-2010
IPCC 2013 WG3 fig TS2
Emissions
Hansenrsquos version of the same thing
Flow StockHansen 2009 fig 27
Contributions to stock and flow are very different At thenegotiating table developing countries want the right to emit sinceeveryone else had their turn
Emissions
2010 CO2e by purpose
IPCC 2013 WG3 fig TS3
Emissions
2010 CO2e by purpose and country income
IPCC 2013 WG3 fig TS3
Emissions
US 1990-2017 CO2e
ES-4 Inventory of US Greenhouse Gas Emissions and Sinks 1990ndash2017
ES2 Recent Trends in US Greenhouse Gas Emissions and Sinks
In 2017 total gross US greenhouse gas emissions were 64567 MMT or million metric tons of carbon dioxide (CO2) Eq11 Total US emissions have increased by 13 percent from 1990 to 2017 and emissions decreased from 2016 to 2017 by 05 percent (355 MMT CO2 Eq) The decrease in total greenhouse gas emissions between 2016 and 2017 was driven in part by a decrease in CO2 emissions from fossil fuel combustion The decrease in CO2 emissions from fossil fuel combustion was a result of multiple factors including a continued shift from coal to natural gas and increased use of renewable energy in the electric power sector and milder weather that contributed to less overall electricity use
Relative to 1990 the baseline for this Inventory gross emissions in 2017 are higher by 13 percent down from a high of 157 percent above 1990 levels in 2007 Overall net emissions in 2017 were 130 percent below 2005 levels as shown in Table ES-2 Figure ES-1 through Figure ES-3 illustrate the overall trends in total US emissions by gas annual changes and absolute change since 1990 and Table ES-2 provides a detailed summary of gross US greenhouse gas emissions and sinks for 1990 through 2017 Note unless otherwise stated all tables and figures provide total gross emissions and exclude the greenhouse gas fluxes from the Land Use Land-Use Change and Forestry (LULUCF) sector (see Section ES3 Overview of Sector Emissions and Trends)
Figure ES-1 Gross US Greenhouse Gas Emissions by Gas (MMT CO2 Eq)
11 The gross emissions total presented in this report for the United States excludes emissions and removals from Land Use Land-Use Change and Forestry (LULUCF) The net emissions total presented in this report for the United States includes emissions and removals from LULUCF
httpswwwepagovsitesproductionfiles2019-04documentsus-ghg-inventory-2019-main-textpdf September 2019
This reflects fracking recession technical progress off-shoring ofmanufacturing Emissions are likely up since 2017
Emissions
Emissions per person
Itrsquos also interesting to look at the country by country breakdown interms of emissions per capita
IPCC 2007 Mitigation fig SPM3a
As of 2012 US had 454 tons C person and for India this numberwas 046 China was 18(httpcdiacornlgovtrendsemistop2011cap)
Emissions
The problem of stabilizing atmospheric CO2Emissions are about 13Gt C per year
The ocean and biosphere absorb about 45 of emissions (sofar)
This means the ocean and biosphere absorb 13 times 045 asymp 6GtC per year
As a rough guess this means that reducing emissions to 6GtC per year will stabilize atmospheric CO2 (but not climate)
This involves a 55 decrease For an average American thismeans this means reducing emissions from 45 tons per yearto about 20 if US share of total emissions stays constant Ifemissions are allocated equally to each of the worldrsquos 74bpeople then each of us gets 6Gt C 74b people or about 08ton This is an 82 decrease for the average American It isalso about the twice the level of the average Indian and halfthat of the average Chinese
Emissions
Summary
2013 emissions of CO2e were about 49Gt Of this 35Gt wasCO2 and of this about 30Gt from fossil fuels and 5Gt fromland use change and agriculture This is E in our model
Emission are growing rapidly about 2year between 2000and 2010 1970 CO2e was 30Gt
2010 CO2e 14 transport 18 buildings 21 industry 24AFOLU We could use this to calculate refinements of ρ5
The countries responsible for most of the stock are not thecountries responsible for most of the flow
Per capita emissions vary by a factor of about 10 between richand poor countries
There has been a decline in US emissions since 2008 due tofracking recession technical progress off shoring
Peak oil
Will we run out of fossil fuel INot soon enough to matter
0
200
400
600
800
Estimated Reserves
Emissions to Date
Gig
aton
s C
arbo
n
Oil Gas Coal Land Use
EIA
IPCCEIA
IPCC
100
200
300
Em
itted
CO
2 (p
pm)
0
200
400
600
800
We have oceans of coal and lots of oil and these figures predateUS fracking
Peak oil
Will we run out of fossil fuel II
Conclusion
Conclusion I
Here is where we stand with our model
maxIM
u(c1 c2) (14)
st W = c1 + I + M (15)
c2 = (1 + r)I minus γ(T2 minus T1)I (16)
E = (1 minus ρ4MW
)(ρ5(c1 + I)) (17)
P2 = ρ0E + P1 (18)
T2 = ρ1(P2 minus P1) + T1 (19)
We have enough pieces filled in to permit you to calculate theimpact on future climate of particular sorts of current consumptioneg burning a tank of propane on your bbq Wersquoll next start
Conclusion
Conclusion II
thinking about the effect of climate change on production γthough wersquoll make an aside to talk about measurement error first
Conclusion
Conclusion III
Each ppm of atmospheric CO2 corresponds to about 212 Gt C
and 778 Gt of CO2 Pay attention to the units people use
Not all gases are equal in their green house potential CO2 ismost common and most important but other gases are moreimportant per unit of emissions
Over the past 50 years about 55 of each emitted Gt of C
has stayed in the atmosphere The rest has been absorbed byland or oceans Thus it takes about 38 Gt C per 1ppm ofatmospheric CO2
Conclusion
Conclusion IV
Emissions are about 13Gt C for 2013 The rate at whichatmospheric CO2 is increasing has risen from about 1ppmyr1960s to 2ppm for 2000rsquos Since there is lots of fuel weshould expect atmospheric CO2 to continue to increase and atan increasing rate lsquobusiness as usual scenarios call foratmospheric CO2e gt 800 within 100 years
Not all countries are the same They are responsible fordifferent shares have different per capita emissions useemission more or less efficiently and are responsible fordifferent shares of historical emissions These factors are veryimportant obstacles to international agreements and alsosuggest the need for a richer model
Conclusion
Conclusion V
Steady state CO2 emissions are probably very small Sternsuggests less than 13 of current Our calculations suggest(1-055)=45
Carbon cycle
CO2 is not the only GHG II
July 2019 concentration of CO2 was 412 ppm Using thenumbers above current CO2e is 412077 = 535CO2e
From the forcing tables we see that non-CO2 is has about halfthe forcing capacity of CO2 However non-CO2 is lesspersistent so it makes a smaller total contribution to warmingthan this share suggests
Carbon cycle
What is lsquoGlobal Warming Potentialrsquo I
We would like to calculate the rate at which we are willing totrade CH4 for CO2 To do this define αt as the change inradiative forcing from one unit of concentration of the gas at t
ieWm2
PPM Define GWP as warming potential relative to CO2
GWP(CH4 ) =
int T0 αCH4 (t)dtint T0 αCO2 (t)dt
Example suppose t = 1 2 3 and for CO2 (αCO2 (1) αCO2 (2) αCO2 (3)) = (1 1 1) and for CH4 (αCH4 (1) αCH4 (2) αCH4 (3)) = (2 0 0)Then GWP(CH4 ) = 2+0+0
1+1+1
Carbon cycle
What is lsquoGlobal Warming Potentialrsquo II
Issues
T is completely arbitrary GWP of CH4 for T = 20 100 500 isabout 63 21 9We care about damage not radiative forcing (see Schmalensee The
Energy Journal (1993)) To see this considerIf we anticipate that the world will end in 20 years then neitherCO2 nor CH4 is very harmful but CH4 causes a lot morewarming over that time than CO2If we plan to spend the next 20 years as we do now but then topermanently convert to an economy based on penguinfarming then CH4 emissions now are not very harmful but CO2is (because it is persistent)
We canrsquot really assign relative values to CO2 and CH4 until wesolve for the whole optimal path of emissions for both gasesso any definition of GWP is going to be unsatisfactory
Carbon cycle
Units
Stern 2007 p193 gives CO2e emissions for 2000 as 42Gt CO2e Hansen has 85 Gt C from fossil fuelCan we reconcile these numbers(Yes)
About 77 of CO2e is CO2
About 18 of CO2 is non fossil fuel (more on this later)
Stern reports CO2 Hansen C
so Sternrsquos 42 Gt CO2e becomes42 times (77(1 minus 18))times (1244) = 72 Gt of atmospheric C It would be closer but Stern uses 2000 numbers and Hansenrsquos 85is for about 2008
Atmospheric carbon cycle
Carbon cycle
Carbon is cycled back and forth between the atmosphere oceanand land by biological and chemical processes This means thatemissions donrsquot translate immediately into atmosphericconcentrations Stocksannual flows of C (not CO2 ) are
Atmosphere 800+45Gt
Ocean 40000+3Gt
Volcanos ndash-01Gt
Forests 600-16 Gt
Fossil fuels 5000-85
Sediments ndash-1Gt
Atmospheric carbon cycle
Fossil fuel emissions and deforestation put about 10Gt C in theatmosphere (ca 2007) Atmospheric C increased by about 45GtAbout 3Gt are absorbed by the ocean The remaining 25Gt arethought to be absorbed by plants (NB old numbers to go withfigure) Numbers from Hansen 2009 about the same as in Jacob 1999
Black = natural Red=Anthropogenic AOGCM models of carbon cycle are complicated IPCC 2007 Physical Science basis
figure 73
Atmospheric carbon cycle
Atmospheric CO2 cycle data I
Another way to see this is to look at the relationship betweenemissions and concentration directly
Calculate annual change in C ppm from Mauna Loa (eg)
Calculate annual emissions using emissions rates andconsumption data (more below)
Calculate ratio ∆CO2ppmFossil Fuel emissions = concentration yield of
emissions
Atmospheric carbon cycle
Atmospheric CO2 cycle data II
1950 1960 1970 1980 1990 2000 2010 0
2
4
6
8
10
Global Fossil Fuel CO2 EmissionsCO2 Airborne Fraction (7minusyear mean)
Em
issi
ons
(Gig
aton
s C
yea
r)
0
20
40
60
80
100
Air
born
e Fr
actio
n (
)
Hansen 2009 figure 16
Atmospheric carbon cycle
Atmospheric CO2 cycle data III
So concentration yield of emissions is about 55 Thus
(1055)= 18 Gt C emissions gives 1 Gt ton of atmospheric C
212 Gt atmospheric C to gives 1ppm atmospheric C (or CO2 )
Multiplying 18 times 212 = 38Gt C of emissions to get 1ppm ofatmospheric concentration
Recall the carbon cycle equation from our model
P2 = ρ0E + P1
We have just calculated that ρ0 = 138 = 026ppm C (or CO2 )
Gt C
What is ρ0 if we denominate emissions in terms of CO2
Atmospheric carbon cycle
Atmospheric CO2 cycle data IV
In Hansenrsquos graph the fraction of emissions retained in theatmosphere is CONSTANT as emissions are increasing This isthought to reflect increased absorbtion by plant lsquocarbonfertilizationrsquo or increased lsquonet primary productivityrsquo
In AOGCMrsquos the carbon cycle is modelled very carefully We reallywant to deal with the possibility that absorbtion varies withtemperature or CO2 (it probably does) and there is a lot ofuncertainty about this relationship
Consumption and emissions
Emissions for particular activities I
CO2 from gasoline 23 kgliter = 194 poundsgallon So1000 kg of CO2 emission results from 435 liters or 114gallons of gas (about 1 not burned is mostly N2O so CO2e ishigher)
CO2 from diesel 27 kgliter = 222 poundsgallon 1000 kg ofCO2 emission results from 370 liters or 97 gallons of dieselhttpwwwepagovotaqclimate420f05001htmcalculating
BBQ propane tank about 18 pounds propane = 24kg = 53 lbCO2 (NB Gasoline weighs 63 poundsgallon so 18 poundsof gas gives about 54 pounds CO2 Propane has morehydrogen per carbon atom than gasoline)
Consumption and emissions
Emissions for particular activities II
CO2 sequestration by 1 acre 90 year old pine forest inSoutheastern US is about 100 tons C about 1 tonacreyearSo burning this acre releases about 100 tons C or 367 tonsCO2 httpwwwepagovsequestrationfaqhtml For tropical forests about 18times as much not reliable source
CO2 from coal about 200 tons CO2 per ton (a lot of the stuffin coal is not burned ndash I think) or 2100lb CO2 per 1000 KWHfrom non-baseload coal burning electricity generation CO2eis higher Baseload will usually be lower (often nuclear orhydro) httpwwweiagovtoolsfaqsfaqcfmid=74ampt=11
Consumption and emissions
Emissions for particular activities III
For natural gas about 1200lb CO2 per 1000 KWH Sofracking is fantastic unless too much methane leaks beforeitrsquos burnt With 1 ton of methane worth 23 tons of CO2 about43 leakage makes coal and natural gas even (unless thereis methane leakage from coal mines) The rate of leakage iscurrently contested EPA current estimate is about 06 but05 is probably better (Allen et al PNAS 2013)
For reference Avg household in RI = 500KWHmo Avghousehold in TX = 1000KWHmohttpswwweiagovtoolsfaqsfaqcfmid=97ampt=3 (Feb 2016) Or averagehousehold in Providence sim 8000kwhyear in 2001 Dallas sim18500kwhyear (Glaeser and Kahn JUE 2010)
Consumption and emissions
Emissions for particular activities IV
For thinking about fracking also consider the following
Consumption and emissions
Global emissions per unit of consumption ca 2013
Using these sorts of particular numbers together with informationabout aggregate consumption one can calculate world emissions
Global annual emissions ca 2013 are about 49Gt CO2e or49 times 12
44 sim 133 Gt C (more on this later)
World GDP in 2013 is about 77 trillion USD (NB this is W inour model)
Dividingwe have 133times109 tons C77times1012000USD = 133
7700ton CUSD sim 017 kg C
USD (1 ton= 1000 kg) Multiply by 4412 for CO2 instead of C
Recall the third equation from our global warming model
E = (1 minus ρ4MW
)(ρ5(c1 + I)) (7)
Wersquove just calculated ρ5 Why is this sloppy
Consumption and emissions
Emissions per unit of consumption by countryItrsquos also interesting to look at the country by countrybreakdown(ca 2004) The US and Canada make a lot of stuffper ton of emissions
IPCC 2007 Mitigation fig SPM3b
What if China and Africa made same output at USCAemission rates This is why technology transfer is importantCompare 068 kg CO2e per dollar ca 2004 to my calculationof 017 kg C per dollar 2013 How important is technicalprogress
Consumption and emissions
Technological progress I
httpwww3epagovclimatechangescienceindicatorsghgus-ghg-emissionshtml January 2016
Consumption and emissions
Technological progress II
Nordhaus does this calculation every year country by country
Russia
India
World
EU
US
China
Consumption and emissions
Emissions - Summary
Wersquove now calculated ρ5 emissions per GDP at about 017kgC per dollar ca 2013Looking at the data a little more carefully highlights twodeficiencies on our model
Technological progress is at work so this ratio changes overtimeThere are huge difference across places in this ratio
This highlights the importance of technological progress andtechnology transfer in solving the problem of climate change
Wersquoll address this when we get to the Nordhaus model
Emissions
Emissions trends and levels
Recall
maxIM
u(c1 c2) (8)
st W = c1 + I + M (9)
c2 = (1 + r)I minus γ(T2 minus T1)I (10)
E = (1 minus ρ4MW
)(ρ5(c1 + I)) (11)
P2 = ρ0E + P1 (12)
T2 = ρ1(P2 minus P1) + T1 (13)
Wersquove filled in a bit more The next step is to look at E This meanslooking at trends and levels in CO2 emissions
Emissions
CO2e 1970-2010
IPCC 2013 WG3 fig TS1
Right panel gives confidence bounds for 2010 49Gt CO2e in 2010
Emissions
CO2 by purpose and country income 1750-2010
IPCC 2013 WG3 fig TS2
Emissions
Hansenrsquos version of the same thing
Flow StockHansen 2009 fig 27
Contributions to stock and flow are very different At thenegotiating table developing countries want the right to emit sinceeveryone else had their turn
Emissions
2010 CO2e by purpose
IPCC 2013 WG3 fig TS3
Emissions
2010 CO2e by purpose and country income
IPCC 2013 WG3 fig TS3
Emissions
US 1990-2017 CO2e
ES-4 Inventory of US Greenhouse Gas Emissions and Sinks 1990ndash2017
ES2 Recent Trends in US Greenhouse Gas Emissions and Sinks
In 2017 total gross US greenhouse gas emissions were 64567 MMT or million metric tons of carbon dioxide (CO2) Eq11 Total US emissions have increased by 13 percent from 1990 to 2017 and emissions decreased from 2016 to 2017 by 05 percent (355 MMT CO2 Eq) The decrease in total greenhouse gas emissions between 2016 and 2017 was driven in part by a decrease in CO2 emissions from fossil fuel combustion The decrease in CO2 emissions from fossil fuel combustion was a result of multiple factors including a continued shift from coal to natural gas and increased use of renewable energy in the electric power sector and milder weather that contributed to less overall electricity use
Relative to 1990 the baseline for this Inventory gross emissions in 2017 are higher by 13 percent down from a high of 157 percent above 1990 levels in 2007 Overall net emissions in 2017 were 130 percent below 2005 levels as shown in Table ES-2 Figure ES-1 through Figure ES-3 illustrate the overall trends in total US emissions by gas annual changes and absolute change since 1990 and Table ES-2 provides a detailed summary of gross US greenhouse gas emissions and sinks for 1990 through 2017 Note unless otherwise stated all tables and figures provide total gross emissions and exclude the greenhouse gas fluxes from the Land Use Land-Use Change and Forestry (LULUCF) sector (see Section ES3 Overview of Sector Emissions and Trends)
Figure ES-1 Gross US Greenhouse Gas Emissions by Gas (MMT CO2 Eq)
11 The gross emissions total presented in this report for the United States excludes emissions and removals from Land Use Land-Use Change and Forestry (LULUCF) The net emissions total presented in this report for the United States includes emissions and removals from LULUCF
httpswwwepagovsitesproductionfiles2019-04documentsus-ghg-inventory-2019-main-textpdf September 2019
This reflects fracking recession technical progress off-shoring ofmanufacturing Emissions are likely up since 2017
Emissions
Emissions per person
Itrsquos also interesting to look at the country by country breakdown interms of emissions per capita
IPCC 2007 Mitigation fig SPM3a
As of 2012 US had 454 tons C person and for India this numberwas 046 China was 18(httpcdiacornlgovtrendsemistop2011cap)
Emissions
The problem of stabilizing atmospheric CO2Emissions are about 13Gt C per year
The ocean and biosphere absorb about 45 of emissions (sofar)
This means the ocean and biosphere absorb 13 times 045 asymp 6GtC per year
As a rough guess this means that reducing emissions to 6GtC per year will stabilize atmospheric CO2 (but not climate)
This involves a 55 decrease For an average American thismeans this means reducing emissions from 45 tons per yearto about 20 if US share of total emissions stays constant Ifemissions are allocated equally to each of the worldrsquos 74bpeople then each of us gets 6Gt C 74b people or about 08ton This is an 82 decrease for the average American It isalso about the twice the level of the average Indian and halfthat of the average Chinese
Emissions
Summary
2013 emissions of CO2e were about 49Gt Of this 35Gt wasCO2 and of this about 30Gt from fossil fuels and 5Gt fromland use change and agriculture This is E in our model
Emission are growing rapidly about 2year between 2000and 2010 1970 CO2e was 30Gt
2010 CO2e 14 transport 18 buildings 21 industry 24AFOLU We could use this to calculate refinements of ρ5
The countries responsible for most of the stock are not thecountries responsible for most of the flow
Per capita emissions vary by a factor of about 10 between richand poor countries
There has been a decline in US emissions since 2008 due tofracking recession technical progress off shoring
Peak oil
Will we run out of fossil fuel INot soon enough to matter
0
200
400
600
800
Estimated Reserves
Emissions to Date
Gig
aton
s C
arbo
n
Oil Gas Coal Land Use
EIA
IPCCEIA
IPCC
100
200
300
Em
itted
CO
2 (p
pm)
0
200
400
600
800
We have oceans of coal and lots of oil and these figures predateUS fracking
Peak oil
Will we run out of fossil fuel II
Conclusion
Conclusion I
Here is where we stand with our model
maxIM
u(c1 c2) (14)
st W = c1 + I + M (15)
c2 = (1 + r)I minus γ(T2 minus T1)I (16)
E = (1 minus ρ4MW
)(ρ5(c1 + I)) (17)
P2 = ρ0E + P1 (18)
T2 = ρ1(P2 minus P1) + T1 (19)
We have enough pieces filled in to permit you to calculate theimpact on future climate of particular sorts of current consumptioneg burning a tank of propane on your bbq Wersquoll next start
Conclusion
Conclusion II
thinking about the effect of climate change on production γthough wersquoll make an aside to talk about measurement error first
Conclusion
Conclusion III
Each ppm of atmospheric CO2 corresponds to about 212 Gt C
and 778 Gt of CO2 Pay attention to the units people use
Not all gases are equal in their green house potential CO2 ismost common and most important but other gases are moreimportant per unit of emissions
Over the past 50 years about 55 of each emitted Gt of C
has stayed in the atmosphere The rest has been absorbed byland or oceans Thus it takes about 38 Gt C per 1ppm ofatmospheric CO2
Conclusion
Conclusion IV
Emissions are about 13Gt C for 2013 The rate at whichatmospheric CO2 is increasing has risen from about 1ppmyr1960s to 2ppm for 2000rsquos Since there is lots of fuel weshould expect atmospheric CO2 to continue to increase and atan increasing rate lsquobusiness as usual scenarios call foratmospheric CO2e gt 800 within 100 years
Not all countries are the same They are responsible fordifferent shares have different per capita emissions useemission more or less efficiently and are responsible fordifferent shares of historical emissions These factors are veryimportant obstacles to international agreements and alsosuggest the need for a richer model
Conclusion
Conclusion V
Steady state CO2 emissions are probably very small Sternsuggests less than 13 of current Our calculations suggest(1-055)=45
Carbon cycle
What is lsquoGlobal Warming Potentialrsquo I
We would like to calculate the rate at which we are willing totrade CH4 for CO2 To do this define αt as the change inradiative forcing from one unit of concentration of the gas at t
ieWm2
PPM Define GWP as warming potential relative to CO2
GWP(CH4 ) =
int T0 αCH4 (t)dtint T0 αCO2 (t)dt
Example suppose t = 1 2 3 and for CO2 (αCO2 (1) αCO2 (2) αCO2 (3)) = (1 1 1) and for CH4 (αCH4 (1) αCH4 (2) αCH4 (3)) = (2 0 0)Then GWP(CH4 ) = 2+0+0
1+1+1
Carbon cycle
What is lsquoGlobal Warming Potentialrsquo II
Issues
T is completely arbitrary GWP of CH4 for T = 20 100 500 isabout 63 21 9We care about damage not radiative forcing (see Schmalensee The
Energy Journal (1993)) To see this considerIf we anticipate that the world will end in 20 years then neitherCO2 nor CH4 is very harmful but CH4 causes a lot morewarming over that time than CO2If we plan to spend the next 20 years as we do now but then topermanently convert to an economy based on penguinfarming then CH4 emissions now are not very harmful but CO2is (because it is persistent)
We canrsquot really assign relative values to CO2 and CH4 until wesolve for the whole optimal path of emissions for both gasesso any definition of GWP is going to be unsatisfactory
Carbon cycle
Units
Stern 2007 p193 gives CO2e emissions for 2000 as 42Gt CO2e Hansen has 85 Gt C from fossil fuelCan we reconcile these numbers(Yes)
About 77 of CO2e is CO2
About 18 of CO2 is non fossil fuel (more on this later)
Stern reports CO2 Hansen C
so Sternrsquos 42 Gt CO2e becomes42 times (77(1 minus 18))times (1244) = 72 Gt of atmospheric C It would be closer but Stern uses 2000 numbers and Hansenrsquos 85is for about 2008
Atmospheric carbon cycle
Carbon cycle
Carbon is cycled back and forth between the atmosphere oceanand land by biological and chemical processes This means thatemissions donrsquot translate immediately into atmosphericconcentrations Stocksannual flows of C (not CO2 ) are
Atmosphere 800+45Gt
Ocean 40000+3Gt
Volcanos ndash-01Gt
Forests 600-16 Gt
Fossil fuels 5000-85
Sediments ndash-1Gt
Atmospheric carbon cycle
Fossil fuel emissions and deforestation put about 10Gt C in theatmosphere (ca 2007) Atmospheric C increased by about 45GtAbout 3Gt are absorbed by the ocean The remaining 25Gt arethought to be absorbed by plants (NB old numbers to go withfigure) Numbers from Hansen 2009 about the same as in Jacob 1999
Black = natural Red=Anthropogenic AOGCM models of carbon cycle are complicated IPCC 2007 Physical Science basis
figure 73
Atmospheric carbon cycle
Atmospheric CO2 cycle data I
Another way to see this is to look at the relationship betweenemissions and concentration directly
Calculate annual change in C ppm from Mauna Loa (eg)
Calculate annual emissions using emissions rates andconsumption data (more below)
Calculate ratio ∆CO2ppmFossil Fuel emissions = concentration yield of
emissions
Atmospheric carbon cycle
Atmospheric CO2 cycle data II
1950 1960 1970 1980 1990 2000 2010 0
2
4
6
8
10
Global Fossil Fuel CO2 EmissionsCO2 Airborne Fraction (7minusyear mean)
Em
issi
ons
(Gig
aton
s C
yea
r)
0
20
40
60
80
100
Air
born
e Fr
actio
n (
)
Hansen 2009 figure 16
Atmospheric carbon cycle
Atmospheric CO2 cycle data III
So concentration yield of emissions is about 55 Thus
(1055)= 18 Gt C emissions gives 1 Gt ton of atmospheric C
212 Gt atmospheric C to gives 1ppm atmospheric C (or CO2 )
Multiplying 18 times 212 = 38Gt C of emissions to get 1ppm ofatmospheric concentration
Recall the carbon cycle equation from our model
P2 = ρ0E + P1
We have just calculated that ρ0 = 138 = 026ppm C (or CO2 )
Gt C
What is ρ0 if we denominate emissions in terms of CO2
Atmospheric carbon cycle
Atmospheric CO2 cycle data IV
In Hansenrsquos graph the fraction of emissions retained in theatmosphere is CONSTANT as emissions are increasing This isthought to reflect increased absorbtion by plant lsquocarbonfertilizationrsquo or increased lsquonet primary productivityrsquo
In AOGCMrsquos the carbon cycle is modelled very carefully We reallywant to deal with the possibility that absorbtion varies withtemperature or CO2 (it probably does) and there is a lot ofuncertainty about this relationship
Consumption and emissions
Emissions for particular activities I
CO2 from gasoline 23 kgliter = 194 poundsgallon So1000 kg of CO2 emission results from 435 liters or 114gallons of gas (about 1 not burned is mostly N2O so CO2e ishigher)
CO2 from diesel 27 kgliter = 222 poundsgallon 1000 kg ofCO2 emission results from 370 liters or 97 gallons of dieselhttpwwwepagovotaqclimate420f05001htmcalculating
BBQ propane tank about 18 pounds propane = 24kg = 53 lbCO2 (NB Gasoline weighs 63 poundsgallon so 18 poundsof gas gives about 54 pounds CO2 Propane has morehydrogen per carbon atom than gasoline)
Consumption and emissions
Emissions for particular activities II
CO2 sequestration by 1 acre 90 year old pine forest inSoutheastern US is about 100 tons C about 1 tonacreyearSo burning this acre releases about 100 tons C or 367 tonsCO2 httpwwwepagovsequestrationfaqhtml For tropical forests about 18times as much not reliable source
CO2 from coal about 200 tons CO2 per ton (a lot of the stuffin coal is not burned ndash I think) or 2100lb CO2 per 1000 KWHfrom non-baseload coal burning electricity generation CO2eis higher Baseload will usually be lower (often nuclear orhydro) httpwwweiagovtoolsfaqsfaqcfmid=74ampt=11
Consumption and emissions
Emissions for particular activities III
For natural gas about 1200lb CO2 per 1000 KWH Sofracking is fantastic unless too much methane leaks beforeitrsquos burnt With 1 ton of methane worth 23 tons of CO2 about43 leakage makes coal and natural gas even (unless thereis methane leakage from coal mines) The rate of leakage iscurrently contested EPA current estimate is about 06 but05 is probably better (Allen et al PNAS 2013)
For reference Avg household in RI = 500KWHmo Avghousehold in TX = 1000KWHmohttpswwweiagovtoolsfaqsfaqcfmid=97ampt=3 (Feb 2016) Or averagehousehold in Providence sim 8000kwhyear in 2001 Dallas sim18500kwhyear (Glaeser and Kahn JUE 2010)
Consumption and emissions
Emissions for particular activities IV
For thinking about fracking also consider the following
Consumption and emissions
Global emissions per unit of consumption ca 2013
Using these sorts of particular numbers together with informationabout aggregate consumption one can calculate world emissions
Global annual emissions ca 2013 are about 49Gt CO2e or49 times 12
44 sim 133 Gt C (more on this later)
World GDP in 2013 is about 77 trillion USD (NB this is W inour model)
Dividingwe have 133times109 tons C77times1012000USD = 133
7700ton CUSD sim 017 kg C
USD (1 ton= 1000 kg) Multiply by 4412 for CO2 instead of C
Recall the third equation from our global warming model
E = (1 minus ρ4MW
)(ρ5(c1 + I)) (7)
Wersquove just calculated ρ5 Why is this sloppy
Consumption and emissions
Emissions per unit of consumption by countryItrsquos also interesting to look at the country by countrybreakdown(ca 2004) The US and Canada make a lot of stuffper ton of emissions
IPCC 2007 Mitigation fig SPM3b
What if China and Africa made same output at USCAemission rates This is why technology transfer is importantCompare 068 kg CO2e per dollar ca 2004 to my calculationof 017 kg C per dollar 2013 How important is technicalprogress
Consumption and emissions
Technological progress I
httpwww3epagovclimatechangescienceindicatorsghgus-ghg-emissionshtml January 2016
Consumption and emissions
Technological progress II
Nordhaus does this calculation every year country by country
Russia
India
World
EU
US
China
Consumption and emissions
Emissions - Summary
Wersquove now calculated ρ5 emissions per GDP at about 017kgC per dollar ca 2013Looking at the data a little more carefully highlights twodeficiencies on our model
Technological progress is at work so this ratio changes overtimeThere are huge difference across places in this ratio
This highlights the importance of technological progress andtechnology transfer in solving the problem of climate change
Wersquoll address this when we get to the Nordhaus model
Emissions
Emissions trends and levels
Recall
maxIM
u(c1 c2) (8)
st W = c1 + I + M (9)
c2 = (1 + r)I minus γ(T2 minus T1)I (10)
E = (1 minus ρ4MW
)(ρ5(c1 + I)) (11)
P2 = ρ0E + P1 (12)
T2 = ρ1(P2 minus P1) + T1 (13)
Wersquove filled in a bit more The next step is to look at E This meanslooking at trends and levels in CO2 emissions
Emissions
CO2e 1970-2010
IPCC 2013 WG3 fig TS1
Right panel gives confidence bounds for 2010 49Gt CO2e in 2010
Emissions
CO2 by purpose and country income 1750-2010
IPCC 2013 WG3 fig TS2
Emissions
Hansenrsquos version of the same thing
Flow StockHansen 2009 fig 27
Contributions to stock and flow are very different At thenegotiating table developing countries want the right to emit sinceeveryone else had their turn
Emissions
2010 CO2e by purpose
IPCC 2013 WG3 fig TS3
Emissions
2010 CO2e by purpose and country income
IPCC 2013 WG3 fig TS3
Emissions
US 1990-2017 CO2e
ES-4 Inventory of US Greenhouse Gas Emissions and Sinks 1990ndash2017
ES2 Recent Trends in US Greenhouse Gas Emissions and Sinks
In 2017 total gross US greenhouse gas emissions were 64567 MMT or million metric tons of carbon dioxide (CO2) Eq11 Total US emissions have increased by 13 percent from 1990 to 2017 and emissions decreased from 2016 to 2017 by 05 percent (355 MMT CO2 Eq) The decrease in total greenhouse gas emissions between 2016 and 2017 was driven in part by a decrease in CO2 emissions from fossil fuel combustion The decrease in CO2 emissions from fossil fuel combustion was a result of multiple factors including a continued shift from coal to natural gas and increased use of renewable energy in the electric power sector and milder weather that contributed to less overall electricity use
Relative to 1990 the baseline for this Inventory gross emissions in 2017 are higher by 13 percent down from a high of 157 percent above 1990 levels in 2007 Overall net emissions in 2017 were 130 percent below 2005 levels as shown in Table ES-2 Figure ES-1 through Figure ES-3 illustrate the overall trends in total US emissions by gas annual changes and absolute change since 1990 and Table ES-2 provides a detailed summary of gross US greenhouse gas emissions and sinks for 1990 through 2017 Note unless otherwise stated all tables and figures provide total gross emissions and exclude the greenhouse gas fluxes from the Land Use Land-Use Change and Forestry (LULUCF) sector (see Section ES3 Overview of Sector Emissions and Trends)
Figure ES-1 Gross US Greenhouse Gas Emissions by Gas (MMT CO2 Eq)
11 The gross emissions total presented in this report for the United States excludes emissions and removals from Land Use Land-Use Change and Forestry (LULUCF) The net emissions total presented in this report for the United States includes emissions and removals from LULUCF
httpswwwepagovsitesproductionfiles2019-04documentsus-ghg-inventory-2019-main-textpdf September 2019
This reflects fracking recession technical progress off-shoring ofmanufacturing Emissions are likely up since 2017
Emissions
Emissions per person
Itrsquos also interesting to look at the country by country breakdown interms of emissions per capita
IPCC 2007 Mitigation fig SPM3a
As of 2012 US had 454 tons C person and for India this numberwas 046 China was 18(httpcdiacornlgovtrendsemistop2011cap)
Emissions
The problem of stabilizing atmospheric CO2Emissions are about 13Gt C per year
The ocean and biosphere absorb about 45 of emissions (sofar)
This means the ocean and biosphere absorb 13 times 045 asymp 6GtC per year
As a rough guess this means that reducing emissions to 6GtC per year will stabilize atmospheric CO2 (but not climate)
This involves a 55 decrease For an average American thismeans this means reducing emissions from 45 tons per yearto about 20 if US share of total emissions stays constant Ifemissions are allocated equally to each of the worldrsquos 74bpeople then each of us gets 6Gt C 74b people or about 08ton This is an 82 decrease for the average American It isalso about the twice the level of the average Indian and halfthat of the average Chinese
Emissions
Summary
2013 emissions of CO2e were about 49Gt Of this 35Gt wasCO2 and of this about 30Gt from fossil fuels and 5Gt fromland use change and agriculture This is E in our model
Emission are growing rapidly about 2year between 2000and 2010 1970 CO2e was 30Gt
2010 CO2e 14 transport 18 buildings 21 industry 24AFOLU We could use this to calculate refinements of ρ5
The countries responsible for most of the stock are not thecountries responsible for most of the flow
Per capita emissions vary by a factor of about 10 between richand poor countries
There has been a decline in US emissions since 2008 due tofracking recession technical progress off shoring
Peak oil
Will we run out of fossil fuel INot soon enough to matter
0
200
400
600
800
Estimated Reserves
Emissions to Date
Gig
aton
s C
arbo
n
Oil Gas Coal Land Use
EIA
IPCCEIA
IPCC
100
200
300
Em
itted
CO
2 (p
pm)
0
200
400
600
800
We have oceans of coal and lots of oil and these figures predateUS fracking
Peak oil
Will we run out of fossil fuel II
Conclusion
Conclusion I
Here is where we stand with our model
maxIM
u(c1 c2) (14)
st W = c1 + I + M (15)
c2 = (1 + r)I minus γ(T2 minus T1)I (16)
E = (1 minus ρ4MW
)(ρ5(c1 + I)) (17)
P2 = ρ0E + P1 (18)
T2 = ρ1(P2 minus P1) + T1 (19)
We have enough pieces filled in to permit you to calculate theimpact on future climate of particular sorts of current consumptioneg burning a tank of propane on your bbq Wersquoll next start
Conclusion
Conclusion II
thinking about the effect of climate change on production γthough wersquoll make an aside to talk about measurement error first
Conclusion
Conclusion III
Each ppm of atmospheric CO2 corresponds to about 212 Gt C
and 778 Gt of CO2 Pay attention to the units people use
Not all gases are equal in their green house potential CO2 ismost common and most important but other gases are moreimportant per unit of emissions
Over the past 50 years about 55 of each emitted Gt of C
has stayed in the atmosphere The rest has been absorbed byland or oceans Thus it takes about 38 Gt C per 1ppm ofatmospheric CO2
Conclusion
Conclusion IV
Emissions are about 13Gt C for 2013 The rate at whichatmospheric CO2 is increasing has risen from about 1ppmyr1960s to 2ppm for 2000rsquos Since there is lots of fuel weshould expect atmospheric CO2 to continue to increase and atan increasing rate lsquobusiness as usual scenarios call foratmospheric CO2e gt 800 within 100 years
Not all countries are the same They are responsible fordifferent shares have different per capita emissions useemission more or less efficiently and are responsible fordifferent shares of historical emissions These factors are veryimportant obstacles to international agreements and alsosuggest the need for a richer model
Conclusion
Conclusion V
Steady state CO2 emissions are probably very small Sternsuggests less than 13 of current Our calculations suggest(1-055)=45
Carbon cycle
What is lsquoGlobal Warming Potentialrsquo II
Issues
T is completely arbitrary GWP of CH4 for T = 20 100 500 isabout 63 21 9We care about damage not radiative forcing (see Schmalensee The
Energy Journal (1993)) To see this considerIf we anticipate that the world will end in 20 years then neitherCO2 nor CH4 is very harmful but CH4 causes a lot morewarming over that time than CO2If we plan to spend the next 20 years as we do now but then topermanently convert to an economy based on penguinfarming then CH4 emissions now are not very harmful but CO2is (because it is persistent)
We canrsquot really assign relative values to CO2 and CH4 until wesolve for the whole optimal path of emissions for both gasesso any definition of GWP is going to be unsatisfactory
Carbon cycle
Units
Stern 2007 p193 gives CO2e emissions for 2000 as 42Gt CO2e Hansen has 85 Gt C from fossil fuelCan we reconcile these numbers(Yes)
About 77 of CO2e is CO2
About 18 of CO2 is non fossil fuel (more on this later)
Stern reports CO2 Hansen C
so Sternrsquos 42 Gt CO2e becomes42 times (77(1 minus 18))times (1244) = 72 Gt of atmospheric C It would be closer but Stern uses 2000 numbers and Hansenrsquos 85is for about 2008
Atmospheric carbon cycle
Carbon cycle
Carbon is cycled back and forth between the atmosphere oceanand land by biological and chemical processes This means thatemissions donrsquot translate immediately into atmosphericconcentrations Stocksannual flows of C (not CO2 ) are
Atmosphere 800+45Gt
Ocean 40000+3Gt
Volcanos ndash-01Gt
Forests 600-16 Gt
Fossil fuels 5000-85
Sediments ndash-1Gt
Atmospheric carbon cycle
Fossil fuel emissions and deforestation put about 10Gt C in theatmosphere (ca 2007) Atmospheric C increased by about 45GtAbout 3Gt are absorbed by the ocean The remaining 25Gt arethought to be absorbed by plants (NB old numbers to go withfigure) Numbers from Hansen 2009 about the same as in Jacob 1999
Black = natural Red=Anthropogenic AOGCM models of carbon cycle are complicated IPCC 2007 Physical Science basis
figure 73
Atmospheric carbon cycle
Atmospheric CO2 cycle data I
Another way to see this is to look at the relationship betweenemissions and concentration directly
Calculate annual change in C ppm from Mauna Loa (eg)
Calculate annual emissions using emissions rates andconsumption data (more below)
Calculate ratio ∆CO2ppmFossil Fuel emissions = concentration yield of
emissions
Atmospheric carbon cycle
Atmospheric CO2 cycle data II
1950 1960 1970 1980 1990 2000 2010 0
2
4
6
8
10
Global Fossil Fuel CO2 EmissionsCO2 Airborne Fraction (7minusyear mean)
Em
issi
ons
(Gig
aton
s C
yea
r)
0
20
40
60
80
100
Air
born
e Fr
actio
n (
)
Hansen 2009 figure 16
Atmospheric carbon cycle
Atmospheric CO2 cycle data III
So concentration yield of emissions is about 55 Thus
(1055)= 18 Gt C emissions gives 1 Gt ton of atmospheric C
212 Gt atmospheric C to gives 1ppm atmospheric C (or CO2 )
Multiplying 18 times 212 = 38Gt C of emissions to get 1ppm ofatmospheric concentration
Recall the carbon cycle equation from our model
P2 = ρ0E + P1
We have just calculated that ρ0 = 138 = 026ppm C (or CO2 )
Gt C
What is ρ0 if we denominate emissions in terms of CO2
Atmospheric carbon cycle
Atmospheric CO2 cycle data IV
In Hansenrsquos graph the fraction of emissions retained in theatmosphere is CONSTANT as emissions are increasing This isthought to reflect increased absorbtion by plant lsquocarbonfertilizationrsquo or increased lsquonet primary productivityrsquo
In AOGCMrsquos the carbon cycle is modelled very carefully We reallywant to deal with the possibility that absorbtion varies withtemperature or CO2 (it probably does) and there is a lot ofuncertainty about this relationship
Consumption and emissions
Emissions for particular activities I
CO2 from gasoline 23 kgliter = 194 poundsgallon So1000 kg of CO2 emission results from 435 liters or 114gallons of gas (about 1 not burned is mostly N2O so CO2e ishigher)
CO2 from diesel 27 kgliter = 222 poundsgallon 1000 kg ofCO2 emission results from 370 liters or 97 gallons of dieselhttpwwwepagovotaqclimate420f05001htmcalculating
BBQ propane tank about 18 pounds propane = 24kg = 53 lbCO2 (NB Gasoline weighs 63 poundsgallon so 18 poundsof gas gives about 54 pounds CO2 Propane has morehydrogen per carbon atom than gasoline)
Consumption and emissions
Emissions for particular activities II
CO2 sequestration by 1 acre 90 year old pine forest inSoutheastern US is about 100 tons C about 1 tonacreyearSo burning this acre releases about 100 tons C or 367 tonsCO2 httpwwwepagovsequestrationfaqhtml For tropical forests about 18times as much not reliable source
CO2 from coal about 200 tons CO2 per ton (a lot of the stuffin coal is not burned ndash I think) or 2100lb CO2 per 1000 KWHfrom non-baseload coal burning electricity generation CO2eis higher Baseload will usually be lower (often nuclear orhydro) httpwwweiagovtoolsfaqsfaqcfmid=74ampt=11
Consumption and emissions
Emissions for particular activities III
For natural gas about 1200lb CO2 per 1000 KWH Sofracking is fantastic unless too much methane leaks beforeitrsquos burnt With 1 ton of methane worth 23 tons of CO2 about43 leakage makes coal and natural gas even (unless thereis methane leakage from coal mines) The rate of leakage iscurrently contested EPA current estimate is about 06 but05 is probably better (Allen et al PNAS 2013)
For reference Avg household in RI = 500KWHmo Avghousehold in TX = 1000KWHmohttpswwweiagovtoolsfaqsfaqcfmid=97ampt=3 (Feb 2016) Or averagehousehold in Providence sim 8000kwhyear in 2001 Dallas sim18500kwhyear (Glaeser and Kahn JUE 2010)
Consumption and emissions
Emissions for particular activities IV
For thinking about fracking also consider the following
Consumption and emissions
Global emissions per unit of consumption ca 2013
Using these sorts of particular numbers together with informationabout aggregate consumption one can calculate world emissions
Global annual emissions ca 2013 are about 49Gt CO2e or49 times 12
44 sim 133 Gt C (more on this later)
World GDP in 2013 is about 77 trillion USD (NB this is W inour model)
Dividingwe have 133times109 tons C77times1012000USD = 133
7700ton CUSD sim 017 kg C
USD (1 ton= 1000 kg) Multiply by 4412 for CO2 instead of C
Recall the third equation from our global warming model
E = (1 minus ρ4MW
)(ρ5(c1 + I)) (7)
Wersquove just calculated ρ5 Why is this sloppy
Consumption and emissions
Emissions per unit of consumption by countryItrsquos also interesting to look at the country by countrybreakdown(ca 2004) The US and Canada make a lot of stuffper ton of emissions
IPCC 2007 Mitigation fig SPM3b
What if China and Africa made same output at USCAemission rates This is why technology transfer is importantCompare 068 kg CO2e per dollar ca 2004 to my calculationof 017 kg C per dollar 2013 How important is technicalprogress
Consumption and emissions
Technological progress I
httpwww3epagovclimatechangescienceindicatorsghgus-ghg-emissionshtml January 2016
Consumption and emissions
Technological progress II
Nordhaus does this calculation every year country by country
Russia
India
World
EU
US
China
Consumption and emissions
Emissions - Summary
Wersquove now calculated ρ5 emissions per GDP at about 017kgC per dollar ca 2013Looking at the data a little more carefully highlights twodeficiencies on our model
Technological progress is at work so this ratio changes overtimeThere are huge difference across places in this ratio
This highlights the importance of technological progress andtechnology transfer in solving the problem of climate change
Wersquoll address this when we get to the Nordhaus model
Emissions
Emissions trends and levels
Recall
maxIM
u(c1 c2) (8)
st W = c1 + I + M (9)
c2 = (1 + r)I minus γ(T2 minus T1)I (10)
E = (1 minus ρ4MW
)(ρ5(c1 + I)) (11)
P2 = ρ0E + P1 (12)
T2 = ρ1(P2 minus P1) + T1 (13)
Wersquove filled in a bit more The next step is to look at E This meanslooking at trends and levels in CO2 emissions
Emissions
CO2e 1970-2010
IPCC 2013 WG3 fig TS1
Right panel gives confidence bounds for 2010 49Gt CO2e in 2010
Emissions
CO2 by purpose and country income 1750-2010
IPCC 2013 WG3 fig TS2
Emissions
Hansenrsquos version of the same thing
Flow StockHansen 2009 fig 27
Contributions to stock and flow are very different At thenegotiating table developing countries want the right to emit sinceeveryone else had their turn
Emissions
2010 CO2e by purpose
IPCC 2013 WG3 fig TS3
Emissions
2010 CO2e by purpose and country income
IPCC 2013 WG3 fig TS3
Emissions
US 1990-2017 CO2e
ES-4 Inventory of US Greenhouse Gas Emissions and Sinks 1990ndash2017
ES2 Recent Trends in US Greenhouse Gas Emissions and Sinks
In 2017 total gross US greenhouse gas emissions were 64567 MMT or million metric tons of carbon dioxide (CO2) Eq11 Total US emissions have increased by 13 percent from 1990 to 2017 and emissions decreased from 2016 to 2017 by 05 percent (355 MMT CO2 Eq) The decrease in total greenhouse gas emissions between 2016 and 2017 was driven in part by a decrease in CO2 emissions from fossil fuel combustion The decrease in CO2 emissions from fossil fuel combustion was a result of multiple factors including a continued shift from coal to natural gas and increased use of renewable energy in the electric power sector and milder weather that contributed to less overall electricity use
Relative to 1990 the baseline for this Inventory gross emissions in 2017 are higher by 13 percent down from a high of 157 percent above 1990 levels in 2007 Overall net emissions in 2017 were 130 percent below 2005 levels as shown in Table ES-2 Figure ES-1 through Figure ES-3 illustrate the overall trends in total US emissions by gas annual changes and absolute change since 1990 and Table ES-2 provides a detailed summary of gross US greenhouse gas emissions and sinks for 1990 through 2017 Note unless otherwise stated all tables and figures provide total gross emissions and exclude the greenhouse gas fluxes from the Land Use Land-Use Change and Forestry (LULUCF) sector (see Section ES3 Overview of Sector Emissions and Trends)
Figure ES-1 Gross US Greenhouse Gas Emissions by Gas (MMT CO2 Eq)
11 The gross emissions total presented in this report for the United States excludes emissions and removals from Land Use Land-Use Change and Forestry (LULUCF) The net emissions total presented in this report for the United States includes emissions and removals from LULUCF
httpswwwepagovsitesproductionfiles2019-04documentsus-ghg-inventory-2019-main-textpdf September 2019
This reflects fracking recession technical progress off-shoring ofmanufacturing Emissions are likely up since 2017
Emissions
Emissions per person
Itrsquos also interesting to look at the country by country breakdown interms of emissions per capita
IPCC 2007 Mitigation fig SPM3a
As of 2012 US had 454 tons C person and for India this numberwas 046 China was 18(httpcdiacornlgovtrendsemistop2011cap)
Emissions
The problem of stabilizing atmospheric CO2Emissions are about 13Gt C per year
The ocean and biosphere absorb about 45 of emissions (sofar)
This means the ocean and biosphere absorb 13 times 045 asymp 6GtC per year
As a rough guess this means that reducing emissions to 6GtC per year will stabilize atmospheric CO2 (but not climate)
This involves a 55 decrease For an average American thismeans this means reducing emissions from 45 tons per yearto about 20 if US share of total emissions stays constant Ifemissions are allocated equally to each of the worldrsquos 74bpeople then each of us gets 6Gt C 74b people or about 08ton This is an 82 decrease for the average American It isalso about the twice the level of the average Indian and halfthat of the average Chinese
Emissions
Summary
2013 emissions of CO2e were about 49Gt Of this 35Gt wasCO2 and of this about 30Gt from fossil fuels and 5Gt fromland use change and agriculture This is E in our model
Emission are growing rapidly about 2year between 2000and 2010 1970 CO2e was 30Gt
2010 CO2e 14 transport 18 buildings 21 industry 24AFOLU We could use this to calculate refinements of ρ5
The countries responsible for most of the stock are not thecountries responsible for most of the flow
Per capita emissions vary by a factor of about 10 between richand poor countries
There has been a decline in US emissions since 2008 due tofracking recession technical progress off shoring
Peak oil
Will we run out of fossil fuel INot soon enough to matter
0
200
400
600
800
Estimated Reserves
Emissions to Date
Gig
aton
s C
arbo
n
Oil Gas Coal Land Use
EIA
IPCCEIA
IPCC
100
200
300
Em
itted
CO
2 (p
pm)
0
200
400
600
800
We have oceans of coal and lots of oil and these figures predateUS fracking
Peak oil
Will we run out of fossil fuel II
Conclusion
Conclusion I
Here is where we stand with our model
maxIM
u(c1 c2) (14)
st W = c1 + I + M (15)
c2 = (1 + r)I minus γ(T2 minus T1)I (16)
E = (1 minus ρ4MW
)(ρ5(c1 + I)) (17)
P2 = ρ0E + P1 (18)
T2 = ρ1(P2 minus P1) + T1 (19)
We have enough pieces filled in to permit you to calculate theimpact on future climate of particular sorts of current consumptioneg burning a tank of propane on your bbq Wersquoll next start
Conclusion
Conclusion II
thinking about the effect of climate change on production γthough wersquoll make an aside to talk about measurement error first
Conclusion
Conclusion III
Each ppm of atmospheric CO2 corresponds to about 212 Gt C
and 778 Gt of CO2 Pay attention to the units people use
Not all gases are equal in their green house potential CO2 ismost common and most important but other gases are moreimportant per unit of emissions
Over the past 50 years about 55 of each emitted Gt of C
has stayed in the atmosphere The rest has been absorbed byland or oceans Thus it takes about 38 Gt C per 1ppm ofatmospheric CO2
Conclusion
Conclusion IV
Emissions are about 13Gt C for 2013 The rate at whichatmospheric CO2 is increasing has risen from about 1ppmyr1960s to 2ppm for 2000rsquos Since there is lots of fuel weshould expect atmospheric CO2 to continue to increase and atan increasing rate lsquobusiness as usual scenarios call foratmospheric CO2e gt 800 within 100 years
Not all countries are the same They are responsible fordifferent shares have different per capita emissions useemission more or less efficiently and are responsible fordifferent shares of historical emissions These factors are veryimportant obstacles to international agreements and alsosuggest the need for a richer model
Conclusion
Conclusion V
Steady state CO2 emissions are probably very small Sternsuggests less than 13 of current Our calculations suggest(1-055)=45
Carbon cycle
Units
Stern 2007 p193 gives CO2e emissions for 2000 as 42Gt CO2e Hansen has 85 Gt C from fossil fuelCan we reconcile these numbers(Yes)
About 77 of CO2e is CO2
About 18 of CO2 is non fossil fuel (more on this later)
Stern reports CO2 Hansen C
so Sternrsquos 42 Gt CO2e becomes42 times (77(1 minus 18))times (1244) = 72 Gt of atmospheric C It would be closer but Stern uses 2000 numbers and Hansenrsquos 85is for about 2008
Atmospheric carbon cycle
Carbon cycle
Carbon is cycled back and forth between the atmosphere oceanand land by biological and chemical processes This means thatemissions donrsquot translate immediately into atmosphericconcentrations Stocksannual flows of C (not CO2 ) are
Atmosphere 800+45Gt
Ocean 40000+3Gt
Volcanos ndash-01Gt
Forests 600-16 Gt
Fossil fuels 5000-85
Sediments ndash-1Gt
Atmospheric carbon cycle
Fossil fuel emissions and deforestation put about 10Gt C in theatmosphere (ca 2007) Atmospheric C increased by about 45GtAbout 3Gt are absorbed by the ocean The remaining 25Gt arethought to be absorbed by plants (NB old numbers to go withfigure) Numbers from Hansen 2009 about the same as in Jacob 1999
Black = natural Red=Anthropogenic AOGCM models of carbon cycle are complicated IPCC 2007 Physical Science basis
figure 73
Atmospheric carbon cycle
Atmospheric CO2 cycle data I
Another way to see this is to look at the relationship betweenemissions and concentration directly
Calculate annual change in C ppm from Mauna Loa (eg)
Calculate annual emissions using emissions rates andconsumption data (more below)
Calculate ratio ∆CO2ppmFossil Fuel emissions = concentration yield of
emissions
Atmospheric carbon cycle
Atmospheric CO2 cycle data II
1950 1960 1970 1980 1990 2000 2010 0
2
4
6
8
10
Global Fossil Fuel CO2 EmissionsCO2 Airborne Fraction (7minusyear mean)
Em
issi
ons
(Gig
aton
s C
yea
r)
0
20
40
60
80
100
Air
born
e Fr
actio
n (
)
Hansen 2009 figure 16
Atmospheric carbon cycle
Atmospheric CO2 cycle data III
So concentration yield of emissions is about 55 Thus
(1055)= 18 Gt C emissions gives 1 Gt ton of atmospheric C
212 Gt atmospheric C to gives 1ppm atmospheric C (or CO2 )
Multiplying 18 times 212 = 38Gt C of emissions to get 1ppm ofatmospheric concentration
Recall the carbon cycle equation from our model
P2 = ρ0E + P1
We have just calculated that ρ0 = 138 = 026ppm C (or CO2 )
Gt C
What is ρ0 if we denominate emissions in terms of CO2
Atmospheric carbon cycle
Atmospheric CO2 cycle data IV
In Hansenrsquos graph the fraction of emissions retained in theatmosphere is CONSTANT as emissions are increasing This isthought to reflect increased absorbtion by plant lsquocarbonfertilizationrsquo or increased lsquonet primary productivityrsquo
In AOGCMrsquos the carbon cycle is modelled very carefully We reallywant to deal with the possibility that absorbtion varies withtemperature or CO2 (it probably does) and there is a lot ofuncertainty about this relationship
Consumption and emissions
Emissions for particular activities I
CO2 from gasoline 23 kgliter = 194 poundsgallon So1000 kg of CO2 emission results from 435 liters or 114gallons of gas (about 1 not burned is mostly N2O so CO2e ishigher)
CO2 from diesel 27 kgliter = 222 poundsgallon 1000 kg ofCO2 emission results from 370 liters or 97 gallons of dieselhttpwwwepagovotaqclimate420f05001htmcalculating
BBQ propane tank about 18 pounds propane = 24kg = 53 lbCO2 (NB Gasoline weighs 63 poundsgallon so 18 poundsof gas gives about 54 pounds CO2 Propane has morehydrogen per carbon atom than gasoline)
Consumption and emissions
Emissions for particular activities II
CO2 sequestration by 1 acre 90 year old pine forest inSoutheastern US is about 100 tons C about 1 tonacreyearSo burning this acre releases about 100 tons C or 367 tonsCO2 httpwwwepagovsequestrationfaqhtml For tropical forests about 18times as much not reliable source
CO2 from coal about 200 tons CO2 per ton (a lot of the stuffin coal is not burned ndash I think) or 2100lb CO2 per 1000 KWHfrom non-baseload coal burning electricity generation CO2eis higher Baseload will usually be lower (often nuclear orhydro) httpwwweiagovtoolsfaqsfaqcfmid=74ampt=11
Consumption and emissions
Emissions for particular activities III
For natural gas about 1200lb CO2 per 1000 KWH Sofracking is fantastic unless too much methane leaks beforeitrsquos burnt With 1 ton of methane worth 23 tons of CO2 about43 leakage makes coal and natural gas even (unless thereis methane leakage from coal mines) The rate of leakage iscurrently contested EPA current estimate is about 06 but05 is probably better (Allen et al PNAS 2013)
For reference Avg household in RI = 500KWHmo Avghousehold in TX = 1000KWHmohttpswwweiagovtoolsfaqsfaqcfmid=97ampt=3 (Feb 2016) Or averagehousehold in Providence sim 8000kwhyear in 2001 Dallas sim18500kwhyear (Glaeser and Kahn JUE 2010)
Consumption and emissions
Emissions for particular activities IV
For thinking about fracking also consider the following
Consumption and emissions
Global emissions per unit of consumption ca 2013
Using these sorts of particular numbers together with informationabout aggregate consumption one can calculate world emissions
Global annual emissions ca 2013 are about 49Gt CO2e or49 times 12
44 sim 133 Gt C (more on this later)
World GDP in 2013 is about 77 trillion USD (NB this is W inour model)
Dividingwe have 133times109 tons C77times1012000USD = 133
7700ton CUSD sim 017 kg C
USD (1 ton= 1000 kg) Multiply by 4412 for CO2 instead of C
Recall the third equation from our global warming model
E = (1 minus ρ4MW
)(ρ5(c1 + I)) (7)
Wersquove just calculated ρ5 Why is this sloppy
Consumption and emissions
Emissions per unit of consumption by countryItrsquos also interesting to look at the country by countrybreakdown(ca 2004) The US and Canada make a lot of stuffper ton of emissions
IPCC 2007 Mitigation fig SPM3b
What if China and Africa made same output at USCAemission rates This is why technology transfer is importantCompare 068 kg CO2e per dollar ca 2004 to my calculationof 017 kg C per dollar 2013 How important is technicalprogress
Consumption and emissions
Technological progress I
httpwww3epagovclimatechangescienceindicatorsghgus-ghg-emissionshtml January 2016
Consumption and emissions
Technological progress II
Nordhaus does this calculation every year country by country
Russia
India
World
EU
US
China
Consumption and emissions
Emissions - Summary
Wersquove now calculated ρ5 emissions per GDP at about 017kgC per dollar ca 2013Looking at the data a little more carefully highlights twodeficiencies on our model
Technological progress is at work so this ratio changes overtimeThere are huge difference across places in this ratio
This highlights the importance of technological progress andtechnology transfer in solving the problem of climate change
Wersquoll address this when we get to the Nordhaus model
Emissions
Emissions trends and levels
Recall
maxIM
u(c1 c2) (8)
st W = c1 + I + M (9)
c2 = (1 + r)I minus γ(T2 minus T1)I (10)
E = (1 minus ρ4MW
)(ρ5(c1 + I)) (11)
P2 = ρ0E + P1 (12)
T2 = ρ1(P2 minus P1) + T1 (13)
Wersquove filled in a bit more The next step is to look at E This meanslooking at trends and levels in CO2 emissions
Emissions
CO2e 1970-2010
IPCC 2013 WG3 fig TS1
Right panel gives confidence bounds for 2010 49Gt CO2e in 2010
Emissions
CO2 by purpose and country income 1750-2010
IPCC 2013 WG3 fig TS2
Emissions
Hansenrsquos version of the same thing
Flow StockHansen 2009 fig 27
Contributions to stock and flow are very different At thenegotiating table developing countries want the right to emit sinceeveryone else had their turn
Emissions
2010 CO2e by purpose
IPCC 2013 WG3 fig TS3
Emissions
2010 CO2e by purpose and country income
IPCC 2013 WG3 fig TS3
Emissions
US 1990-2017 CO2e
ES-4 Inventory of US Greenhouse Gas Emissions and Sinks 1990ndash2017
ES2 Recent Trends in US Greenhouse Gas Emissions and Sinks
In 2017 total gross US greenhouse gas emissions were 64567 MMT or million metric tons of carbon dioxide (CO2) Eq11 Total US emissions have increased by 13 percent from 1990 to 2017 and emissions decreased from 2016 to 2017 by 05 percent (355 MMT CO2 Eq) The decrease in total greenhouse gas emissions between 2016 and 2017 was driven in part by a decrease in CO2 emissions from fossil fuel combustion The decrease in CO2 emissions from fossil fuel combustion was a result of multiple factors including a continued shift from coal to natural gas and increased use of renewable energy in the electric power sector and milder weather that contributed to less overall electricity use
Relative to 1990 the baseline for this Inventory gross emissions in 2017 are higher by 13 percent down from a high of 157 percent above 1990 levels in 2007 Overall net emissions in 2017 were 130 percent below 2005 levels as shown in Table ES-2 Figure ES-1 through Figure ES-3 illustrate the overall trends in total US emissions by gas annual changes and absolute change since 1990 and Table ES-2 provides a detailed summary of gross US greenhouse gas emissions and sinks for 1990 through 2017 Note unless otherwise stated all tables and figures provide total gross emissions and exclude the greenhouse gas fluxes from the Land Use Land-Use Change and Forestry (LULUCF) sector (see Section ES3 Overview of Sector Emissions and Trends)
Figure ES-1 Gross US Greenhouse Gas Emissions by Gas (MMT CO2 Eq)
11 The gross emissions total presented in this report for the United States excludes emissions and removals from Land Use Land-Use Change and Forestry (LULUCF) The net emissions total presented in this report for the United States includes emissions and removals from LULUCF
httpswwwepagovsitesproductionfiles2019-04documentsus-ghg-inventory-2019-main-textpdf September 2019
This reflects fracking recession technical progress off-shoring ofmanufacturing Emissions are likely up since 2017
Emissions
Emissions per person
Itrsquos also interesting to look at the country by country breakdown interms of emissions per capita
IPCC 2007 Mitigation fig SPM3a
As of 2012 US had 454 tons C person and for India this numberwas 046 China was 18(httpcdiacornlgovtrendsemistop2011cap)
Emissions
The problem of stabilizing atmospheric CO2Emissions are about 13Gt C per year
The ocean and biosphere absorb about 45 of emissions (sofar)
This means the ocean and biosphere absorb 13 times 045 asymp 6GtC per year
As a rough guess this means that reducing emissions to 6GtC per year will stabilize atmospheric CO2 (but not climate)
This involves a 55 decrease For an average American thismeans this means reducing emissions from 45 tons per yearto about 20 if US share of total emissions stays constant Ifemissions are allocated equally to each of the worldrsquos 74bpeople then each of us gets 6Gt C 74b people or about 08ton This is an 82 decrease for the average American It isalso about the twice the level of the average Indian and halfthat of the average Chinese
Emissions
Summary
2013 emissions of CO2e were about 49Gt Of this 35Gt wasCO2 and of this about 30Gt from fossil fuels and 5Gt fromland use change and agriculture This is E in our model
Emission are growing rapidly about 2year between 2000and 2010 1970 CO2e was 30Gt
2010 CO2e 14 transport 18 buildings 21 industry 24AFOLU We could use this to calculate refinements of ρ5
The countries responsible for most of the stock are not thecountries responsible for most of the flow
Per capita emissions vary by a factor of about 10 between richand poor countries
There has been a decline in US emissions since 2008 due tofracking recession technical progress off shoring
Peak oil
Will we run out of fossil fuel INot soon enough to matter
0
200
400
600
800
Estimated Reserves
Emissions to Date
Gig
aton
s C
arbo
n
Oil Gas Coal Land Use
EIA
IPCCEIA
IPCC
100
200
300
Em
itted
CO
2 (p
pm)
0
200
400
600
800
We have oceans of coal and lots of oil and these figures predateUS fracking
Peak oil
Will we run out of fossil fuel II
Conclusion
Conclusion I
Here is where we stand with our model
maxIM
u(c1 c2) (14)
st W = c1 + I + M (15)
c2 = (1 + r)I minus γ(T2 minus T1)I (16)
E = (1 minus ρ4MW
)(ρ5(c1 + I)) (17)
P2 = ρ0E + P1 (18)
T2 = ρ1(P2 minus P1) + T1 (19)
We have enough pieces filled in to permit you to calculate theimpact on future climate of particular sorts of current consumptioneg burning a tank of propane on your bbq Wersquoll next start
Conclusion
Conclusion II
thinking about the effect of climate change on production γthough wersquoll make an aside to talk about measurement error first
Conclusion
Conclusion III
Each ppm of atmospheric CO2 corresponds to about 212 Gt C
and 778 Gt of CO2 Pay attention to the units people use
Not all gases are equal in their green house potential CO2 ismost common and most important but other gases are moreimportant per unit of emissions
Over the past 50 years about 55 of each emitted Gt of C
has stayed in the atmosphere The rest has been absorbed byland or oceans Thus it takes about 38 Gt C per 1ppm ofatmospheric CO2
Conclusion
Conclusion IV
Emissions are about 13Gt C for 2013 The rate at whichatmospheric CO2 is increasing has risen from about 1ppmyr1960s to 2ppm for 2000rsquos Since there is lots of fuel weshould expect atmospheric CO2 to continue to increase and atan increasing rate lsquobusiness as usual scenarios call foratmospheric CO2e gt 800 within 100 years
Not all countries are the same They are responsible fordifferent shares have different per capita emissions useemission more or less efficiently and are responsible fordifferent shares of historical emissions These factors are veryimportant obstacles to international agreements and alsosuggest the need for a richer model
Conclusion
Conclusion V
Steady state CO2 emissions are probably very small Sternsuggests less than 13 of current Our calculations suggest(1-055)=45
Atmospheric carbon cycle
Carbon cycle
Carbon is cycled back and forth between the atmosphere oceanand land by biological and chemical processes This means thatemissions donrsquot translate immediately into atmosphericconcentrations Stocksannual flows of C (not CO2 ) are
Atmosphere 800+45Gt
Ocean 40000+3Gt
Volcanos ndash-01Gt
Forests 600-16 Gt
Fossil fuels 5000-85
Sediments ndash-1Gt
Atmospheric carbon cycle
Fossil fuel emissions and deforestation put about 10Gt C in theatmosphere (ca 2007) Atmospheric C increased by about 45GtAbout 3Gt are absorbed by the ocean The remaining 25Gt arethought to be absorbed by plants (NB old numbers to go withfigure) Numbers from Hansen 2009 about the same as in Jacob 1999
Black = natural Red=Anthropogenic AOGCM models of carbon cycle are complicated IPCC 2007 Physical Science basis
figure 73
Atmospheric carbon cycle
Atmospheric CO2 cycle data I
Another way to see this is to look at the relationship betweenemissions and concentration directly
Calculate annual change in C ppm from Mauna Loa (eg)
Calculate annual emissions using emissions rates andconsumption data (more below)
Calculate ratio ∆CO2ppmFossil Fuel emissions = concentration yield of
emissions
Atmospheric carbon cycle
Atmospheric CO2 cycle data II
1950 1960 1970 1980 1990 2000 2010 0
2
4
6
8
10
Global Fossil Fuel CO2 EmissionsCO2 Airborne Fraction (7minusyear mean)
Em
issi
ons
(Gig
aton
s C
yea
r)
0
20
40
60
80
100
Air
born
e Fr
actio
n (
)
Hansen 2009 figure 16
Atmospheric carbon cycle
Atmospheric CO2 cycle data III
So concentration yield of emissions is about 55 Thus
(1055)= 18 Gt C emissions gives 1 Gt ton of atmospheric C
212 Gt atmospheric C to gives 1ppm atmospheric C (or CO2 )
Multiplying 18 times 212 = 38Gt C of emissions to get 1ppm ofatmospheric concentration
Recall the carbon cycle equation from our model
P2 = ρ0E + P1
We have just calculated that ρ0 = 138 = 026ppm C (or CO2 )
Gt C
What is ρ0 if we denominate emissions in terms of CO2
Atmospheric carbon cycle
Atmospheric CO2 cycle data IV
In Hansenrsquos graph the fraction of emissions retained in theatmosphere is CONSTANT as emissions are increasing This isthought to reflect increased absorbtion by plant lsquocarbonfertilizationrsquo or increased lsquonet primary productivityrsquo
In AOGCMrsquos the carbon cycle is modelled very carefully We reallywant to deal with the possibility that absorbtion varies withtemperature or CO2 (it probably does) and there is a lot ofuncertainty about this relationship
Consumption and emissions
Emissions for particular activities I
CO2 from gasoline 23 kgliter = 194 poundsgallon So1000 kg of CO2 emission results from 435 liters or 114gallons of gas (about 1 not burned is mostly N2O so CO2e ishigher)
CO2 from diesel 27 kgliter = 222 poundsgallon 1000 kg ofCO2 emission results from 370 liters or 97 gallons of dieselhttpwwwepagovotaqclimate420f05001htmcalculating
BBQ propane tank about 18 pounds propane = 24kg = 53 lbCO2 (NB Gasoline weighs 63 poundsgallon so 18 poundsof gas gives about 54 pounds CO2 Propane has morehydrogen per carbon atom than gasoline)
Consumption and emissions
Emissions for particular activities II
CO2 sequestration by 1 acre 90 year old pine forest inSoutheastern US is about 100 tons C about 1 tonacreyearSo burning this acre releases about 100 tons C or 367 tonsCO2 httpwwwepagovsequestrationfaqhtml For tropical forests about 18times as much not reliable source
CO2 from coal about 200 tons CO2 per ton (a lot of the stuffin coal is not burned ndash I think) or 2100lb CO2 per 1000 KWHfrom non-baseload coal burning electricity generation CO2eis higher Baseload will usually be lower (often nuclear orhydro) httpwwweiagovtoolsfaqsfaqcfmid=74ampt=11
Consumption and emissions
Emissions for particular activities III
For natural gas about 1200lb CO2 per 1000 KWH Sofracking is fantastic unless too much methane leaks beforeitrsquos burnt With 1 ton of methane worth 23 tons of CO2 about43 leakage makes coal and natural gas even (unless thereis methane leakage from coal mines) The rate of leakage iscurrently contested EPA current estimate is about 06 but05 is probably better (Allen et al PNAS 2013)
For reference Avg household in RI = 500KWHmo Avghousehold in TX = 1000KWHmohttpswwweiagovtoolsfaqsfaqcfmid=97ampt=3 (Feb 2016) Or averagehousehold in Providence sim 8000kwhyear in 2001 Dallas sim18500kwhyear (Glaeser and Kahn JUE 2010)
Consumption and emissions
Emissions for particular activities IV
For thinking about fracking also consider the following
Consumption and emissions
Global emissions per unit of consumption ca 2013
Using these sorts of particular numbers together with informationabout aggregate consumption one can calculate world emissions
Global annual emissions ca 2013 are about 49Gt CO2e or49 times 12
44 sim 133 Gt C (more on this later)
World GDP in 2013 is about 77 trillion USD (NB this is W inour model)
Dividingwe have 133times109 tons C77times1012000USD = 133
7700ton CUSD sim 017 kg C
USD (1 ton= 1000 kg) Multiply by 4412 for CO2 instead of C
Recall the third equation from our global warming model
E = (1 minus ρ4MW
)(ρ5(c1 + I)) (7)
Wersquove just calculated ρ5 Why is this sloppy
Consumption and emissions
Emissions per unit of consumption by countryItrsquos also interesting to look at the country by countrybreakdown(ca 2004) The US and Canada make a lot of stuffper ton of emissions
IPCC 2007 Mitigation fig SPM3b
What if China and Africa made same output at USCAemission rates This is why technology transfer is importantCompare 068 kg CO2e per dollar ca 2004 to my calculationof 017 kg C per dollar 2013 How important is technicalprogress
Consumption and emissions
Technological progress I
httpwww3epagovclimatechangescienceindicatorsghgus-ghg-emissionshtml January 2016
Consumption and emissions
Technological progress II
Nordhaus does this calculation every year country by country
Russia
India
World
EU
US
China
Consumption and emissions
Emissions - Summary
Wersquove now calculated ρ5 emissions per GDP at about 017kgC per dollar ca 2013Looking at the data a little more carefully highlights twodeficiencies on our model
Technological progress is at work so this ratio changes overtimeThere are huge difference across places in this ratio
This highlights the importance of technological progress andtechnology transfer in solving the problem of climate change
Wersquoll address this when we get to the Nordhaus model
Emissions
Emissions trends and levels
Recall
maxIM
u(c1 c2) (8)
st W = c1 + I + M (9)
c2 = (1 + r)I minus γ(T2 minus T1)I (10)
E = (1 minus ρ4MW
)(ρ5(c1 + I)) (11)
P2 = ρ0E + P1 (12)
T2 = ρ1(P2 minus P1) + T1 (13)
Wersquove filled in a bit more The next step is to look at E This meanslooking at trends and levels in CO2 emissions
Emissions
CO2e 1970-2010
IPCC 2013 WG3 fig TS1
Right panel gives confidence bounds for 2010 49Gt CO2e in 2010
Emissions
CO2 by purpose and country income 1750-2010
IPCC 2013 WG3 fig TS2
Emissions
Hansenrsquos version of the same thing
Flow StockHansen 2009 fig 27
Contributions to stock and flow are very different At thenegotiating table developing countries want the right to emit sinceeveryone else had their turn
Emissions
2010 CO2e by purpose
IPCC 2013 WG3 fig TS3
Emissions
2010 CO2e by purpose and country income
IPCC 2013 WG3 fig TS3
Emissions
US 1990-2017 CO2e
ES-4 Inventory of US Greenhouse Gas Emissions and Sinks 1990ndash2017
ES2 Recent Trends in US Greenhouse Gas Emissions and Sinks
In 2017 total gross US greenhouse gas emissions were 64567 MMT or million metric tons of carbon dioxide (CO2) Eq11 Total US emissions have increased by 13 percent from 1990 to 2017 and emissions decreased from 2016 to 2017 by 05 percent (355 MMT CO2 Eq) The decrease in total greenhouse gas emissions between 2016 and 2017 was driven in part by a decrease in CO2 emissions from fossil fuel combustion The decrease in CO2 emissions from fossil fuel combustion was a result of multiple factors including a continued shift from coal to natural gas and increased use of renewable energy in the electric power sector and milder weather that contributed to less overall electricity use
Relative to 1990 the baseline for this Inventory gross emissions in 2017 are higher by 13 percent down from a high of 157 percent above 1990 levels in 2007 Overall net emissions in 2017 were 130 percent below 2005 levels as shown in Table ES-2 Figure ES-1 through Figure ES-3 illustrate the overall trends in total US emissions by gas annual changes and absolute change since 1990 and Table ES-2 provides a detailed summary of gross US greenhouse gas emissions and sinks for 1990 through 2017 Note unless otherwise stated all tables and figures provide total gross emissions and exclude the greenhouse gas fluxes from the Land Use Land-Use Change and Forestry (LULUCF) sector (see Section ES3 Overview of Sector Emissions and Trends)
Figure ES-1 Gross US Greenhouse Gas Emissions by Gas (MMT CO2 Eq)
11 The gross emissions total presented in this report for the United States excludes emissions and removals from Land Use Land-Use Change and Forestry (LULUCF) The net emissions total presented in this report for the United States includes emissions and removals from LULUCF
httpswwwepagovsitesproductionfiles2019-04documentsus-ghg-inventory-2019-main-textpdf September 2019
This reflects fracking recession technical progress off-shoring ofmanufacturing Emissions are likely up since 2017
Emissions
Emissions per person
Itrsquos also interesting to look at the country by country breakdown interms of emissions per capita
IPCC 2007 Mitigation fig SPM3a
As of 2012 US had 454 tons C person and for India this numberwas 046 China was 18(httpcdiacornlgovtrendsemistop2011cap)
Emissions
The problem of stabilizing atmospheric CO2Emissions are about 13Gt C per year
The ocean and biosphere absorb about 45 of emissions (sofar)
This means the ocean and biosphere absorb 13 times 045 asymp 6GtC per year
As a rough guess this means that reducing emissions to 6GtC per year will stabilize atmospheric CO2 (but not climate)
This involves a 55 decrease For an average American thismeans this means reducing emissions from 45 tons per yearto about 20 if US share of total emissions stays constant Ifemissions are allocated equally to each of the worldrsquos 74bpeople then each of us gets 6Gt C 74b people or about 08ton This is an 82 decrease for the average American It isalso about the twice the level of the average Indian and halfthat of the average Chinese
Emissions
Summary
2013 emissions of CO2e were about 49Gt Of this 35Gt wasCO2 and of this about 30Gt from fossil fuels and 5Gt fromland use change and agriculture This is E in our model
Emission are growing rapidly about 2year between 2000and 2010 1970 CO2e was 30Gt
2010 CO2e 14 transport 18 buildings 21 industry 24AFOLU We could use this to calculate refinements of ρ5
The countries responsible for most of the stock are not thecountries responsible for most of the flow
Per capita emissions vary by a factor of about 10 between richand poor countries
There has been a decline in US emissions since 2008 due tofracking recession technical progress off shoring
Peak oil
Will we run out of fossil fuel INot soon enough to matter
0
200
400
600
800
Estimated Reserves
Emissions to Date
Gig
aton
s C
arbo
n
Oil Gas Coal Land Use
EIA
IPCCEIA
IPCC
100
200
300
Em
itted
CO
2 (p
pm)
0
200
400
600
800
We have oceans of coal and lots of oil and these figures predateUS fracking
Peak oil
Will we run out of fossil fuel II
Conclusion
Conclusion I
Here is where we stand with our model
maxIM
u(c1 c2) (14)
st W = c1 + I + M (15)
c2 = (1 + r)I minus γ(T2 minus T1)I (16)
E = (1 minus ρ4MW
)(ρ5(c1 + I)) (17)
P2 = ρ0E + P1 (18)
T2 = ρ1(P2 minus P1) + T1 (19)
We have enough pieces filled in to permit you to calculate theimpact on future climate of particular sorts of current consumptioneg burning a tank of propane on your bbq Wersquoll next start
Conclusion
Conclusion II
thinking about the effect of climate change on production γthough wersquoll make an aside to talk about measurement error first
Conclusion
Conclusion III
Each ppm of atmospheric CO2 corresponds to about 212 Gt C
and 778 Gt of CO2 Pay attention to the units people use
Not all gases are equal in their green house potential CO2 ismost common and most important but other gases are moreimportant per unit of emissions
Over the past 50 years about 55 of each emitted Gt of C
has stayed in the atmosphere The rest has been absorbed byland or oceans Thus it takes about 38 Gt C per 1ppm ofatmospheric CO2
Conclusion
Conclusion IV
Emissions are about 13Gt C for 2013 The rate at whichatmospheric CO2 is increasing has risen from about 1ppmyr1960s to 2ppm for 2000rsquos Since there is lots of fuel weshould expect atmospheric CO2 to continue to increase and atan increasing rate lsquobusiness as usual scenarios call foratmospheric CO2e gt 800 within 100 years
Not all countries are the same They are responsible fordifferent shares have different per capita emissions useemission more or less efficiently and are responsible fordifferent shares of historical emissions These factors are veryimportant obstacles to international agreements and alsosuggest the need for a richer model
Conclusion
Conclusion V
Steady state CO2 emissions are probably very small Sternsuggests less than 13 of current Our calculations suggest(1-055)=45
Atmospheric carbon cycle
Fossil fuel emissions and deforestation put about 10Gt C in theatmosphere (ca 2007) Atmospheric C increased by about 45GtAbout 3Gt are absorbed by the ocean The remaining 25Gt arethought to be absorbed by plants (NB old numbers to go withfigure) Numbers from Hansen 2009 about the same as in Jacob 1999
Black = natural Red=Anthropogenic AOGCM models of carbon cycle are complicated IPCC 2007 Physical Science basis
figure 73
Atmospheric carbon cycle
Atmospheric CO2 cycle data I
Another way to see this is to look at the relationship betweenemissions and concentration directly
Calculate annual change in C ppm from Mauna Loa (eg)
Calculate annual emissions using emissions rates andconsumption data (more below)
Calculate ratio ∆CO2ppmFossil Fuel emissions = concentration yield of
emissions
Atmospheric carbon cycle
Atmospheric CO2 cycle data II
1950 1960 1970 1980 1990 2000 2010 0
2
4
6
8
10
Global Fossil Fuel CO2 EmissionsCO2 Airborne Fraction (7minusyear mean)
Em
issi
ons
(Gig
aton
s C
yea
r)
0
20
40
60
80
100
Air
born
e Fr
actio
n (
)
Hansen 2009 figure 16
Atmospheric carbon cycle
Atmospheric CO2 cycle data III
So concentration yield of emissions is about 55 Thus
(1055)= 18 Gt C emissions gives 1 Gt ton of atmospheric C
212 Gt atmospheric C to gives 1ppm atmospheric C (or CO2 )
Multiplying 18 times 212 = 38Gt C of emissions to get 1ppm ofatmospheric concentration
Recall the carbon cycle equation from our model
P2 = ρ0E + P1
We have just calculated that ρ0 = 138 = 026ppm C (or CO2 )
Gt C
What is ρ0 if we denominate emissions in terms of CO2
Atmospheric carbon cycle
Atmospheric CO2 cycle data IV
In Hansenrsquos graph the fraction of emissions retained in theatmosphere is CONSTANT as emissions are increasing This isthought to reflect increased absorbtion by plant lsquocarbonfertilizationrsquo or increased lsquonet primary productivityrsquo
In AOGCMrsquos the carbon cycle is modelled very carefully We reallywant to deal with the possibility that absorbtion varies withtemperature or CO2 (it probably does) and there is a lot ofuncertainty about this relationship
Consumption and emissions
Emissions for particular activities I
CO2 from gasoline 23 kgliter = 194 poundsgallon So1000 kg of CO2 emission results from 435 liters or 114gallons of gas (about 1 not burned is mostly N2O so CO2e ishigher)
CO2 from diesel 27 kgliter = 222 poundsgallon 1000 kg ofCO2 emission results from 370 liters or 97 gallons of dieselhttpwwwepagovotaqclimate420f05001htmcalculating
BBQ propane tank about 18 pounds propane = 24kg = 53 lbCO2 (NB Gasoline weighs 63 poundsgallon so 18 poundsof gas gives about 54 pounds CO2 Propane has morehydrogen per carbon atom than gasoline)
Consumption and emissions
Emissions for particular activities II
CO2 sequestration by 1 acre 90 year old pine forest inSoutheastern US is about 100 tons C about 1 tonacreyearSo burning this acre releases about 100 tons C or 367 tonsCO2 httpwwwepagovsequestrationfaqhtml For tropical forests about 18times as much not reliable source
CO2 from coal about 200 tons CO2 per ton (a lot of the stuffin coal is not burned ndash I think) or 2100lb CO2 per 1000 KWHfrom non-baseload coal burning electricity generation CO2eis higher Baseload will usually be lower (often nuclear orhydro) httpwwweiagovtoolsfaqsfaqcfmid=74ampt=11
Consumption and emissions
Emissions for particular activities III
For natural gas about 1200lb CO2 per 1000 KWH Sofracking is fantastic unless too much methane leaks beforeitrsquos burnt With 1 ton of methane worth 23 tons of CO2 about43 leakage makes coal and natural gas even (unless thereis methane leakage from coal mines) The rate of leakage iscurrently contested EPA current estimate is about 06 but05 is probably better (Allen et al PNAS 2013)
For reference Avg household in RI = 500KWHmo Avghousehold in TX = 1000KWHmohttpswwweiagovtoolsfaqsfaqcfmid=97ampt=3 (Feb 2016) Or averagehousehold in Providence sim 8000kwhyear in 2001 Dallas sim18500kwhyear (Glaeser and Kahn JUE 2010)
Consumption and emissions
Emissions for particular activities IV
For thinking about fracking also consider the following
Consumption and emissions
Global emissions per unit of consumption ca 2013
Using these sorts of particular numbers together with informationabout aggregate consumption one can calculate world emissions
Global annual emissions ca 2013 are about 49Gt CO2e or49 times 12
44 sim 133 Gt C (more on this later)
World GDP in 2013 is about 77 trillion USD (NB this is W inour model)
Dividingwe have 133times109 tons C77times1012000USD = 133
7700ton CUSD sim 017 kg C
USD (1 ton= 1000 kg) Multiply by 4412 for CO2 instead of C
Recall the third equation from our global warming model
E = (1 minus ρ4MW
)(ρ5(c1 + I)) (7)
Wersquove just calculated ρ5 Why is this sloppy
Consumption and emissions
Emissions per unit of consumption by countryItrsquos also interesting to look at the country by countrybreakdown(ca 2004) The US and Canada make a lot of stuffper ton of emissions
IPCC 2007 Mitigation fig SPM3b
What if China and Africa made same output at USCAemission rates This is why technology transfer is importantCompare 068 kg CO2e per dollar ca 2004 to my calculationof 017 kg C per dollar 2013 How important is technicalprogress
Consumption and emissions
Technological progress I
httpwww3epagovclimatechangescienceindicatorsghgus-ghg-emissionshtml January 2016
Consumption and emissions
Technological progress II
Nordhaus does this calculation every year country by country
Russia
India
World
EU
US
China
Consumption and emissions
Emissions - Summary
Wersquove now calculated ρ5 emissions per GDP at about 017kgC per dollar ca 2013Looking at the data a little more carefully highlights twodeficiencies on our model
Technological progress is at work so this ratio changes overtimeThere are huge difference across places in this ratio
This highlights the importance of technological progress andtechnology transfer in solving the problem of climate change
Wersquoll address this when we get to the Nordhaus model
Emissions
Emissions trends and levels
Recall
maxIM
u(c1 c2) (8)
st W = c1 + I + M (9)
c2 = (1 + r)I minus γ(T2 minus T1)I (10)
E = (1 minus ρ4MW
)(ρ5(c1 + I)) (11)
P2 = ρ0E + P1 (12)
T2 = ρ1(P2 minus P1) + T1 (13)
Wersquove filled in a bit more The next step is to look at E This meanslooking at trends and levels in CO2 emissions
Emissions
CO2e 1970-2010
IPCC 2013 WG3 fig TS1
Right panel gives confidence bounds for 2010 49Gt CO2e in 2010
Emissions
CO2 by purpose and country income 1750-2010
IPCC 2013 WG3 fig TS2
Emissions
Hansenrsquos version of the same thing
Flow StockHansen 2009 fig 27
Contributions to stock and flow are very different At thenegotiating table developing countries want the right to emit sinceeveryone else had their turn
Emissions
2010 CO2e by purpose
IPCC 2013 WG3 fig TS3
Emissions
2010 CO2e by purpose and country income
IPCC 2013 WG3 fig TS3
Emissions
US 1990-2017 CO2e
ES-4 Inventory of US Greenhouse Gas Emissions and Sinks 1990ndash2017
ES2 Recent Trends in US Greenhouse Gas Emissions and Sinks
In 2017 total gross US greenhouse gas emissions were 64567 MMT or million metric tons of carbon dioxide (CO2) Eq11 Total US emissions have increased by 13 percent from 1990 to 2017 and emissions decreased from 2016 to 2017 by 05 percent (355 MMT CO2 Eq) The decrease in total greenhouse gas emissions between 2016 and 2017 was driven in part by a decrease in CO2 emissions from fossil fuel combustion The decrease in CO2 emissions from fossil fuel combustion was a result of multiple factors including a continued shift from coal to natural gas and increased use of renewable energy in the electric power sector and milder weather that contributed to less overall electricity use
Relative to 1990 the baseline for this Inventory gross emissions in 2017 are higher by 13 percent down from a high of 157 percent above 1990 levels in 2007 Overall net emissions in 2017 were 130 percent below 2005 levels as shown in Table ES-2 Figure ES-1 through Figure ES-3 illustrate the overall trends in total US emissions by gas annual changes and absolute change since 1990 and Table ES-2 provides a detailed summary of gross US greenhouse gas emissions and sinks for 1990 through 2017 Note unless otherwise stated all tables and figures provide total gross emissions and exclude the greenhouse gas fluxes from the Land Use Land-Use Change and Forestry (LULUCF) sector (see Section ES3 Overview of Sector Emissions and Trends)
Figure ES-1 Gross US Greenhouse Gas Emissions by Gas (MMT CO2 Eq)
11 The gross emissions total presented in this report for the United States excludes emissions and removals from Land Use Land-Use Change and Forestry (LULUCF) The net emissions total presented in this report for the United States includes emissions and removals from LULUCF
httpswwwepagovsitesproductionfiles2019-04documentsus-ghg-inventory-2019-main-textpdf September 2019
This reflects fracking recession technical progress off-shoring ofmanufacturing Emissions are likely up since 2017
Emissions
Emissions per person
Itrsquos also interesting to look at the country by country breakdown interms of emissions per capita
IPCC 2007 Mitigation fig SPM3a
As of 2012 US had 454 tons C person and for India this numberwas 046 China was 18(httpcdiacornlgovtrendsemistop2011cap)
Emissions
The problem of stabilizing atmospheric CO2Emissions are about 13Gt C per year
The ocean and biosphere absorb about 45 of emissions (sofar)
This means the ocean and biosphere absorb 13 times 045 asymp 6GtC per year
As a rough guess this means that reducing emissions to 6GtC per year will stabilize atmospheric CO2 (but not climate)
This involves a 55 decrease For an average American thismeans this means reducing emissions from 45 tons per yearto about 20 if US share of total emissions stays constant Ifemissions are allocated equally to each of the worldrsquos 74bpeople then each of us gets 6Gt C 74b people or about 08ton This is an 82 decrease for the average American It isalso about the twice the level of the average Indian and halfthat of the average Chinese
Emissions
Summary
2013 emissions of CO2e were about 49Gt Of this 35Gt wasCO2 and of this about 30Gt from fossil fuels and 5Gt fromland use change and agriculture This is E in our model
Emission are growing rapidly about 2year between 2000and 2010 1970 CO2e was 30Gt
2010 CO2e 14 transport 18 buildings 21 industry 24AFOLU We could use this to calculate refinements of ρ5
The countries responsible for most of the stock are not thecountries responsible for most of the flow
Per capita emissions vary by a factor of about 10 between richand poor countries
There has been a decline in US emissions since 2008 due tofracking recession technical progress off shoring
Peak oil
Will we run out of fossil fuel INot soon enough to matter
0
200
400
600
800
Estimated Reserves
Emissions to Date
Gig
aton
s C
arbo
n
Oil Gas Coal Land Use
EIA
IPCCEIA
IPCC
100
200
300
Em
itted
CO
2 (p
pm)
0
200
400
600
800
We have oceans of coal and lots of oil and these figures predateUS fracking
Peak oil
Will we run out of fossil fuel II
Conclusion
Conclusion I
Here is where we stand with our model
maxIM
u(c1 c2) (14)
st W = c1 + I + M (15)
c2 = (1 + r)I minus γ(T2 minus T1)I (16)
E = (1 minus ρ4MW
)(ρ5(c1 + I)) (17)
P2 = ρ0E + P1 (18)
T2 = ρ1(P2 minus P1) + T1 (19)
We have enough pieces filled in to permit you to calculate theimpact on future climate of particular sorts of current consumptioneg burning a tank of propane on your bbq Wersquoll next start
Conclusion
Conclusion II
thinking about the effect of climate change on production γthough wersquoll make an aside to talk about measurement error first
Conclusion
Conclusion III
Each ppm of atmospheric CO2 corresponds to about 212 Gt C
and 778 Gt of CO2 Pay attention to the units people use
Not all gases are equal in their green house potential CO2 ismost common and most important but other gases are moreimportant per unit of emissions
Over the past 50 years about 55 of each emitted Gt of C
has stayed in the atmosphere The rest has been absorbed byland or oceans Thus it takes about 38 Gt C per 1ppm ofatmospheric CO2
Conclusion
Conclusion IV
Emissions are about 13Gt C for 2013 The rate at whichatmospheric CO2 is increasing has risen from about 1ppmyr1960s to 2ppm for 2000rsquos Since there is lots of fuel weshould expect atmospheric CO2 to continue to increase and atan increasing rate lsquobusiness as usual scenarios call foratmospheric CO2e gt 800 within 100 years
Not all countries are the same They are responsible fordifferent shares have different per capita emissions useemission more or less efficiently and are responsible fordifferent shares of historical emissions These factors are veryimportant obstacles to international agreements and alsosuggest the need for a richer model
Conclusion
Conclusion V
Steady state CO2 emissions are probably very small Sternsuggests less than 13 of current Our calculations suggest(1-055)=45
Atmospheric carbon cycle
Atmospheric CO2 cycle data I
Another way to see this is to look at the relationship betweenemissions and concentration directly
Calculate annual change in C ppm from Mauna Loa (eg)
Calculate annual emissions using emissions rates andconsumption data (more below)
Calculate ratio ∆CO2ppmFossil Fuel emissions = concentration yield of
emissions
Atmospheric carbon cycle
Atmospheric CO2 cycle data II
1950 1960 1970 1980 1990 2000 2010 0
2
4
6
8
10
Global Fossil Fuel CO2 EmissionsCO2 Airborne Fraction (7minusyear mean)
Em
issi
ons
(Gig
aton
s C
yea
r)
0
20
40
60
80
100
Air
born
e Fr
actio
n (
)
Hansen 2009 figure 16
Atmospheric carbon cycle
Atmospheric CO2 cycle data III
So concentration yield of emissions is about 55 Thus
(1055)= 18 Gt C emissions gives 1 Gt ton of atmospheric C
212 Gt atmospheric C to gives 1ppm atmospheric C (or CO2 )
Multiplying 18 times 212 = 38Gt C of emissions to get 1ppm ofatmospheric concentration
Recall the carbon cycle equation from our model
P2 = ρ0E + P1
We have just calculated that ρ0 = 138 = 026ppm C (or CO2 )
Gt C
What is ρ0 if we denominate emissions in terms of CO2
Atmospheric carbon cycle
Atmospheric CO2 cycle data IV
In Hansenrsquos graph the fraction of emissions retained in theatmosphere is CONSTANT as emissions are increasing This isthought to reflect increased absorbtion by plant lsquocarbonfertilizationrsquo or increased lsquonet primary productivityrsquo
In AOGCMrsquos the carbon cycle is modelled very carefully We reallywant to deal with the possibility that absorbtion varies withtemperature or CO2 (it probably does) and there is a lot ofuncertainty about this relationship
Consumption and emissions
Emissions for particular activities I
CO2 from gasoline 23 kgliter = 194 poundsgallon So1000 kg of CO2 emission results from 435 liters or 114gallons of gas (about 1 not burned is mostly N2O so CO2e ishigher)
CO2 from diesel 27 kgliter = 222 poundsgallon 1000 kg ofCO2 emission results from 370 liters or 97 gallons of dieselhttpwwwepagovotaqclimate420f05001htmcalculating
BBQ propane tank about 18 pounds propane = 24kg = 53 lbCO2 (NB Gasoline weighs 63 poundsgallon so 18 poundsof gas gives about 54 pounds CO2 Propane has morehydrogen per carbon atom than gasoline)
Consumption and emissions
Emissions for particular activities II
CO2 sequestration by 1 acre 90 year old pine forest inSoutheastern US is about 100 tons C about 1 tonacreyearSo burning this acre releases about 100 tons C or 367 tonsCO2 httpwwwepagovsequestrationfaqhtml For tropical forests about 18times as much not reliable source
CO2 from coal about 200 tons CO2 per ton (a lot of the stuffin coal is not burned ndash I think) or 2100lb CO2 per 1000 KWHfrom non-baseload coal burning electricity generation CO2eis higher Baseload will usually be lower (often nuclear orhydro) httpwwweiagovtoolsfaqsfaqcfmid=74ampt=11
Consumption and emissions
Emissions for particular activities III
For natural gas about 1200lb CO2 per 1000 KWH Sofracking is fantastic unless too much methane leaks beforeitrsquos burnt With 1 ton of methane worth 23 tons of CO2 about43 leakage makes coal and natural gas even (unless thereis methane leakage from coal mines) The rate of leakage iscurrently contested EPA current estimate is about 06 but05 is probably better (Allen et al PNAS 2013)
For reference Avg household in RI = 500KWHmo Avghousehold in TX = 1000KWHmohttpswwweiagovtoolsfaqsfaqcfmid=97ampt=3 (Feb 2016) Or averagehousehold in Providence sim 8000kwhyear in 2001 Dallas sim18500kwhyear (Glaeser and Kahn JUE 2010)
Consumption and emissions
Emissions for particular activities IV
For thinking about fracking also consider the following
Consumption and emissions
Global emissions per unit of consumption ca 2013
Using these sorts of particular numbers together with informationabout aggregate consumption one can calculate world emissions
Global annual emissions ca 2013 are about 49Gt CO2e or49 times 12
44 sim 133 Gt C (more on this later)
World GDP in 2013 is about 77 trillion USD (NB this is W inour model)
Dividingwe have 133times109 tons C77times1012000USD = 133
7700ton CUSD sim 017 kg C
USD (1 ton= 1000 kg) Multiply by 4412 for CO2 instead of C
Recall the third equation from our global warming model
E = (1 minus ρ4MW
)(ρ5(c1 + I)) (7)
Wersquove just calculated ρ5 Why is this sloppy
Consumption and emissions
Emissions per unit of consumption by countryItrsquos also interesting to look at the country by countrybreakdown(ca 2004) The US and Canada make a lot of stuffper ton of emissions
IPCC 2007 Mitigation fig SPM3b
What if China and Africa made same output at USCAemission rates This is why technology transfer is importantCompare 068 kg CO2e per dollar ca 2004 to my calculationof 017 kg C per dollar 2013 How important is technicalprogress
Consumption and emissions
Technological progress I
httpwww3epagovclimatechangescienceindicatorsghgus-ghg-emissionshtml January 2016
Consumption and emissions
Technological progress II
Nordhaus does this calculation every year country by country
Russia
India
World
EU
US
China
Consumption and emissions
Emissions - Summary
Wersquove now calculated ρ5 emissions per GDP at about 017kgC per dollar ca 2013Looking at the data a little more carefully highlights twodeficiencies on our model
Technological progress is at work so this ratio changes overtimeThere are huge difference across places in this ratio
This highlights the importance of technological progress andtechnology transfer in solving the problem of climate change
Wersquoll address this when we get to the Nordhaus model
Emissions
Emissions trends and levels
Recall
maxIM
u(c1 c2) (8)
st W = c1 + I + M (9)
c2 = (1 + r)I minus γ(T2 minus T1)I (10)
E = (1 minus ρ4MW
)(ρ5(c1 + I)) (11)
P2 = ρ0E + P1 (12)
T2 = ρ1(P2 minus P1) + T1 (13)
Wersquove filled in a bit more The next step is to look at E This meanslooking at trends and levels in CO2 emissions
Emissions
CO2e 1970-2010
IPCC 2013 WG3 fig TS1
Right panel gives confidence bounds for 2010 49Gt CO2e in 2010
Emissions
CO2 by purpose and country income 1750-2010
IPCC 2013 WG3 fig TS2
Emissions
Hansenrsquos version of the same thing
Flow StockHansen 2009 fig 27
Contributions to stock and flow are very different At thenegotiating table developing countries want the right to emit sinceeveryone else had their turn
Emissions
2010 CO2e by purpose
IPCC 2013 WG3 fig TS3
Emissions
2010 CO2e by purpose and country income
IPCC 2013 WG3 fig TS3
Emissions
US 1990-2017 CO2e
ES-4 Inventory of US Greenhouse Gas Emissions and Sinks 1990ndash2017
ES2 Recent Trends in US Greenhouse Gas Emissions and Sinks
In 2017 total gross US greenhouse gas emissions were 64567 MMT or million metric tons of carbon dioxide (CO2) Eq11 Total US emissions have increased by 13 percent from 1990 to 2017 and emissions decreased from 2016 to 2017 by 05 percent (355 MMT CO2 Eq) The decrease in total greenhouse gas emissions between 2016 and 2017 was driven in part by a decrease in CO2 emissions from fossil fuel combustion The decrease in CO2 emissions from fossil fuel combustion was a result of multiple factors including a continued shift from coal to natural gas and increased use of renewable energy in the electric power sector and milder weather that contributed to less overall electricity use
Relative to 1990 the baseline for this Inventory gross emissions in 2017 are higher by 13 percent down from a high of 157 percent above 1990 levels in 2007 Overall net emissions in 2017 were 130 percent below 2005 levels as shown in Table ES-2 Figure ES-1 through Figure ES-3 illustrate the overall trends in total US emissions by gas annual changes and absolute change since 1990 and Table ES-2 provides a detailed summary of gross US greenhouse gas emissions and sinks for 1990 through 2017 Note unless otherwise stated all tables and figures provide total gross emissions and exclude the greenhouse gas fluxes from the Land Use Land-Use Change and Forestry (LULUCF) sector (see Section ES3 Overview of Sector Emissions and Trends)
Figure ES-1 Gross US Greenhouse Gas Emissions by Gas (MMT CO2 Eq)
11 The gross emissions total presented in this report for the United States excludes emissions and removals from Land Use Land-Use Change and Forestry (LULUCF) The net emissions total presented in this report for the United States includes emissions and removals from LULUCF
httpswwwepagovsitesproductionfiles2019-04documentsus-ghg-inventory-2019-main-textpdf September 2019
This reflects fracking recession technical progress off-shoring ofmanufacturing Emissions are likely up since 2017
Emissions
Emissions per person
Itrsquos also interesting to look at the country by country breakdown interms of emissions per capita
IPCC 2007 Mitigation fig SPM3a
As of 2012 US had 454 tons C person and for India this numberwas 046 China was 18(httpcdiacornlgovtrendsemistop2011cap)
Emissions
The problem of stabilizing atmospheric CO2Emissions are about 13Gt C per year
The ocean and biosphere absorb about 45 of emissions (sofar)
This means the ocean and biosphere absorb 13 times 045 asymp 6GtC per year
As a rough guess this means that reducing emissions to 6GtC per year will stabilize atmospheric CO2 (but not climate)
This involves a 55 decrease For an average American thismeans this means reducing emissions from 45 tons per yearto about 20 if US share of total emissions stays constant Ifemissions are allocated equally to each of the worldrsquos 74bpeople then each of us gets 6Gt C 74b people or about 08ton This is an 82 decrease for the average American It isalso about the twice the level of the average Indian and halfthat of the average Chinese
Emissions
Summary
2013 emissions of CO2e were about 49Gt Of this 35Gt wasCO2 and of this about 30Gt from fossil fuels and 5Gt fromland use change and agriculture This is E in our model
Emission are growing rapidly about 2year between 2000and 2010 1970 CO2e was 30Gt
2010 CO2e 14 transport 18 buildings 21 industry 24AFOLU We could use this to calculate refinements of ρ5
The countries responsible for most of the stock are not thecountries responsible for most of the flow
Per capita emissions vary by a factor of about 10 between richand poor countries
There has been a decline in US emissions since 2008 due tofracking recession technical progress off shoring
Peak oil
Will we run out of fossil fuel INot soon enough to matter
0
200
400
600
800
Estimated Reserves
Emissions to Date
Gig
aton
s C
arbo
n
Oil Gas Coal Land Use
EIA
IPCCEIA
IPCC
100
200
300
Em
itted
CO
2 (p
pm)
0
200
400
600
800
We have oceans of coal and lots of oil and these figures predateUS fracking
Peak oil
Will we run out of fossil fuel II
Conclusion
Conclusion I
Here is where we stand with our model
maxIM
u(c1 c2) (14)
st W = c1 + I + M (15)
c2 = (1 + r)I minus γ(T2 minus T1)I (16)
E = (1 minus ρ4MW
)(ρ5(c1 + I)) (17)
P2 = ρ0E + P1 (18)
T2 = ρ1(P2 minus P1) + T1 (19)
We have enough pieces filled in to permit you to calculate theimpact on future climate of particular sorts of current consumptioneg burning a tank of propane on your bbq Wersquoll next start
Conclusion
Conclusion II
thinking about the effect of climate change on production γthough wersquoll make an aside to talk about measurement error first
Conclusion
Conclusion III
Each ppm of atmospheric CO2 corresponds to about 212 Gt C
and 778 Gt of CO2 Pay attention to the units people use
Not all gases are equal in their green house potential CO2 ismost common and most important but other gases are moreimportant per unit of emissions
Over the past 50 years about 55 of each emitted Gt of C
has stayed in the atmosphere The rest has been absorbed byland or oceans Thus it takes about 38 Gt C per 1ppm ofatmospheric CO2
Conclusion
Conclusion IV
Emissions are about 13Gt C for 2013 The rate at whichatmospheric CO2 is increasing has risen from about 1ppmyr1960s to 2ppm for 2000rsquos Since there is lots of fuel weshould expect atmospheric CO2 to continue to increase and atan increasing rate lsquobusiness as usual scenarios call foratmospheric CO2e gt 800 within 100 years
Not all countries are the same They are responsible fordifferent shares have different per capita emissions useemission more or less efficiently and are responsible fordifferent shares of historical emissions These factors are veryimportant obstacles to international agreements and alsosuggest the need for a richer model
Conclusion
Conclusion V
Steady state CO2 emissions are probably very small Sternsuggests less than 13 of current Our calculations suggest(1-055)=45
Atmospheric carbon cycle
Atmospheric CO2 cycle data II
1950 1960 1970 1980 1990 2000 2010 0
2
4
6
8
10
Global Fossil Fuel CO2 EmissionsCO2 Airborne Fraction (7minusyear mean)
Em
issi
ons
(Gig
aton
s C
yea
r)
0
20
40
60
80
100
Air
born
e Fr
actio
n (
)
Hansen 2009 figure 16
Atmospheric carbon cycle
Atmospheric CO2 cycle data III
So concentration yield of emissions is about 55 Thus
(1055)= 18 Gt C emissions gives 1 Gt ton of atmospheric C
212 Gt atmospheric C to gives 1ppm atmospheric C (or CO2 )
Multiplying 18 times 212 = 38Gt C of emissions to get 1ppm ofatmospheric concentration
Recall the carbon cycle equation from our model
P2 = ρ0E + P1
We have just calculated that ρ0 = 138 = 026ppm C (or CO2 )
Gt C
What is ρ0 if we denominate emissions in terms of CO2
Atmospheric carbon cycle
Atmospheric CO2 cycle data IV
In Hansenrsquos graph the fraction of emissions retained in theatmosphere is CONSTANT as emissions are increasing This isthought to reflect increased absorbtion by plant lsquocarbonfertilizationrsquo or increased lsquonet primary productivityrsquo
In AOGCMrsquos the carbon cycle is modelled very carefully We reallywant to deal with the possibility that absorbtion varies withtemperature or CO2 (it probably does) and there is a lot ofuncertainty about this relationship
Consumption and emissions
Emissions for particular activities I
CO2 from gasoline 23 kgliter = 194 poundsgallon So1000 kg of CO2 emission results from 435 liters or 114gallons of gas (about 1 not burned is mostly N2O so CO2e ishigher)
CO2 from diesel 27 kgliter = 222 poundsgallon 1000 kg ofCO2 emission results from 370 liters or 97 gallons of dieselhttpwwwepagovotaqclimate420f05001htmcalculating
BBQ propane tank about 18 pounds propane = 24kg = 53 lbCO2 (NB Gasoline weighs 63 poundsgallon so 18 poundsof gas gives about 54 pounds CO2 Propane has morehydrogen per carbon atom than gasoline)
Consumption and emissions
Emissions for particular activities II
CO2 sequestration by 1 acre 90 year old pine forest inSoutheastern US is about 100 tons C about 1 tonacreyearSo burning this acre releases about 100 tons C or 367 tonsCO2 httpwwwepagovsequestrationfaqhtml For tropical forests about 18times as much not reliable source
CO2 from coal about 200 tons CO2 per ton (a lot of the stuffin coal is not burned ndash I think) or 2100lb CO2 per 1000 KWHfrom non-baseload coal burning electricity generation CO2eis higher Baseload will usually be lower (often nuclear orhydro) httpwwweiagovtoolsfaqsfaqcfmid=74ampt=11
Consumption and emissions
Emissions for particular activities III
For natural gas about 1200lb CO2 per 1000 KWH Sofracking is fantastic unless too much methane leaks beforeitrsquos burnt With 1 ton of methane worth 23 tons of CO2 about43 leakage makes coal and natural gas even (unless thereis methane leakage from coal mines) The rate of leakage iscurrently contested EPA current estimate is about 06 but05 is probably better (Allen et al PNAS 2013)
For reference Avg household in RI = 500KWHmo Avghousehold in TX = 1000KWHmohttpswwweiagovtoolsfaqsfaqcfmid=97ampt=3 (Feb 2016) Or averagehousehold in Providence sim 8000kwhyear in 2001 Dallas sim18500kwhyear (Glaeser and Kahn JUE 2010)
Consumption and emissions
Emissions for particular activities IV
For thinking about fracking also consider the following
Consumption and emissions
Global emissions per unit of consumption ca 2013
Using these sorts of particular numbers together with informationabout aggregate consumption one can calculate world emissions
Global annual emissions ca 2013 are about 49Gt CO2e or49 times 12
44 sim 133 Gt C (more on this later)
World GDP in 2013 is about 77 trillion USD (NB this is W inour model)
Dividingwe have 133times109 tons C77times1012000USD = 133
7700ton CUSD sim 017 kg C
USD (1 ton= 1000 kg) Multiply by 4412 for CO2 instead of C
Recall the third equation from our global warming model
E = (1 minus ρ4MW
)(ρ5(c1 + I)) (7)
Wersquove just calculated ρ5 Why is this sloppy
Consumption and emissions
Emissions per unit of consumption by countryItrsquos also interesting to look at the country by countrybreakdown(ca 2004) The US and Canada make a lot of stuffper ton of emissions
IPCC 2007 Mitigation fig SPM3b
What if China and Africa made same output at USCAemission rates This is why technology transfer is importantCompare 068 kg CO2e per dollar ca 2004 to my calculationof 017 kg C per dollar 2013 How important is technicalprogress
Consumption and emissions
Technological progress I
httpwww3epagovclimatechangescienceindicatorsghgus-ghg-emissionshtml January 2016
Consumption and emissions
Technological progress II
Nordhaus does this calculation every year country by country
Russia
India
World
EU
US
China
Consumption and emissions
Emissions - Summary
Wersquove now calculated ρ5 emissions per GDP at about 017kgC per dollar ca 2013Looking at the data a little more carefully highlights twodeficiencies on our model
Technological progress is at work so this ratio changes overtimeThere are huge difference across places in this ratio
This highlights the importance of technological progress andtechnology transfer in solving the problem of climate change
Wersquoll address this when we get to the Nordhaus model
Emissions
Emissions trends and levels
Recall
maxIM
u(c1 c2) (8)
st W = c1 + I + M (9)
c2 = (1 + r)I minus γ(T2 minus T1)I (10)
E = (1 minus ρ4MW
)(ρ5(c1 + I)) (11)
P2 = ρ0E + P1 (12)
T2 = ρ1(P2 minus P1) + T1 (13)
Wersquove filled in a bit more The next step is to look at E This meanslooking at trends and levels in CO2 emissions
Emissions
CO2e 1970-2010
IPCC 2013 WG3 fig TS1
Right panel gives confidence bounds for 2010 49Gt CO2e in 2010
Emissions
CO2 by purpose and country income 1750-2010
IPCC 2013 WG3 fig TS2
Emissions
Hansenrsquos version of the same thing
Flow StockHansen 2009 fig 27
Contributions to stock and flow are very different At thenegotiating table developing countries want the right to emit sinceeveryone else had their turn
Emissions
2010 CO2e by purpose
IPCC 2013 WG3 fig TS3
Emissions
2010 CO2e by purpose and country income
IPCC 2013 WG3 fig TS3
Emissions
US 1990-2017 CO2e
ES-4 Inventory of US Greenhouse Gas Emissions and Sinks 1990ndash2017
ES2 Recent Trends in US Greenhouse Gas Emissions and Sinks
In 2017 total gross US greenhouse gas emissions were 64567 MMT or million metric tons of carbon dioxide (CO2) Eq11 Total US emissions have increased by 13 percent from 1990 to 2017 and emissions decreased from 2016 to 2017 by 05 percent (355 MMT CO2 Eq) The decrease in total greenhouse gas emissions between 2016 and 2017 was driven in part by a decrease in CO2 emissions from fossil fuel combustion The decrease in CO2 emissions from fossil fuel combustion was a result of multiple factors including a continued shift from coal to natural gas and increased use of renewable energy in the electric power sector and milder weather that contributed to less overall electricity use
Relative to 1990 the baseline for this Inventory gross emissions in 2017 are higher by 13 percent down from a high of 157 percent above 1990 levels in 2007 Overall net emissions in 2017 were 130 percent below 2005 levels as shown in Table ES-2 Figure ES-1 through Figure ES-3 illustrate the overall trends in total US emissions by gas annual changes and absolute change since 1990 and Table ES-2 provides a detailed summary of gross US greenhouse gas emissions and sinks for 1990 through 2017 Note unless otherwise stated all tables and figures provide total gross emissions and exclude the greenhouse gas fluxes from the Land Use Land-Use Change and Forestry (LULUCF) sector (see Section ES3 Overview of Sector Emissions and Trends)
Figure ES-1 Gross US Greenhouse Gas Emissions by Gas (MMT CO2 Eq)
11 The gross emissions total presented in this report for the United States excludes emissions and removals from Land Use Land-Use Change and Forestry (LULUCF) The net emissions total presented in this report for the United States includes emissions and removals from LULUCF
httpswwwepagovsitesproductionfiles2019-04documentsus-ghg-inventory-2019-main-textpdf September 2019
This reflects fracking recession technical progress off-shoring ofmanufacturing Emissions are likely up since 2017
Emissions
Emissions per person
Itrsquos also interesting to look at the country by country breakdown interms of emissions per capita
IPCC 2007 Mitigation fig SPM3a
As of 2012 US had 454 tons C person and for India this numberwas 046 China was 18(httpcdiacornlgovtrendsemistop2011cap)
Emissions
The problem of stabilizing atmospheric CO2Emissions are about 13Gt C per year
The ocean and biosphere absorb about 45 of emissions (sofar)
This means the ocean and biosphere absorb 13 times 045 asymp 6GtC per year
As a rough guess this means that reducing emissions to 6GtC per year will stabilize atmospheric CO2 (but not climate)
This involves a 55 decrease For an average American thismeans this means reducing emissions from 45 tons per yearto about 20 if US share of total emissions stays constant Ifemissions are allocated equally to each of the worldrsquos 74bpeople then each of us gets 6Gt C 74b people or about 08ton This is an 82 decrease for the average American It isalso about the twice the level of the average Indian and halfthat of the average Chinese
Emissions
Summary
2013 emissions of CO2e were about 49Gt Of this 35Gt wasCO2 and of this about 30Gt from fossil fuels and 5Gt fromland use change and agriculture This is E in our model
Emission are growing rapidly about 2year between 2000and 2010 1970 CO2e was 30Gt
2010 CO2e 14 transport 18 buildings 21 industry 24AFOLU We could use this to calculate refinements of ρ5
The countries responsible for most of the stock are not thecountries responsible for most of the flow
Per capita emissions vary by a factor of about 10 between richand poor countries
There has been a decline in US emissions since 2008 due tofracking recession technical progress off shoring
Peak oil
Will we run out of fossil fuel INot soon enough to matter
0
200
400
600
800
Estimated Reserves
Emissions to Date
Gig
aton
s C
arbo
n
Oil Gas Coal Land Use
EIA
IPCCEIA
IPCC
100
200
300
Em
itted
CO
2 (p
pm)
0
200
400
600
800
We have oceans of coal and lots of oil and these figures predateUS fracking
Peak oil
Will we run out of fossil fuel II
Conclusion
Conclusion I
Here is where we stand with our model
maxIM
u(c1 c2) (14)
st W = c1 + I + M (15)
c2 = (1 + r)I minus γ(T2 minus T1)I (16)
E = (1 minus ρ4MW
)(ρ5(c1 + I)) (17)
P2 = ρ0E + P1 (18)
T2 = ρ1(P2 minus P1) + T1 (19)
We have enough pieces filled in to permit you to calculate theimpact on future climate of particular sorts of current consumptioneg burning a tank of propane on your bbq Wersquoll next start
Conclusion
Conclusion II
thinking about the effect of climate change on production γthough wersquoll make an aside to talk about measurement error first
Conclusion
Conclusion III
Each ppm of atmospheric CO2 corresponds to about 212 Gt C
and 778 Gt of CO2 Pay attention to the units people use
Not all gases are equal in their green house potential CO2 ismost common and most important but other gases are moreimportant per unit of emissions
Over the past 50 years about 55 of each emitted Gt of C
has stayed in the atmosphere The rest has been absorbed byland or oceans Thus it takes about 38 Gt C per 1ppm ofatmospheric CO2
Conclusion
Conclusion IV
Emissions are about 13Gt C for 2013 The rate at whichatmospheric CO2 is increasing has risen from about 1ppmyr1960s to 2ppm for 2000rsquos Since there is lots of fuel weshould expect atmospheric CO2 to continue to increase and atan increasing rate lsquobusiness as usual scenarios call foratmospheric CO2e gt 800 within 100 years
Not all countries are the same They are responsible fordifferent shares have different per capita emissions useemission more or less efficiently and are responsible fordifferent shares of historical emissions These factors are veryimportant obstacles to international agreements and alsosuggest the need for a richer model
Conclusion
Conclusion V
Steady state CO2 emissions are probably very small Sternsuggests less than 13 of current Our calculations suggest(1-055)=45
Atmospheric carbon cycle
Atmospheric CO2 cycle data III
So concentration yield of emissions is about 55 Thus
(1055)= 18 Gt C emissions gives 1 Gt ton of atmospheric C
212 Gt atmospheric C to gives 1ppm atmospheric C (or CO2 )
Multiplying 18 times 212 = 38Gt C of emissions to get 1ppm ofatmospheric concentration
Recall the carbon cycle equation from our model
P2 = ρ0E + P1
We have just calculated that ρ0 = 138 = 026ppm C (or CO2 )
Gt C
What is ρ0 if we denominate emissions in terms of CO2
Atmospheric carbon cycle
Atmospheric CO2 cycle data IV
In Hansenrsquos graph the fraction of emissions retained in theatmosphere is CONSTANT as emissions are increasing This isthought to reflect increased absorbtion by plant lsquocarbonfertilizationrsquo or increased lsquonet primary productivityrsquo
In AOGCMrsquos the carbon cycle is modelled very carefully We reallywant to deal with the possibility that absorbtion varies withtemperature or CO2 (it probably does) and there is a lot ofuncertainty about this relationship
Consumption and emissions
Emissions for particular activities I
CO2 from gasoline 23 kgliter = 194 poundsgallon So1000 kg of CO2 emission results from 435 liters or 114gallons of gas (about 1 not burned is mostly N2O so CO2e ishigher)
CO2 from diesel 27 kgliter = 222 poundsgallon 1000 kg ofCO2 emission results from 370 liters or 97 gallons of dieselhttpwwwepagovotaqclimate420f05001htmcalculating
BBQ propane tank about 18 pounds propane = 24kg = 53 lbCO2 (NB Gasoline weighs 63 poundsgallon so 18 poundsof gas gives about 54 pounds CO2 Propane has morehydrogen per carbon atom than gasoline)
Consumption and emissions
Emissions for particular activities II
CO2 sequestration by 1 acre 90 year old pine forest inSoutheastern US is about 100 tons C about 1 tonacreyearSo burning this acre releases about 100 tons C or 367 tonsCO2 httpwwwepagovsequestrationfaqhtml For tropical forests about 18times as much not reliable source
CO2 from coal about 200 tons CO2 per ton (a lot of the stuffin coal is not burned ndash I think) or 2100lb CO2 per 1000 KWHfrom non-baseload coal burning electricity generation CO2eis higher Baseload will usually be lower (often nuclear orhydro) httpwwweiagovtoolsfaqsfaqcfmid=74ampt=11
Consumption and emissions
Emissions for particular activities III
For natural gas about 1200lb CO2 per 1000 KWH Sofracking is fantastic unless too much methane leaks beforeitrsquos burnt With 1 ton of methane worth 23 tons of CO2 about43 leakage makes coal and natural gas even (unless thereis methane leakage from coal mines) The rate of leakage iscurrently contested EPA current estimate is about 06 but05 is probably better (Allen et al PNAS 2013)
For reference Avg household in RI = 500KWHmo Avghousehold in TX = 1000KWHmohttpswwweiagovtoolsfaqsfaqcfmid=97ampt=3 (Feb 2016) Or averagehousehold in Providence sim 8000kwhyear in 2001 Dallas sim18500kwhyear (Glaeser and Kahn JUE 2010)
Consumption and emissions
Emissions for particular activities IV
For thinking about fracking also consider the following
Consumption and emissions
Global emissions per unit of consumption ca 2013
Using these sorts of particular numbers together with informationabout aggregate consumption one can calculate world emissions
Global annual emissions ca 2013 are about 49Gt CO2e or49 times 12
44 sim 133 Gt C (more on this later)
World GDP in 2013 is about 77 trillion USD (NB this is W inour model)
Dividingwe have 133times109 tons C77times1012000USD = 133
7700ton CUSD sim 017 kg C
USD (1 ton= 1000 kg) Multiply by 4412 for CO2 instead of C
Recall the third equation from our global warming model
E = (1 minus ρ4MW
)(ρ5(c1 + I)) (7)
Wersquove just calculated ρ5 Why is this sloppy
Consumption and emissions
Emissions per unit of consumption by countryItrsquos also interesting to look at the country by countrybreakdown(ca 2004) The US and Canada make a lot of stuffper ton of emissions
IPCC 2007 Mitigation fig SPM3b
What if China and Africa made same output at USCAemission rates This is why technology transfer is importantCompare 068 kg CO2e per dollar ca 2004 to my calculationof 017 kg C per dollar 2013 How important is technicalprogress
Consumption and emissions
Technological progress I
httpwww3epagovclimatechangescienceindicatorsghgus-ghg-emissionshtml January 2016
Consumption and emissions
Technological progress II
Nordhaus does this calculation every year country by country
Russia
India
World
EU
US
China
Consumption and emissions
Emissions - Summary
Wersquove now calculated ρ5 emissions per GDP at about 017kgC per dollar ca 2013Looking at the data a little more carefully highlights twodeficiencies on our model
Technological progress is at work so this ratio changes overtimeThere are huge difference across places in this ratio
This highlights the importance of technological progress andtechnology transfer in solving the problem of climate change
Wersquoll address this when we get to the Nordhaus model
Emissions
Emissions trends and levels
Recall
maxIM
u(c1 c2) (8)
st W = c1 + I + M (9)
c2 = (1 + r)I minus γ(T2 minus T1)I (10)
E = (1 minus ρ4MW
)(ρ5(c1 + I)) (11)
P2 = ρ0E + P1 (12)
T2 = ρ1(P2 minus P1) + T1 (13)
Wersquove filled in a bit more The next step is to look at E This meanslooking at trends and levels in CO2 emissions
Emissions
CO2e 1970-2010
IPCC 2013 WG3 fig TS1
Right panel gives confidence bounds for 2010 49Gt CO2e in 2010
Emissions
CO2 by purpose and country income 1750-2010
IPCC 2013 WG3 fig TS2
Emissions
Hansenrsquos version of the same thing
Flow StockHansen 2009 fig 27
Contributions to stock and flow are very different At thenegotiating table developing countries want the right to emit sinceeveryone else had their turn
Emissions
2010 CO2e by purpose
IPCC 2013 WG3 fig TS3
Emissions
2010 CO2e by purpose and country income
IPCC 2013 WG3 fig TS3
Emissions
US 1990-2017 CO2e
ES-4 Inventory of US Greenhouse Gas Emissions and Sinks 1990ndash2017
ES2 Recent Trends in US Greenhouse Gas Emissions and Sinks
In 2017 total gross US greenhouse gas emissions were 64567 MMT or million metric tons of carbon dioxide (CO2) Eq11 Total US emissions have increased by 13 percent from 1990 to 2017 and emissions decreased from 2016 to 2017 by 05 percent (355 MMT CO2 Eq) The decrease in total greenhouse gas emissions between 2016 and 2017 was driven in part by a decrease in CO2 emissions from fossil fuel combustion The decrease in CO2 emissions from fossil fuel combustion was a result of multiple factors including a continued shift from coal to natural gas and increased use of renewable energy in the electric power sector and milder weather that contributed to less overall electricity use
Relative to 1990 the baseline for this Inventory gross emissions in 2017 are higher by 13 percent down from a high of 157 percent above 1990 levels in 2007 Overall net emissions in 2017 were 130 percent below 2005 levels as shown in Table ES-2 Figure ES-1 through Figure ES-3 illustrate the overall trends in total US emissions by gas annual changes and absolute change since 1990 and Table ES-2 provides a detailed summary of gross US greenhouse gas emissions and sinks for 1990 through 2017 Note unless otherwise stated all tables and figures provide total gross emissions and exclude the greenhouse gas fluxes from the Land Use Land-Use Change and Forestry (LULUCF) sector (see Section ES3 Overview of Sector Emissions and Trends)
Figure ES-1 Gross US Greenhouse Gas Emissions by Gas (MMT CO2 Eq)
11 The gross emissions total presented in this report for the United States excludes emissions and removals from Land Use Land-Use Change and Forestry (LULUCF) The net emissions total presented in this report for the United States includes emissions and removals from LULUCF
httpswwwepagovsitesproductionfiles2019-04documentsus-ghg-inventory-2019-main-textpdf September 2019
This reflects fracking recession technical progress off-shoring ofmanufacturing Emissions are likely up since 2017
Emissions
Emissions per person
Itrsquos also interesting to look at the country by country breakdown interms of emissions per capita
IPCC 2007 Mitigation fig SPM3a
As of 2012 US had 454 tons C person and for India this numberwas 046 China was 18(httpcdiacornlgovtrendsemistop2011cap)
Emissions
The problem of stabilizing atmospheric CO2Emissions are about 13Gt C per year
The ocean and biosphere absorb about 45 of emissions (sofar)
This means the ocean and biosphere absorb 13 times 045 asymp 6GtC per year
As a rough guess this means that reducing emissions to 6GtC per year will stabilize atmospheric CO2 (but not climate)
This involves a 55 decrease For an average American thismeans this means reducing emissions from 45 tons per yearto about 20 if US share of total emissions stays constant Ifemissions are allocated equally to each of the worldrsquos 74bpeople then each of us gets 6Gt C 74b people or about 08ton This is an 82 decrease for the average American It isalso about the twice the level of the average Indian and halfthat of the average Chinese
Emissions
Summary
2013 emissions of CO2e were about 49Gt Of this 35Gt wasCO2 and of this about 30Gt from fossil fuels and 5Gt fromland use change and agriculture This is E in our model
Emission are growing rapidly about 2year between 2000and 2010 1970 CO2e was 30Gt
2010 CO2e 14 transport 18 buildings 21 industry 24AFOLU We could use this to calculate refinements of ρ5
The countries responsible for most of the stock are not thecountries responsible for most of the flow
Per capita emissions vary by a factor of about 10 between richand poor countries
There has been a decline in US emissions since 2008 due tofracking recession technical progress off shoring
Peak oil
Will we run out of fossil fuel INot soon enough to matter
0
200
400
600
800
Estimated Reserves
Emissions to Date
Gig
aton
s C
arbo
n
Oil Gas Coal Land Use
EIA
IPCCEIA
IPCC
100
200
300
Em
itted
CO
2 (p
pm)
0
200
400
600
800
We have oceans of coal and lots of oil and these figures predateUS fracking
Peak oil
Will we run out of fossil fuel II
Conclusion
Conclusion I
Here is where we stand with our model
maxIM
u(c1 c2) (14)
st W = c1 + I + M (15)
c2 = (1 + r)I minus γ(T2 minus T1)I (16)
E = (1 minus ρ4MW
)(ρ5(c1 + I)) (17)
P2 = ρ0E + P1 (18)
T2 = ρ1(P2 minus P1) + T1 (19)
We have enough pieces filled in to permit you to calculate theimpact on future climate of particular sorts of current consumptioneg burning a tank of propane on your bbq Wersquoll next start
Conclusion
Conclusion II
thinking about the effect of climate change on production γthough wersquoll make an aside to talk about measurement error first
Conclusion
Conclusion III
Each ppm of atmospheric CO2 corresponds to about 212 Gt C
and 778 Gt of CO2 Pay attention to the units people use
Not all gases are equal in their green house potential CO2 ismost common and most important but other gases are moreimportant per unit of emissions
Over the past 50 years about 55 of each emitted Gt of C
has stayed in the atmosphere The rest has been absorbed byland or oceans Thus it takes about 38 Gt C per 1ppm ofatmospheric CO2
Conclusion
Conclusion IV
Emissions are about 13Gt C for 2013 The rate at whichatmospheric CO2 is increasing has risen from about 1ppmyr1960s to 2ppm for 2000rsquos Since there is lots of fuel weshould expect atmospheric CO2 to continue to increase and atan increasing rate lsquobusiness as usual scenarios call foratmospheric CO2e gt 800 within 100 years
Not all countries are the same They are responsible fordifferent shares have different per capita emissions useemission more or less efficiently and are responsible fordifferent shares of historical emissions These factors are veryimportant obstacles to international agreements and alsosuggest the need for a richer model
Conclusion
Conclusion V
Steady state CO2 emissions are probably very small Sternsuggests less than 13 of current Our calculations suggest(1-055)=45
Atmospheric carbon cycle
Atmospheric CO2 cycle data IV
In Hansenrsquos graph the fraction of emissions retained in theatmosphere is CONSTANT as emissions are increasing This isthought to reflect increased absorbtion by plant lsquocarbonfertilizationrsquo or increased lsquonet primary productivityrsquo
In AOGCMrsquos the carbon cycle is modelled very carefully We reallywant to deal with the possibility that absorbtion varies withtemperature or CO2 (it probably does) and there is a lot ofuncertainty about this relationship
Consumption and emissions
Emissions for particular activities I
CO2 from gasoline 23 kgliter = 194 poundsgallon So1000 kg of CO2 emission results from 435 liters or 114gallons of gas (about 1 not burned is mostly N2O so CO2e ishigher)
CO2 from diesel 27 kgliter = 222 poundsgallon 1000 kg ofCO2 emission results from 370 liters or 97 gallons of dieselhttpwwwepagovotaqclimate420f05001htmcalculating
BBQ propane tank about 18 pounds propane = 24kg = 53 lbCO2 (NB Gasoline weighs 63 poundsgallon so 18 poundsof gas gives about 54 pounds CO2 Propane has morehydrogen per carbon atom than gasoline)
Consumption and emissions
Emissions for particular activities II
CO2 sequestration by 1 acre 90 year old pine forest inSoutheastern US is about 100 tons C about 1 tonacreyearSo burning this acre releases about 100 tons C or 367 tonsCO2 httpwwwepagovsequestrationfaqhtml For tropical forests about 18times as much not reliable source
CO2 from coal about 200 tons CO2 per ton (a lot of the stuffin coal is not burned ndash I think) or 2100lb CO2 per 1000 KWHfrom non-baseload coal burning electricity generation CO2eis higher Baseload will usually be lower (often nuclear orhydro) httpwwweiagovtoolsfaqsfaqcfmid=74ampt=11
Consumption and emissions
Emissions for particular activities III
For natural gas about 1200lb CO2 per 1000 KWH Sofracking is fantastic unless too much methane leaks beforeitrsquos burnt With 1 ton of methane worth 23 tons of CO2 about43 leakage makes coal and natural gas even (unless thereis methane leakage from coal mines) The rate of leakage iscurrently contested EPA current estimate is about 06 but05 is probably better (Allen et al PNAS 2013)
For reference Avg household in RI = 500KWHmo Avghousehold in TX = 1000KWHmohttpswwweiagovtoolsfaqsfaqcfmid=97ampt=3 (Feb 2016) Or averagehousehold in Providence sim 8000kwhyear in 2001 Dallas sim18500kwhyear (Glaeser and Kahn JUE 2010)
Consumption and emissions
Emissions for particular activities IV
For thinking about fracking also consider the following
Consumption and emissions
Global emissions per unit of consumption ca 2013
Using these sorts of particular numbers together with informationabout aggregate consumption one can calculate world emissions
Global annual emissions ca 2013 are about 49Gt CO2e or49 times 12
44 sim 133 Gt C (more on this later)
World GDP in 2013 is about 77 trillion USD (NB this is W inour model)
Dividingwe have 133times109 tons C77times1012000USD = 133
7700ton CUSD sim 017 kg C
USD (1 ton= 1000 kg) Multiply by 4412 for CO2 instead of C
Recall the third equation from our global warming model
E = (1 minus ρ4MW
)(ρ5(c1 + I)) (7)
Wersquove just calculated ρ5 Why is this sloppy
Consumption and emissions
Emissions per unit of consumption by countryItrsquos also interesting to look at the country by countrybreakdown(ca 2004) The US and Canada make a lot of stuffper ton of emissions
IPCC 2007 Mitigation fig SPM3b
What if China and Africa made same output at USCAemission rates This is why technology transfer is importantCompare 068 kg CO2e per dollar ca 2004 to my calculationof 017 kg C per dollar 2013 How important is technicalprogress
Consumption and emissions
Technological progress I
httpwww3epagovclimatechangescienceindicatorsghgus-ghg-emissionshtml January 2016
Consumption and emissions
Technological progress II
Nordhaus does this calculation every year country by country
Russia
India
World
EU
US
China
Consumption and emissions
Emissions - Summary
Wersquove now calculated ρ5 emissions per GDP at about 017kgC per dollar ca 2013Looking at the data a little more carefully highlights twodeficiencies on our model
Technological progress is at work so this ratio changes overtimeThere are huge difference across places in this ratio
This highlights the importance of technological progress andtechnology transfer in solving the problem of climate change
Wersquoll address this when we get to the Nordhaus model
Emissions
Emissions trends and levels
Recall
maxIM
u(c1 c2) (8)
st W = c1 + I + M (9)
c2 = (1 + r)I minus γ(T2 minus T1)I (10)
E = (1 minus ρ4MW
)(ρ5(c1 + I)) (11)
P2 = ρ0E + P1 (12)
T2 = ρ1(P2 minus P1) + T1 (13)
Wersquove filled in a bit more The next step is to look at E This meanslooking at trends and levels in CO2 emissions
Emissions
CO2e 1970-2010
IPCC 2013 WG3 fig TS1
Right panel gives confidence bounds for 2010 49Gt CO2e in 2010
Emissions
CO2 by purpose and country income 1750-2010
IPCC 2013 WG3 fig TS2
Emissions
Hansenrsquos version of the same thing
Flow StockHansen 2009 fig 27
Contributions to stock and flow are very different At thenegotiating table developing countries want the right to emit sinceeveryone else had their turn
Emissions
2010 CO2e by purpose
IPCC 2013 WG3 fig TS3
Emissions
2010 CO2e by purpose and country income
IPCC 2013 WG3 fig TS3
Emissions
US 1990-2017 CO2e
ES-4 Inventory of US Greenhouse Gas Emissions and Sinks 1990ndash2017
ES2 Recent Trends in US Greenhouse Gas Emissions and Sinks
In 2017 total gross US greenhouse gas emissions were 64567 MMT or million metric tons of carbon dioxide (CO2) Eq11 Total US emissions have increased by 13 percent from 1990 to 2017 and emissions decreased from 2016 to 2017 by 05 percent (355 MMT CO2 Eq) The decrease in total greenhouse gas emissions between 2016 and 2017 was driven in part by a decrease in CO2 emissions from fossil fuel combustion The decrease in CO2 emissions from fossil fuel combustion was a result of multiple factors including a continued shift from coal to natural gas and increased use of renewable energy in the electric power sector and milder weather that contributed to less overall electricity use
Relative to 1990 the baseline for this Inventory gross emissions in 2017 are higher by 13 percent down from a high of 157 percent above 1990 levels in 2007 Overall net emissions in 2017 were 130 percent below 2005 levels as shown in Table ES-2 Figure ES-1 through Figure ES-3 illustrate the overall trends in total US emissions by gas annual changes and absolute change since 1990 and Table ES-2 provides a detailed summary of gross US greenhouse gas emissions and sinks for 1990 through 2017 Note unless otherwise stated all tables and figures provide total gross emissions and exclude the greenhouse gas fluxes from the Land Use Land-Use Change and Forestry (LULUCF) sector (see Section ES3 Overview of Sector Emissions and Trends)
Figure ES-1 Gross US Greenhouse Gas Emissions by Gas (MMT CO2 Eq)
11 The gross emissions total presented in this report for the United States excludes emissions and removals from Land Use Land-Use Change and Forestry (LULUCF) The net emissions total presented in this report for the United States includes emissions and removals from LULUCF
httpswwwepagovsitesproductionfiles2019-04documentsus-ghg-inventory-2019-main-textpdf September 2019
This reflects fracking recession technical progress off-shoring ofmanufacturing Emissions are likely up since 2017
Emissions
Emissions per person
Itrsquos also interesting to look at the country by country breakdown interms of emissions per capita
IPCC 2007 Mitigation fig SPM3a
As of 2012 US had 454 tons C person and for India this numberwas 046 China was 18(httpcdiacornlgovtrendsemistop2011cap)
Emissions
The problem of stabilizing atmospheric CO2Emissions are about 13Gt C per year
The ocean and biosphere absorb about 45 of emissions (sofar)
This means the ocean and biosphere absorb 13 times 045 asymp 6GtC per year
As a rough guess this means that reducing emissions to 6GtC per year will stabilize atmospheric CO2 (but not climate)
This involves a 55 decrease For an average American thismeans this means reducing emissions from 45 tons per yearto about 20 if US share of total emissions stays constant Ifemissions are allocated equally to each of the worldrsquos 74bpeople then each of us gets 6Gt C 74b people or about 08ton This is an 82 decrease for the average American It isalso about the twice the level of the average Indian and halfthat of the average Chinese
Emissions
Summary
2013 emissions of CO2e were about 49Gt Of this 35Gt wasCO2 and of this about 30Gt from fossil fuels and 5Gt fromland use change and agriculture This is E in our model
Emission are growing rapidly about 2year between 2000and 2010 1970 CO2e was 30Gt
2010 CO2e 14 transport 18 buildings 21 industry 24AFOLU We could use this to calculate refinements of ρ5
The countries responsible for most of the stock are not thecountries responsible for most of the flow
Per capita emissions vary by a factor of about 10 between richand poor countries
There has been a decline in US emissions since 2008 due tofracking recession technical progress off shoring
Peak oil
Will we run out of fossil fuel INot soon enough to matter
0
200
400
600
800
Estimated Reserves
Emissions to Date
Gig
aton
s C
arbo
n
Oil Gas Coal Land Use
EIA
IPCCEIA
IPCC
100
200
300
Em
itted
CO
2 (p
pm)
0
200
400
600
800
We have oceans of coal and lots of oil and these figures predateUS fracking
Peak oil
Will we run out of fossil fuel II
Conclusion
Conclusion I
Here is where we stand with our model
maxIM
u(c1 c2) (14)
st W = c1 + I + M (15)
c2 = (1 + r)I minus γ(T2 minus T1)I (16)
E = (1 minus ρ4MW
)(ρ5(c1 + I)) (17)
P2 = ρ0E + P1 (18)
T2 = ρ1(P2 minus P1) + T1 (19)
We have enough pieces filled in to permit you to calculate theimpact on future climate of particular sorts of current consumptioneg burning a tank of propane on your bbq Wersquoll next start
Conclusion
Conclusion II
thinking about the effect of climate change on production γthough wersquoll make an aside to talk about measurement error first
Conclusion
Conclusion III
Each ppm of atmospheric CO2 corresponds to about 212 Gt C
and 778 Gt of CO2 Pay attention to the units people use
Not all gases are equal in their green house potential CO2 ismost common and most important but other gases are moreimportant per unit of emissions
Over the past 50 years about 55 of each emitted Gt of C
has stayed in the atmosphere The rest has been absorbed byland or oceans Thus it takes about 38 Gt C per 1ppm ofatmospheric CO2
Conclusion
Conclusion IV
Emissions are about 13Gt C for 2013 The rate at whichatmospheric CO2 is increasing has risen from about 1ppmyr1960s to 2ppm for 2000rsquos Since there is lots of fuel weshould expect atmospheric CO2 to continue to increase and atan increasing rate lsquobusiness as usual scenarios call foratmospheric CO2e gt 800 within 100 years
Not all countries are the same They are responsible fordifferent shares have different per capita emissions useemission more or less efficiently and are responsible fordifferent shares of historical emissions These factors are veryimportant obstacles to international agreements and alsosuggest the need for a richer model
Conclusion
Conclusion V
Steady state CO2 emissions are probably very small Sternsuggests less than 13 of current Our calculations suggest(1-055)=45
Consumption and emissions
Emissions for particular activities I
CO2 from gasoline 23 kgliter = 194 poundsgallon So1000 kg of CO2 emission results from 435 liters or 114gallons of gas (about 1 not burned is mostly N2O so CO2e ishigher)
CO2 from diesel 27 kgliter = 222 poundsgallon 1000 kg ofCO2 emission results from 370 liters or 97 gallons of dieselhttpwwwepagovotaqclimate420f05001htmcalculating
BBQ propane tank about 18 pounds propane = 24kg = 53 lbCO2 (NB Gasoline weighs 63 poundsgallon so 18 poundsof gas gives about 54 pounds CO2 Propane has morehydrogen per carbon atom than gasoline)
Consumption and emissions
Emissions for particular activities II
CO2 sequestration by 1 acre 90 year old pine forest inSoutheastern US is about 100 tons C about 1 tonacreyearSo burning this acre releases about 100 tons C or 367 tonsCO2 httpwwwepagovsequestrationfaqhtml For tropical forests about 18times as much not reliable source
CO2 from coal about 200 tons CO2 per ton (a lot of the stuffin coal is not burned ndash I think) or 2100lb CO2 per 1000 KWHfrom non-baseload coal burning electricity generation CO2eis higher Baseload will usually be lower (often nuclear orhydro) httpwwweiagovtoolsfaqsfaqcfmid=74ampt=11
Consumption and emissions
Emissions for particular activities III
For natural gas about 1200lb CO2 per 1000 KWH Sofracking is fantastic unless too much methane leaks beforeitrsquos burnt With 1 ton of methane worth 23 tons of CO2 about43 leakage makes coal and natural gas even (unless thereis methane leakage from coal mines) The rate of leakage iscurrently contested EPA current estimate is about 06 but05 is probably better (Allen et al PNAS 2013)
For reference Avg household in RI = 500KWHmo Avghousehold in TX = 1000KWHmohttpswwweiagovtoolsfaqsfaqcfmid=97ampt=3 (Feb 2016) Or averagehousehold in Providence sim 8000kwhyear in 2001 Dallas sim18500kwhyear (Glaeser and Kahn JUE 2010)
Consumption and emissions
Emissions for particular activities IV
For thinking about fracking also consider the following
Consumption and emissions
Global emissions per unit of consumption ca 2013
Using these sorts of particular numbers together with informationabout aggregate consumption one can calculate world emissions
Global annual emissions ca 2013 are about 49Gt CO2e or49 times 12
44 sim 133 Gt C (more on this later)
World GDP in 2013 is about 77 trillion USD (NB this is W inour model)
Dividingwe have 133times109 tons C77times1012000USD = 133
7700ton CUSD sim 017 kg C
USD (1 ton= 1000 kg) Multiply by 4412 for CO2 instead of C
Recall the third equation from our global warming model
E = (1 minus ρ4MW
)(ρ5(c1 + I)) (7)
Wersquove just calculated ρ5 Why is this sloppy
Consumption and emissions
Emissions per unit of consumption by countryItrsquos also interesting to look at the country by countrybreakdown(ca 2004) The US and Canada make a lot of stuffper ton of emissions
IPCC 2007 Mitigation fig SPM3b
What if China and Africa made same output at USCAemission rates This is why technology transfer is importantCompare 068 kg CO2e per dollar ca 2004 to my calculationof 017 kg C per dollar 2013 How important is technicalprogress
Consumption and emissions
Technological progress I
httpwww3epagovclimatechangescienceindicatorsghgus-ghg-emissionshtml January 2016
Consumption and emissions
Technological progress II
Nordhaus does this calculation every year country by country
Russia
India
World
EU
US
China
Consumption and emissions
Emissions - Summary
Wersquove now calculated ρ5 emissions per GDP at about 017kgC per dollar ca 2013Looking at the data a little more carefully highlights twodeficiencies on our model
Technological progress is at work so this ratio changes overtimeThere are huge difference across places in this ratio
This highlights the importance of technological progress andtechnology transfer in solving the problem of climate change
Wersquoll address this when we get to the Nordhaus model
Emissions
Emissions trends and levels
Recall
maxIM
u(c1 c2) (8)
st W = c1 + I + M (9)
c2 = (1 + r)I minus γ(T2 minus T1)I (10)
E = (1 minus ρ4MW
)(ρ5(c1 + I)) (11)
P2 = ρ0E + P1 (12)
T2 = ρ1(P2 minus P1) + T1 (13)
Wersquove filled in a bit more The next step is to look at E This meanslooking at trends and levels in CO2 emissions
Emissions
CO2e 1970-2010
IPCC 2013 WG3 fig TS1
Right panel gives confidence bounds for 2010 49Gt CO2e in 2010
Emissions
CO2 by purpose and country income 1750-2010
IPCC 2013 WG3 fig TS2
Emissions
Hansenrsquos version of the same thing
Flow StockHansen 2009 fig 27
Contributions to stock and flow are very different At thenegotiating table developing countries want the right to emit sinceeveryone else had their turn
Emissions
2010 CO2e by purpose
IPCC 2013 WG3 fig TS3
Emissions
2010 CO2e by purpose and country income
IPCC 2013 WG3 fig TS3
Emissions
US 1990-2017 CO2e
ES-4 Inventory of US Greenhouse Gas Emissions and Sinks 1990ndash2017
ES2 Recent Trends in US Greenhouse Gas Emissions and Sinks
In 2017 total gross US greenhouse gas emissions were 64567 MMT or million metric tons of carbon dioxide (CO2) Eq11 Total US emissions have increased by 13 percent from 1990 to 2017 and emissions decreased from 2016 to 2017 by 05 percent (355 MMT CO2 Eq) The decrease in total greenhouse gas emissions between 2016 and 2017 was driven in part by a decrease in CO2 emissions from fossil fuel combustion The decrease in CO2 emissions from fossil fuel combustion was a result of multiple factors including a continued shift from coal to natural gas and increased use of renewable energy in the electric power sector and milder weather that contributed to less overall electricity use
Relative to 1990 the baseline for this Inventory gross emissions in 2017 are higher by 13 percent down from a high of 157 percent above 1990 levels in 2007 Overall net emissions in 2017 were 130 percent below 2005 levels as shown in Table ES-2 Figure ES-1 through Figure ES-3 illustrate the overall trends in total US emissions by gas annual changes and absolute change since 1990 and Table ES-2 provides a detailed summary of gross US greenhouse gas emissions and sinks for 1990 through 2017 Note unless otherwise stated all tables and figures provide total gross emissions and exclude the greenhouse gas fluxes from the Land Use Land-Use Change and Forestry (LULUCF) sector (see Section ES3 Overview of Sector Emissions and Trends)
Figure ES-1 Gross US Greenhouse Gas Emissions by Gas (MMT CO2 Eq)
11 The gross emissions total presented in this report for the United States excludes emissions and removals from Land Use Land-Use Change and Forestry (LULUCF) The net emissions total presented in this report for the United States includes emissions and removals from LULUCF
httpswwwepagovsitesproductionfiles2019-04documentsus-ghg-inventory-2019-main-textpdf September 2019
This reflects fracking recession technical progress off-shoring ofmanufacturing Emissions are likely up since 2017
Emissions
Emissions per person
Itrsquos also interesting to look at the country by country breakdown interms of emissions per capita
IPCC 2007 Mitigation fig SPM3a
As of 2012 US had 454 tons C person and for India this numberwas 046 China was 18(httpcdiacornlgovtrendsemistop2011cap)
Emissions
The problem of stabilizing atmospheric CO2Emissions are about 13Gt C per year
The ocean and biosphere absorb about 45 of emissions (sofar)
This means the ocean and biosphere absorb 13 times 045 asymp 6GtC per year
As a rough guess this means that reducing emissions to 6GtC per year will stabilize atmospheric CO2 (but not climate)
This involves a 55 decrease For an average American thismeans this means reducing emissions from 45 tons per yearto about 20 if US share of total emissions stays constant Ifemissions are allocated equally to each of the worldrsquos 74bpeople then each of us gets 6Gt C 74b people or about 08ton This is an 82 decrease for the average American It isalso about the twice the level of the average Indian and halfthat of the average Chinese
Emissions
Summary
2013 emissions of CO2e were about 49Gt Of this 35Gt wasCO2 and of this about 30Gt from fossil fuels and 5Gt fromland use change and agriculture This is E in our model
Emission are growing rapidly about 2year between 2000and 2010 1970 CO2e was 30Gt
2010 CO2e 14 transport 18 buildings 21 industry 24AFOLU We could use this to calculate refinements of ρ5
The countries responsible for most of the stock are not thecountries responsible for most of the flow
Per capita emissions vary by a factor of about 10 between richand poor countries
There has been a decline in US emissions since 2008 due tofracking recession technical progress off shoring
Peak oil
Will we run out of fossil fuel INot soon enough to matter
0
200
400
600
800
Estimated Reserves
Emissions to Date
Gig
aton
s C
arbo
n
Oil Gas Coal Land Use
EIA
IPCCEIA
IPCC
100
200
300
Em
itted
CO
2 (p
pm)
0
200
400
600
800
We have oceans of coal and lots of oil and these figures predateUS fracking
Peak oil
Will we run out of fossil fuel II
Conclusion
Conclusion I
Here is where we stand with our model
maxIM
u(c1 c2) (14)
st W = c1 + I + M (15)
c2 = (1 + r)I minus γ(T2 minus T1)I (16)
E = (1 minus ρ4MW
)(ρ5(c1 + I)) (17)
P2 = ρ0E + P1 (18)
T2 = ρ1(P2 minus P1) + T1 (19)
We have enough pieces filled in to permit you to calculate theimpact on future climate of particular sorts of current consumptioneg burning a tank of propane on your bbq Wersquoll next start
Conclusion
Conclusion II
thinking about the effect of climate change on production γthough wersquoll make an aside to talk about measurement error first
Conclusion
Conclusion III
Each ppm of atmospheric CO2 corresponds to about 212 Gt C
and 778 Gt of CO2 Pay attention to the units people use
Not all gases are equal in their green house potential CO2 ismost common and most important but other gases are moreimportant per unit of emissions
Over the past 50 years about 55 of each emitted Gt of C
has stayed in the atmosphere The rest has been absorbed byland or oceans Thus it takes about 38 Gt C per 1ppm ofatmospheric CO2
Conclusion
Conclusion IV
Emissions are about 13Gt C for 2013 The rate at whichatmospheric CO2 is increasing has risen from about 1ppmyr1960s to 2ppm for 2000rsquos Since there is lots of fuel weshould expect atmospheric CO2 to continue to increase and atan increasing rate lsquobusiness as usual scenarios call foratmospheric CO2e gt 800 within 100 years
Not all countries are the same They are responsible fordifferent shares have different per capita emissions useemission more or less efficiently and are responsible fordifferent shares of historical emissions These factors are veryimportant obstacles to international agreements and alsosuggest the need for a richer model
Conclusion
Conclusion V
Steady state CO2 emissions are probably very small Sternsuggests less than 13 of current Our calculations suggest(1-055)=45
Consumption and emissions
Emissions for particular activities II
CO2 sequestration by 1 acre 90 year old pine forest inSoutheastern US is about 100 tons C about 1 tonacreyearSo burning this acre releases about 100 tons C or 367 tonsCO2 httpwwwepagovsequestrationfaqhtml For tropical forests about 18times as much not reliable source
CO2 from coal about 200 tons CO2 per ton (a lot of the stuffin coal is not burned ndash I think) or 2100lb CO2 per 1000 KWHfrom non-baseload coal burning electricity generation CO2eis higher Baseload will usually be lower (often nuclear orhydro) httpwwweiagovtoolsfaqsfaqcfmid=74ampt=11
Consumption and emissions
Emissions for particular activities III
For natural gas about 1200lb CO2 per 1000 KWH Sofracking is fantastic unless too much methane leaks beforeitrsquos burnt With 1 ton of methane worth 23 tons of CO2 about43 leakage makes coal and natural gas even (unless thereis methane leakage from coal mines) The rate of leakage iscurrently contested EPA current estimate is about 06 but05 is probably better (Allen et al PNAS 2013)
For reference Avg household in RI = 500KWHmo Avghousehold in TX = 1000KWHmohttpswwweiagovtoolsfaqsfaqcfmid=97ampt=3 (Feb 2016) Or averagehousehold in Providence sim 8000kwhyear in 2001 Dallas sim18500kwhyear (Glaeser and Kahn JUE 2010)
Consumption and emissions
Emissions for particular activities IV
For thinking about fracking also consider the following
Consumption and emissions
Global emissions per unit of consumption ca 2013
Using these sorts of particular numbers together with informationabout aggregate consumption one can calculate world emissions
Global annual emissions ca 2013 are about 49Gt CO2e or49 times 12
44 sim 133 Gt C (more on this later)
World GDP in 2013 is about 77 trillion USD (NB this is W inour model)
Dividingwe have 133times109 tons C77times1012000USD = 133
7700ton CUSD sim 017 kg C
USD (1 ton= 1000 kg) Multiply by 4412 for CO2 instead of C
Recall the third equation from our global warming model
E = (1 minus ρ4MW
)(ρ5(c1 + I)) (7)
Wersquove just calculated ρ5 Why is this sloppy
Consumption and emissions
Emissions per unit of consumption by countryItrsquos also interesting to look at the country by countrybreakdown(ca 2004) The US and Canada make a lot of stuffper ton of emissions
IPCC 2007 Mitigation fig SPM3b
What if China and Africa made same output at USCAemission rates This is why technology transfer is importantCompare 068 kg CO2e per dollar ca 2004 to my calculationof 017 kg C per dollar 2013 How important is technicalprogress
Consumption and emissions
Technological progress I
httpwww3epagovclimatechangescienceindicatorsghgus-ghg-emissionshtml January 2016
Consumption and emissions
Technological progress II
Nordhaus does this calculation every year country by country
Russia
India
World
EU
US
China
Consumption and emissions
Emissions - Summary
Wersquove now calculated ρ5 emissions per GDP at about 017kgC per dollar ca 2013Looking at the data a little more carefully highlights twodeficiencies on our model
Technological progress is at work so this ratio changes overtimeThere are huge difference across places in this ratio
This highlights the importance of technological progress andtechnology transfer in solving the problem of climate change
Wersquoll address this when we get to the Nordhaus model
Emissions
Emissions trends and levels
Recall
maxIM
u(c1 c2) (8)
st W = c1 + I + M (9)
c2 = (1 + r)I minus γ(T2 minus T1)I (10)
E = (1 minus ρ4MW
)(ρ5(c1 + I)) (11)
P2 = ρ0E + P1 (12)
T2 = ρ1(P2 minus P1) + T1 (13)
Wersquove filled in a bit more The next step is to look at E This meanslooking at trends and levels in CO2 emissions
Emissions
CO2e 1970-2010
IPCC 2013 WG3 fig TS1
Right panel gives confidence bounds for 2010 49Gt CO2e in 2010
Emissions
CO2 by purpose and country income 1750-2010
IPCC 2013 WG3 fig TS2
Emissions
Hansenrsquos version of the same thing
Flow StockHansen 2009 fig 27
Contributions to stock and flow are very different At thenegotiating table developing countries want the right to emit sinceeveryone else had their turn
Emissions
2010 CO2e by purpose
IPCC 2013 WG3 fig TS3
Emissions
2010 CO2e by purpose and country income
IPCC 2013 WG3 fig TS3
Emissions
US 1990-2017 CO2e
ES-4 Inventory of US Greenhouse Gas Emissions and Sinks 1990ndash2017
ES2 Recent Trends in US Greenhouse Gas Emissions and Sinks
In 2017 total gross US greenhouse gas emissions were 64567 MMT or million metric tons of carbon dioxide (CO2) Eq11 Total US emissions have increased by 13 percent from 1990 to 2017 and emissions decreased from 2016 to 2017 by 05 percent (355 MMT CO2 Eq) The decrease in total greenhouse gas emissions between 2016 and 2017 was driven in part by a decrease in CO2 emissions from fossil fuel combustion The decrease in CO2 emissions from fossil fuel combustion was a result of multiple factors including a continued shift from coal to natural gas and increased use of renewable energy in the electric power sector and milder weather that contributed to less overall electricity use
Relative to 1990 the baseline for this Inventory gross emissions in 2017 are higher by 13 percent down from a high of 157 percent above 1990 levels in 2007 Overall net emissions in 2017 were 130 percent below 2005 levels as shown in Table ES-2 Figure ES-1 through Figure ES-3 illustrate the overall trends in total US emissions by gas annual changes and absolute change since 1990 and Table ES-2 provides a detailed summary of gross US greenhouse gas emissions and sinks for 1990 through 2017 Note unless otherwise stated all tables and figures provide total gross emissions and exclude the greenhouse gas fluxes from the Land Use Land-Use Change and Forestry (LULUCF) sector (see Section ES3 Overview of Sector Emissions and Trends)
Figure ES-1 Gross US Greenhouse Gas Emissions by Gas (MMT CO2 Eq)
11 The gross emissions total presented in this report for the United States excludes emissions and removals from Land Use Land-Use Change and Forestry (LULUCF) The net emissions total presented in this report for the United States includes emissions and removals from LULUCF
httpswwwepagovsitesproductionfiles2019-04documentsus-ghg-inventory-2019-main-textpdf September 2019
This reflects fracking recession technical progress off-shoring ofmanufacturing Emissions are likely up since 2017
Emissions
Emissions per person
Itrsquos also interesting to look at the country by country breakdown interms of emissions per capita
IPCC 2007 Mitigation fig SPM3a
As of 2012 US had 454 tons C person and for India this numberwas 046 China was 18(httpcdiacornlgovtrendsemistop2011cap)
Emissions
The problem of stabilizing atmospheric CO2Emissions are about 13Gt C per year
The ocean and biosphere absorb about 45 of emissions (sofar)
This means the ocean and biosphere absorb 13 times 045 asymp 6GtC per year
As a rough guess this means that reducing emissions to 6GtC per year will stabilize atmospheric CO2 (but not climate)
This involves a 55 decrease For an average American thismeans this means reducing emissions from 45 tons per yearto about 20 if US share of total emissions stays constant Ifemissions are allocated equally to each of the worldrsquos 74bpeople then each of us gets 6Gt C 74b people or about 08ton This is an 82 decrease for the average American It isalso about the twice the level of the average Indian and halfthat of the average Chinese
Emissions
Summary
2013 emissions of CO2e were about 49Gt Of this 35Gt wasCO2 and of this about 30Gt from fossil fuels and 5Gt fromland use change and agriculture This is E in our model
Emission are growing rapidly about 2year between 2000and 2010 1970 CO2e was 30Gt
2010 CO2e 14 transport 18 buildings 21 industry 24AFOLU We could use this to calculate refinements of ρ5
The countries responsible for most of the stock are not thecountries responsible for most of the flow
Per capita emissions vary by a factor of about 10 between richand poor countries
There has been a decline in US emissions since 2008 due tofracking recession technical progress off shoring
Peak oil
Will we run out of fossil fuel INot soon enough to matter
0
200
400
600
800
Estimated Reserves
Emissions to Date
Gig
aton
s C
arbo
n
Oil Gas Coal Land Use
EIA
IPCCEIA
IPCC
100
200
300
Em
itted
CO
2 (p
pm)
0
200
400
600
800
We have oceans of coal and lots of oil and these figures predateUS fracking
Peak oil
Will we run out of fossil fuel II
Conclusion
Conclusion I
Here is where we stand with our model
maxIM
u(c1 c2) (14)
st W = c1 + I + M (15)
c2 = (1 + r)I minus γ(T2 minus T1)I (16)
E = (1 minus ρ4MW
)(ρ5(c1 + I)) (17)
P2 = ρ0E + P1 (18)
T2 = ρ1(P2 minus P1) + T1 (19)
We have enough pieces filled in to permit you to calculate theimpact on future climate of particular sorts of current consumptioneg burning a tank of propane on your bbq Wersquoll next start
Conclusion
Conclusion II
thinking about the effect of climate change on production γthough wersquoll make an aside to talk about measurement error first
Conclusion
Conclusion III
Each ppm of atmospheric CO2 corresponds to about 212 Gt C
and 778 Gt of CO2 Pay attention to the units people use
Not all gases are equal in their green house potential CO2 ismost common and most important but other gases are moreimportant per unit of emissions
Over the past 50 years about 55 of each emitted Gt of C
has stayed in the atmosphere The rest has been absorbed byland or oceans Thus it takes about 38 Gt C per 1ppm ofatmospheric CO2
Conclusion
Conclusion IV
Emissions are about 13Gt C for 2013 The rate at whichatmospheric CO2 is increasing has risen from about 1ppmyr1960s to 2ppm for 2000rsquos Since there is lots of fuel weshould expect atmospheric CO2 to continue to increase and atan increasing rate lsquobusiness as usual scenarios call foratmospheric CO2e gt 800 within 100 years
Not all countries are the same They are responsible fordifferent shares have different per capita emissions useemission more or less efficiently and are responsible fordifferent shares of historical emissions These factors are veryimportant obstacles to international agreements and alsosuggest the need for a richer model
Conclusion
Conclusion V
Steady state CO2 emissions are probably very small Sternsuggests less than 13 of current Our calculations suggest(1-055)=45
Consumption and emissions
Emissions for particular activities III
For natural gas about 1200lb CO2 per 1000 KWH Sofracking is fantastic unless too much methane leaks beforeitrsquos burnt With 1 ton of methane worth 23 tons of CO2 about43 leakage makes coal and natural gas even (unless thereis methane leakage from coal mines) The rate of leakage iscurrently contested EPA current estimate is about 06 but05 is probably better (Allen et al PNAS 2013)
For reference Avg household in RI = 500KWHmo Avghousehold in TX = 1000KWHmohttpswwweiagovtoolsfaqsfaqcfmid=97ampt=3 (Feb 2016) Or averagehousehold in Providence sim 8000kwhyear in 2001 Dallas sim18500kwhyear (Glaeser and Kahn JUE 2010)
Consumption and emissions
Emissions for particular activities IV
For thinking about fracking also consider the following
Consumption and emissions
Global emissions per unit of consumption ca 2013
Using these sorts of particular numbers together with informationabout aggregate consumption one can calculate world emissions
Global annual emissions ca 2013 are about 49Gt CO2e or49 times 12
44 sim 133 Gt C (more on this later)
World GDP in 2013 is about 77 trillion USD (NB this is W inour model)
Dividingwe have 133times109 tons C77times1012000USD = 133
7700ton CUSD sim 017 kg C
USD (1 ton= 1000 kg) Multiply by 4412 for CO2 instead of C
Recall the third equation from our global warming model
E = (1 minus ρ4MW
)(ρ5(c1 + I)) (7)
Wersquove just calculated ρ5 Why is this sloppy
Consumption and emissions
Emissions per unit of consumption by countryItrsquos also interesting to look at the country by countrybreakdown(ca 2004) The US and Canada make a lot of stuffper ton of emissions
IPCC 2007 Mitigation fig SPM3b
What if China and Africa made same output at USCAemission rates This is why technology transfer is importantCompare 068 kg CO2e per dollar ca 2004 to my calculationof 017 kg C per dollar 2013 How important is technicalprogress
Consumption and emissions
Technological progress I
httpwww3epagovclimatechangescienceindicatorsghgus-ghg-emissionshtml January 2016
Consumption and emissions
Technological progress II
Nordhaus does this calculation every year country by country
Russia
India
World
EU
US
China
Consumption and emissions
Emissions - Summary
Wersquove now calculated ρ5 emissions per GDP at about 017kgC per dollar ca 2013Looking at the data a little more carefully highlights twodeficiencies on our model
Technological progress is at work so this ratio changes overtimeThere are huge difference across places in this ratio
This highlights the importance of technological progress andtechnology transfer in solving the problem of climate change
Wersquoll address this when we get to the Nordhaus model
Emissions
Emissions trends and levels
Recall
maxIM
u(c1 c2) (8)
st W = c1 + I + M (9)
c2 = (1 + r)I minus γ(T2 minus T1)I (10)
E = (1 minus ρ4MW
)(ρ5(c1 + I)) (11)
P2 = ρ0E + P1 (12)
T2 = ρ1(P2 minus P1) + T1 (13)
Wersquove filled in a bit more The next step is to look at E This meanslooking at trends and levels in CO2 emissions
Emissions
CO2e 1970-2010
IPCC 2013 WG3 fig TS1
Right panel gives confidence bounds for 2010 49Gt CO2e in 2010
Emissions
CO2 by purpose and country income 1750-2010
IPCC 2013 WG3 fig TS2
Emissions
Hansenrsquos version of the same thing
Flow StockHansen 2009 fig 27
Contributions to stock and flow are very different At thenegotiating table developing countries want the right to emit sinceeveryone else had their turn
Emissions
2010 CO2e by purpose
IPCC 2013 WG3 fig TS3
Emissions
2010 CO2e by purpose and country income
IPCC 2013 WG3 fig TS3
Emissions
US 1990-2017 CO2e
ES-4 Inventory of US Greenhouse Gas Emissions and Sinks 1990ndash2017
ES2 Recent Trends in US Greenhouse Gas Emissions and Sinks
In 2017 total gross US greenhouse gas emissions were 64567 MMT or million metric tons of carbon dioxide (CO2) Eq11 Total US emissions have increased by 13 percent from 1990 to 2017 and emissions decreased from 2016 to 2017 by 05 percent (355 MMT CO2 Eq) The decrease in total greenhouse gas emissions between 2016 and 2017 was driven in part by a decrease in CO2 emissions from fossil fuel combustion The decrease in CO2 emissions from fossil fuel combustion was a result of multiple factors including a continued shift from coal to natural gas and increased use of renewable energy in the electric power sector and milder weather that contributed to less overall electricity use
Relative to 1990 the baseline for this Inventory gross emissions in 2017 are higher by 13 percent down from a high of 157 percent above 1990 levels in 2007 Overall net emissions in 2017 were 130 percent below 2005 levels as shown in Table ES-2 Figure ES-1 through Figure ES-3 illustrate the overall trends in total US emissions by gas annual changes and absolute change since 1990 and Table ES-2 provides a detailed summary of gross US greenhouse gas emissions and sinks for 1990 through 2017 Note unless otherwise stated all tables and figures provide total gross emissions and exclude the greenhouse gas fluxes from the Land Use Land-Use Change and Forestry (LULUCF) sector (see Section ES3 Overview of Sector Emissions and Trends)
Figure ES-1 Gross US Greenhouse Gas Emissions by Gas (MMT CO2 Eq)
11 The gross emissions total presented in this report for the United States excludes emissions and removals from Land Use Land-Use Change and Forestry (LULUCF) The net emissions total presented in this report for the United States includes emissions and removals from LULUCF
httpswwwepagovsitesproductionfiles2019-04documentsus-ghg-inventory-2019-main-textpdf September 2019
This reflects fracking recession technical progress off-shoring ofmanufacturing Emissions are likely up since 2017
Emissions
Emissions per person
Itrsquos also interesting to look at the country by country breakdown interms of emissions per capita
IPCC 2007 Mitigation fig SPM3a
As of 2012 US had 454 tons C person and for India this numberwas 046 China was 18(httpcdiacornlgovtrendsemistop2011cap)
Emissions
The problem of stabilizing atmospheric CO2Emissions are about 13Gt C per year
The ocean and biosphere absorb about 45 of emissions (sofar)
This means the ocean and biosphere absorb 13 times 045 asymp 6GtC per year
As a rough guess this means that reducing emissions to 6GtC per year will stabilize atmospheric CO2 (but not climate)
This involves a 55 decrease For an average American thismeans this means reducing emissions from 45 tons per yearto about 20 if US share of total emissions stays constant Ifemissions are allocated equally to each of the worldrsquos 74bpeople then each of us gets 6Gt C 74b people or about 08ton This is an 82 decrease for the average American It isalso about the twice the level of the average Indian and halfthat of the average Chinese
Emissions
Summary
2013 emissions of CO2e were about 49Gt Of this 35Gt wasCO2 and of this about 30Gt from fossil fuels and 5Gt fromland use change and agriculture This is E in our model
Emission are growing rapidly about 2year between 2000and 2010 1970 CO2e was 30Gt
2010 CO2e 14 transport 18 buildings 21 industry 24AFOLU We could use this to calculate refinements of ρ5
The countries responsible for most of the stock are not thecountries responsible for most of the flow
Per capita emissions vary by a factor of about 10 between richand poor countries
There has been a decline in US emissions since 2008 due tofracking recession technical progress off shoring
Peak oil
Will we run out of fossil fuel INot soon enough to matter
0
200
400
600
800
Estimated Reserves
Emissions to Date
Gig
aton
s C
arbo
n
Oil Gas Coal Land Use
EIA
IPCCEIA
IPCC
100
200
300
Em
itted
CO
2 (p
pm)
0
200
400
600
800
We have oceans of coal and lots of oil and these figures predateUS fracking
Peak oil
Will we run out of fossil fuel II
Conclusion
Conclusion I
Here is where we stand with our model
maxIM
u(c1 c2) (14)
st W = c1 + I + M (15)
c2 = (1 + r)I minus γ(T2 minus T1)I (16)
E = (1 minus ρ4MW
)(ρ5(c1 + I)) (17)
P2 = ρ0E + P1 (18)
T2 = ρ1(P2 minus P1) + T1 (19)
We have enough pieces filled in to permit you to calculate theimpact on future climate of particular sorts of current consumptioneg burning a tank of propane on your bbq Wersquoll next start
Conclusion
Conclusion II
thinking about the effect of climate change on production γthough wersquoll make an aside to talk about measurement error first
Conclusion
Conclusion III
Each ppm of atmospheric CO2 corresponds to about 212 Gt C
and 778 Gt of CO2 Pay attention to the units people use
Not all gases are equal in their green house potential CO2 ismost common and most important but other gases are moreimportant per unit of emissions
Over the past 50 years about 55 of each emitted Gt of C
has stayed in the atmosphere The rest has been absorbed byland or oceans Thus it takes about 38 Gt C per 1ppm ofatmospheric CO2
Conclusion
Conclusion IV
Emissions are about 13Gt C for 2013 The rate at whichatmospheric CO2 is increasing has risen from about 1ppmyr1960s to 2ppm for 2000rsquos Since there is lots of fuel weshould expect atmospheric CO2 to continue to increase and atan increasing rate lsquobusiness as usual scenarios call foratmospheric CO2e gt 800 within 100 years
Not all countries are the same They are responsible fordifferent shares have different per capita emissions useemission more or less efficiently and are responsible fordifferent shares of historical emissions These factors are veryimportant obstacles to international agreements and alsosuggest the need for a richer model
Conclusion
Conclusion V
Steady state CO2 emissions are probably very small Sternsuggests less than 13 of current Our calculations suggest(1-055)=45
Consumption and emissions
Emissions for particular activities IV
For thinking about fracking also consider the following
Consumption and emissions
Global emissions per unit of consumption ca 2013
Using these sorts of particular numbers together with informationabout aggregate consumption one can calculate world emissions
Global annual emissions ca 2013 are about 49Gt CO2e or49 times 12
44 sim 133 Gt C (more on this later)
World GDP in 2013 is about 77 trillion USD (NB this is W inour model)
Dividingwe have 133times109 tons C77times1012000USD = 133
7700ton CUSD sim 017 kg C
USD (1 ton= 1000 kg) Multiply by 4412 for CO2 instead of C
Recall the third equation from our global warming model
E = (1 minus ρ4MW
)(ρ5(c1 + I)) (7)
Wersquove just calculated ρ5 Why is this sloppy
Consumption and emissions
Emissions per unit of consumption by countryItrsquos also interesting to look at the country by countrybreakdown(ca 2004) The US and Canada make a lot of stuffper ton of emissions
IPCC 2007 Mitigation fig SPM3b
What if China and Africa made same output at USCAemission rates This is why technology transfer is importantCompare 068 kg CO2e per dollar ca 2004 to my calculationof 017 kg C per dollar 2013 How important is technicalprogress
Consumption and emissions
Technological progress I
httpwww3epagovclimatechangescienceindicatorsghgus-ghg-emissionshtml January 2016
Consumption and emissions
Technological progress II
Nordhaus does this calculation every year country by country
Russia
India
World
EU
US
China
Consumption and emissions
Emissions - Summary
Wersquove now calculated ρ5 emissions per GDP at about 017kgC per dollar ca 2013Looking at the data a little more carefully highlights twodeficiencies on our model
Technological progress is at work so this ratio changes overtimeThere are huge difference across places in this ratio
This highlights the importance of technological progress andtechnology transfer in solving the problem of climate change
Wersquoll address this when we get to the Nordhaus model
Emissions
Emissions trends and levels
Recall
maxIM
u(c1 c2) (8)
st W = c1 + I + M (9)
c2 = (1 + r)I minus γ(T2 minus T1)I (10)
E = (1 minus ρ4MW
)(ρ5(c1 + I)) (11)
P2 = ρ0E + P1 (12)
T2 = ρ1(P2 minus P1) + T1 (13)
Wersquove filled in a bit more The next step is to look at E This meanslooking at trends and levels in CO2 emissions
Emissions
CO2e 1970-2010
IPCC 2013 WG3 fig TS1
Right panel gives confidence bounds for 2010 49Gt CO2e in 2010
Emissions
CO2 by purpose and country income 1750-2010
IPCC 2013 WG3 fig TS2
Emissions
Hansenrsquos version of the same thing
Flow StockHansen 2009 fig 27
Contributions to stock and flow are very different At thenegotiating table developing countries want the right to emit sinceeveryone else had their turn
Emissions
2010 CO2e by purpose
IPCC 2013 WG3 fig TS3
Emissions
2010 CO2e by purpose and country income
IPCC 2013 WG3 fig TS3
Emissions
US 1990-2017 CO2e
ES-4 Inventory of US Greenhouse Gas Emissions and Sinks 1990ndash2017
ES2 Recent Trends in US Greenhouse Gas Emissions and Sinks
In 2017 total gross US greenhouse gas emissions were 64567 MMT or million metric tons of carbon dioxide (CO2) Eq11 Total US emissions have increased by 13 percent from 1990 to 2017 and emissions decreased from 2016 to 2017 by 05 percent (355 MMT CO2 Eq) The decrease in total greenhouse gas emissions between 2016 and 2017 was driven in part by a decrease in CO2 emissions from fossil fuel combustion The decrease in CO2 emissions from fossil fuel combustion was a result of multiple factors including a continued shift from coal to natural gas and increased use of renewable energy in the electric power sector and milder weather that contributed to less overall electricity use
Relative to 1990 the baseline for this Inventory gross emissions in 2017 are higher by 13 percent down from a high of 157 percent above 1990 levels in 2007 Overall net emissions in 2017 were 130 percent below 2005 levels as shown in Table ES-2 Figure ES-1 through Figure ES-3 illustrate the overall trends in total US emissions by gas annual changes and absolute change since 1990 and Table ES-2 provides a detailed summary of gross US greenhouse gas emissions and sinks for 1990 through 2017 Note unless otherwise stated all tables and figures provide total gross emissions and exclude the greenhouse gas fluxes from the Land Use Land-Use Change and Forestry (LULUCF) sector (see Section ES3 Overview of Sector Emissions and Trends)
Figure ES-1 Gross US Greenhouse Gas Emissions by Gas (MMT CO2 Eq)
11 The gross emissions total presented in this report for the United States excludes emissions and removals from Land Use Land-Use Change and Forestry (LULUCF) The net emissions total presented in this report for the United States includes emissions and removals from LULUCF
httpswwwepagovsitesproductionfiles2019-04documentsus-ghg-inventory-2019-main-textpdf September 2019
This reflects fracking recession technical progress off-shoring ofmanufacturing Emissions are likely up since 2017
Emissions
Emissions per person
Itrsquos also interesting to look at the country by country breakdown interms of emissions per capita
IPCC 2007 Mitigation fig SPM3a
As of 2012 US had 454 tons C person and for India this numberwas 046 China was 18(httpcdiacornlgovtrendsemistop2011cap)
Emissions
The problem of stabilizing atmospheric CO2Emissions are about 13Gt C per year
The ocean and biosphere absorb about 45 of emissions (sofar)
This means the ocean and biosphere absorb 13 times 045 asymp 6GtC per year
As a rough guess this means that reducing emissions to 6GtC per year will stabilize atmospheric CO2 (but not climate)
This involves a 55 decrease For an average American thismeans this means reducing emissions from 45 tons per yearto about 20 if US share of total emissions stays constant Ifemissions are allocated equally to each of the worldrsquos 74bpeople then each of us gets 6Gt C 74b people or about 08ton This is an 82 decrease for the average American It isalso about the twice the level of the average Indian and halfthat of the average Chinese
Emissions
Summary
2013 emissions of CO2e were about 49Gt Of this 35Gt wasCO2 and of this about 30Gt from fossil fuels and 5Gt fromland use change and agriculture This is E in our model
Emission are growing rapidly about 2year between 2000and 2010 1970 CO2e was 30Gt
2010 CO2e 14 transport 18 buildings 21 industry 24AFOLU We could use this to calculate refinements of ρ5
The countries responsible for most of the stock are not thecountries responsible for most of the flow
Per capita emissions vary by a factor of about 10 between richand poor countries
There has been a decline in US emissions since 2008 due tofracking recession technical progress off shoring
Peak oil
Will we run out of fossil fuel INot soon enough to matter
0
200
400
600
800
Estimated Reserves
Emissions to Date
Gig
aton
s C
arbo
n
Oil Gas Coal Land Use
EIA
IPCCEIA
IPCC
100
200
300
Em
itted
CO
2 (p
pm)
0
200
400
600
800
We have oceans of coal and lots of oil and these figures predateUS fracking
Peak oil
Will we run out of fossil fuel II
Conclusion
Conclusion I
Here is where we stand with our model
maxIM
u(c1 c2) (14)
st W = c1 + I + M (15)
c2 = (1 + r)I minus γ(T2 minus T1)I (16)
E = (1 minus ρ4MW
)(ρ5(c1 + I)) (17)
P2 = ρ0E + P1 (18)
T2 = ρ1(P2 minus P1) + T1 (19)
We have enough pieces filled in to permit you to calculate theimpact on future climate of particular sorts of current consumptioneg burning a tank of propane on your bbq Wersquoll next start
Conclusion
Conclusion II
thinking about the effect of climate change on production γthough wersquoll make an aside to talk about measurement error first
Conclusion
Conclusion III
Each ppm of atmospheric CO2 corresponds to about 212 Gt C
and 778 Gt of CO2 Pay attention to the units people use
Not all gases are equal in their green house potential CO2 ismost common and most important but other gases are moreimportant per unit of emissions
Over the past 50 years about 55 of each emitted Gt of C
has stayed in the atmosphere The rest has been absorbed byland or oceans Thus it takes about 38 Gt C per 1ppm ofatmospheric CO2
Conclusion
Conclusion IV
Emissions are about 13Gt C for 2013 The rate at whichatmospheric CO2 is increasing has risen from about 1ppmyr1960s to 2ppm for 2000rsquos Since there is lots of fuel weshould expect atmospheric CO2 to continue to increase and atan increasing rate lsquobusiness as usual scenarios call foratmospheric CO2e gt 800 within 100 years
Not all countries are the same They are responsible fordifferent shares have different per capita emissions useemission more or less efficiently and are responsible fordifferent shares of historical emissions These factors are veryimportant obstacles to international agreements and alsosuggest the need for a richer model
Conclusion
Conclusion V
Steady state CO2 emissions are probably very small Sternsuggests less than 13 of current Our calculations suggest(1-055)=45
Consumption and emissions
Global emissions per unit of consumption ca 2013
Using these sorts of particular numbers together with informationabout aggregate consumption one can calculate world emissions
Global annual emissions ca 2013 are about 49Gt CO2e or49 times 12
44 sim 133 Gt C (more on this later)
World GDP in 2013 is about 77 trillion USD (NB this is W inour model)
Dividingwe have 133times109 tons C77times1012000USD = 133
7700ton CUSD sim 017 kg C
USD (1 ton= 1000 kg) Multiply by 4412 for CO2 instead of C
Recall the third equation from our global warming model
E = (1 minus ρ4MW
)(ρ5(c1 + I)) (7)
Wersquove just calculated ρ5 Why is this sloppy
Consumption and emissions
Emissions per unit of consumption by countryItrsquos also interesting to look at the country by countrybreakdown(ca 2004) The US and Canada make a lot of stuffper ton of emissions
IPCC 2007 Mitigation fig SPM3b
What if China and Africa made same output at USCAemission rates This is why technology transfer is importantCompare 068 kg CO2e per dollar ca 2004 to my calculationof 017 kg C per dollar 2013 How important is technicalprogress
Consumption and emissions
Technological progress I
httpwww3epagovclimatechangescienceindicatorsghgus-ghg-emissionshtml January 2016
Consumption and emissions
Technological progress II
Nordhaus does this calculation every year country by country
Russia
India
World
EU
US
China
Consumption and emissions
Emissions - Summary
Wersquove now calculated ρ5 emissions per GDP at about 017kgC per dollar ca 2013Looking at the data a little more carefully highlights twodeficiencies on our model
Technological progress is at work so this ratio changes overtimeThere are huge difference across places in this ratio
This highlights the importance of technological progress andtechnology transfer in solving the problem of climate change
Wersquoll address this when we get to the Nordhaus model
Emissions
Emissions trends and levels
Recall
maxIM
u(c1 c2) (8)
st W = c1 + I + M (9)
c2 = (1 + r)I minus γ(T2 minus T1)I (10)
E = (1 minus ρ4MW
)(ρ5(c1 + I)) (11)
P2 = ρ0E + P1 (12)
T2 = ρ1(P2 minus P1) + T1 (13)
Wersquove filled in a bit more The next step is to look at E This meanslooking at trends and levels in CO2 emissions
Emissions
CO2e 1970-2010
IPCC 2013 WG3 fig TS1
Right panel gives confidence bounds for 2010 49Gt CO2e in 2010
Emissions
CO2 by purpose and country income 1750-2010
IPCC 2013 WG3 fig TS2
Emissions
Hansenrsquos version of the same thing
Flow StockHansen 2009 fig 27
Contributions to stock and flow are very different At thenegotiating table developing countries want the right to emit sinceeveryone else had their turn
Emissions
2010 CO2e by purpose
IPCC 2013 WG3 fig TS3
Emissions
2010 CO2e by purpose and country income
IPCC 2013 WG3 fig TS3
Emissions
US 1990-2017 CO2e
ES-4 Inventory of US Greenhouse Gas Emissions and Sinks 1990ndash2017
ES2 Recent Trends in US Greenhouse Gas Emissions and Sinks
In 2017 total gross US greenhouse gas emissions were 64567 MMT or million metric tons of carbon dioxide (CO2) Eq11 Total US emissions have increased by 13 percent from 1990 to 2017 and emissions decreased from 2016 to 2017 by 05 percent (355 MMT CO2 Eq) The decrease in total greenhouse gas emissions between 2016 and 2017 was driven in part by a decrease in CO2 emissions from fossil fuel combustion The decrease in CO2 emissions from fossil fuel combustion was a result of multiple factors including a continued shift from coal to natural gas and increased use of renewable energy in the electric power sector and milder weather that contributed to less overall electricity use
Relative to 1990 the baseline for this Inventory gross emissions in 2017 are higher by 13 percent down from a high of 157 percent above 1990 levels in 2007 Overall net emissions in 2017 were 130 percent below 2005 levels as shown in Table ES-2 Figure ES-1 through Figure ES-3 illustrate the overall trends in total US emissions by gas annual changes and absolute change since 1990 and Table ES-2 provides a detailed summary of gross US greenhouse gas emissions and sinks for 1990 through 2017 Note unless otherwise stated all tables and figures provide total gross emissions and exclude the greenhouse gas fluxes from the Land Use Land-Use Change and Forestry (LULUCF) sector (see Section ES3 Overview of Sector Emissions and Trends)
Figure ES-1 Gross US Greenhouse Gas Emissions by Gas (MMT CO2 Eq)
11 The gross emissions total presented in this report for the United States excludes emissions and removals from Land Use Land-Use Change and Forestry (LULUCF) The net emissions total presented in this report for the United States includes emissions and removals from LULUCF
httpswwwepagovsitesproductionfiles2019-04documentsus-ghg-inventory-2019-main-textpdf September 2019
This reflects fracking recession technical progress off-shoring ofmanufacturing Emissions are likely up since 2017
Emissions
Emissions per person
Itrsquos also interesting to look at the country by country breakdown interms of emissions per capita
IPCC 2007 Mitigation fig SPM3a
As of 2012 US had 454 tons C person and for India this numberwas 046 China was 18(httpcdiacornlgovtrendsemistop2011cap)
Emissions
The problem of stabilizing atmospheric CO2Emissions are about 13Gt C per year
The ocean and biosphere absorb about 45 of emissions (sofar)
This means the ocean and biosphere absorb 13 times 045 asymp 6GtC per year
As a rough guess this means that reducing emissions to 6GtC per year will stabilize atmospheric CO2 (but not climate)
This involves a 55 decrease For an average American thismeans this means reducing emissions from 45 tons per yearto about 20 if US share of total emissions stays constant Ifemissions are allocated equally to each of the worldrsquos 74bpeople then each of us gets 6Gt C 74b people or about 08ton This is an 82 decrease for the average American It isalso about the twice the level of the average Indian and halfthat of the average Chinese
Emissions
Summary
2013 emissions of CO2e were about 49Gt Of this 35Gt wasCO2 and of this about 30Gt from fossil fuels and 5Gt fromland use change and agriculture This is E in our model
Emission are growing rapidly about 2year between 2000and 2010 1970 CO2e was 30Gt
2010 CO2e 14 transport 18 buildings 21 industry 24AFOLU We could use this to calculate refinements of ρ5
The countries responsible for most of the stock are not thecountries responsible for most of the flow
Per capita emissions vary by a factor of about 10 between richand poor countries
There has been a decline in US emissions since 2008 due tofracking recession technical progress off shoring
Peak oil
Will we run out of fossil fuel INot soon enough to matter
0
200
400
600
800
Estimated Reserves
Emissions to Date
Gig
aton
s C
arbo
n
Oil Gas Coal Land Use
EIA
IPCCEIA
IPCC
100
200
300
Em
itted
CO
2 (p
pm)
0
200
400
600
800
We have oceans of coal and lots of oil and these figures predateUS fracking
Peak oil
Will we run out of fossil fuel II
Conclusion
Conclusion I
Here is where we stand with our model
maxIM
u(c1 c2) (14)
st W = c1 + I + M (15)
c2 = (1 + r)I minus γ(T2 minus T1)I (16)
E = (1 minus ρ4MW
)(ρ5(c1 + I)) (17)
P2 = ρ0E + P1 (18)
T2 = ρ1(P2 minus P1) + T1 (19)
We have enough pieces filled in to permit you to calculate theimpact on future climate of particular sorts of current consumptioneg burning a tank of propane on your bbq Wersquoll next start
Conclusion
Conclusion II
thinking about the effect of climate change on production γthough wersquoll make an aside to talk about measurement error first
Conclusion
Conclusion III
Each ppm of atmospheric CO2 corresponds to about 212 Gt C
and 778 Gt of CO2 Pay attention to the units people use
Not all gases are equal in their green house potential CO2 ismost common and most important but other gases are moreimportant per unit of emissions
Over the past 50 years about 55 of each emitted Gt of C
has stayed in the atmosphere The rest has been absorbed byland or oceans Thus it takes about 38 Gt C per 1ppm ofatmospheric CO2
Conclusion
Conclusion IV
Emissions are about 13Gt C for 2013 The rate at whichatmospheric CO2 is increasing has risen from about 1ppmyr1960s to 2ppm for 2000rsquos Since there is lots of fuel weshould expect atmospheric CO2 to continue to increase and atan increasing rate lsquobusiness as usual scenarios call foratmospheric CO2e gt 800 within 100 years
Not all countries are the same They are responsible fordifferent shares have different per capita emissions useemission more or less efficiently and are responsible fordifferent shares of historical emissions These factors are veryimportant obstacles to international agreements and alsosuggest the need for a richer model
Conclusion
Conclusion V
Steady state CO2 emissions are probably very small Sternsuggests less than 13 of current Our calculations suggest(1-055)=45
Consumption and emissions
Emissions per unit of consumption by countryItrsquos also interesting to look at the country by countrybreakdown(ca 2004) The US and Canada make a lot of stuffper ton of emissions
IPCC 2007 Mitigation fig SPM3b
What if China and Africa made same output at USCAemission rates This is why technology transfer is importantCompare 068 kg CO2e per dollar ca 2004 to my calculationof 017 kg C per dollar 2013 How important is technicalprogress
Consumption and emissions
Technological progress I
httpwww3epagovclimatechangescienceindicatorsghgus-ghg-emissionshtml January 2016
Consumption and emissions
Technological progress II
Nordhaus does this calculation every year country by country
Russia
India
World
EU
US
China
Consumption and emissions
Emissions - Summary
Wersquove now calculated ρ5 emissions per GDP at about 017kgC per dollar ca 2013Looking at the data a little more carefully highlights twodeficiencies on our model
Technological progress is at work so this ratio changes overtimeThere are huge difference across places in this ratio
This highlights the importance of technological progress andtechnology transfer in solving the problem of climate change
Wersquoll address this when we get to the Nordhaus model
Emissions
Emissions trends and levels
Recall
maxIM
u(c1 c2) (8)
st W = c1 + I + M (9)
c2 = (1 + r)I minus γ(T2 minus T1)I (10)
E = (1 minus ρ4MW
)(ρ5(c1 + I)) (11)
P2 = ρ0E + P1 (12)
T2 = ρ1(P2 minus P1) + T1 (13)
Wersquove filled in a bit more The next step is to look at E This meanslooking at trends and levels in CO2 emissions
Emissions
CO2e 1970-2010
IPCC 2013 WG3 fig TS1
Right panel gives confidence bounds for 2010 49Gt CO2e in 2010
Emissions
CO2 by purpose and country income 1750-2010
IPCC 2013 WG3 fig TS2
Emissions
Hansenrsquos version of the same thing
Flow StockHansen 2009 fig 27
Contributions to stock and flow are very different At thenegotiating table developing countries want the right to emit sinceeveryone else had their turn
Emissions
2010 CO2e by purpose
IPCC 2013 WG3 fig TS3
Emissions
2010 CO2e by purpose and country income
IPCC 2013 WG3 fig TS3
Emissions
US 1990-2017 CO2e
ES-4 Inventory of US Greenhouse Gas Emissions and Sinks 1990ndash2017
ES2 Recent Trends in US Greenhouse Gas Emissions and Sinks
In 2017 total gross US greenhouse gas emissions were 64567 MMT or million metric tons of carbon dioxide (CO2) Eq11 Total US emissions have increased by 13 percent from 1990 to 2017 and emissions decreased from 2016 to 2017 by 05 percent (355 MMT CO2 Eq) The decrease in total greenhouse gas emissions between 2016 and 2017 was driven in part by a decrease in CO2 emissions from fossil fuel combustion The decrease in CO2 emissions from fossil fuel combustion was a result of multiple factors including a continued shift from coal to natural gas and increased use of renewable energy in the electric power sector and milder weather that contributed to less overall electricity use
Relative to 1990 the baseline for this Inventory gross emissions in 2017 are higher by 13 percent down from a high of 157 percent above 1990 levels in 2007 Overall net emissions in 2017 were 130 percent below 2005 levels as shown in Table ES-2 Figure ES-1 through Figure ES-3 illustrate the overall trends in total US emissions by gas annual changes and absolute change since 1990 and Table ES-2 provides a detailed summary of gross US greenhouse gas emissions and sinks for 1990 through 2017 Note unless otherwise stated all tables and figures provide total gross emissions and exclude the greenhouse gas fluxes from the Land Use Land-Use Change and Forestry (LULUCF) sector (see Section ES3 Overview of Sector Emissions and Trends)
Figure ES-1 Gross US Greenhouse Gas Emissions by Gas (MMT CO2 Eq)
11 The gross emissions total presented in this report for the United States excludes emissions and removals from Land Use Land-Use Change and Forestry (LULUCF) The net emissions total presented in this report for the United States includes emissions and removals from LULUCF
httpswwwepagovsitesproductionfiles2019-04documentsus-ghg-inventory-2019-main-textpdf September 2019
This reflects fracking recession technical progress off-shoring ofmanufacturing Emissions are likely up since 2017
Emissions
Emissions per person
Itrsquos also interesting to look at the country by country breakdown interms of emissions per capita
IPCC 2007 Mitigation fig SPM3a
As of 2012 US had 454 tons C person and for India this numberwas 046 China was 18(httpcdiacornlgovtrendsemistop2011cap)
Emissions
The problem of stabilizing atmospheric CO2Emissions are about 13Gt C per year
The ocean and biosphere absorb about 45 of emissions (sofar)
This means the ocean and biosphere absorb 13 times 045 asymp 6GtC per year
As a rough guess this means that reducing emissions to 6GtC per year will stabilize atmospheric CO2 (but not climate)
This involves a 55 decrease For an average American thismeans this means reducing emissions from 45 tons per yearto about 20 if US share of total emissions stays constant Ifemissions are allocated equally to each of the worldrsquos 74bpeople then each of us gets 6Gt C 74b people or about 08ton This is an 82 decrease for the average American It isalso about the twice the level of the average Indian and halfthat of the average Chinese
Emissions
Summary
2013 emissions of CO2e were about 49Gt Of this 35Gt wasCO2 and of this about 30Gt from fossil fuels and 5Gt fromland use change and agriculture This is E in our model
Emission are growing rapidly about 2year between 2000and 2010 1970 CO2e was 30Gt
2010 CO2e 14 transport 18 buildings 21 industry 24AFOLU We could use this to calculate refinements of ρ5
The countries responsible for most of the stock are not thecountries responsible for most of the flow
Per capita emissions vary by a factor of about 10 between richand poor countries
There has been a decline in US emissions since 2008 due tofracking recession technical progress off shoring
Peak oil
Will we run out of fossil fuel INot soon enough to matter
0
200
400
600
800
Estimated Reserves
Emissions to Date
Gig
aton
s C
arbo
n
Oil Gas Coal Land Use
EIA
IPCCEIA
IPCC
100
200
300
Em
itted
CO
2 (p
pm)
0
200
400
600
800
We have oceans of coal and lots of oil and these figures predateUS fracking
Peak oil
Will we run out of fossil fuel II
Conclusion
Conclusion I
Here is where we stand with our model
maxIM
u(c1 c2) (14)
st W = c1 + I + M (15)
c2 = (1 + r)I minus γ(T2 minus T1)I (16)
E = (1 minus ρ4MW
)(ρ5(c1 + I)) (17)
P2 = ρ0E + P1 (18)
T2 = ρ1(P2 minus P1) + T1 (19)
We have enough pieces filled in to permit you to calculate theimpact on future climate of particular sorts of current consumptioneg burning a tank of propane on your bbq Wersquoll next start
Conclusion
Conclusion II
thinking about the effect of climate change on production γthough wersquoll make an aside to talk about measurement error first
Conclusion
Conclusion III
Each ppm of atmospheric CO2 corresponds to about 212 Gt C
and 778 Gt of CO2 Pay attention to the units people use
Not all gases are equal in their green house potential CO2 ismost common and most important but other gases are moreimportant per unit of emissions
Over the past 50 years about 55 of each emitted Gt of C
has stayed in the atmosphere The rest has been absorbed byland or oceans Thus it takes about 38 Gt C per 1ppm ofatmospheric CO2
Conclusion
Conclusion IV
Emissions are about 13Gt C for 2013 The rate at whichatmospheric CO2 is increasing has risen from about 1ppmyr1960s to 2ppm for 2000rsquos Since there is lots of fuel weshould expect atmospheric CO2 to continue to increase and atan increasing rate lsquobusiness as usual scenarios call foratmospheric CO2e gt 800 within 100 years
Not all countries are the same They are responsible fordifferent shares have different per capita emissions useemission more or less efficiently and are responsible fordifferent shares of historical emissions These factors are veryimportant obstacles to international agreements and alsosuggest the need for a richer model
Conclusion
Conclusion V
Steady state CO2 emissions are probably very small Sternsuggests less than 13 of current Our calculations suggest(1-055)=45
Consumption and emissions
Technological progress I
httpwww3epagovclimatechangescienceindicatorsghgus-ghg-emissionshtml January 2016
Consumption and emissions
Technological progress II
Nordhaus does this calculation every year country by country
Russia
India
World
EU
US
China
Consumption and emissions
Emissions - Summary
Wersquove now calculated ρ5 emissions per GDP at about 017kgC per dollar ca 2013Looking at the data a little more carefully highlights twodeficiencies on our model
Technological progress is at work so this ratio changes overtimeThere are huge difference across places in this ratio
This highlights the importance of technological progress andtechnology transfer in solving the problem of climate change
Wersquoll address this when we get to the Nordhaus model
Emissions
Emissions trends and levels
Recall
maxIM
u(c1 c2) (8)
st W = c1 + I + M (9)
c2 = (1 + r)I minus γ(T2 minus T1)I (10)
E = (1 minus ρ4MW
)(ρ5(c1 + I)) (11)
P2 = ρ0E + P1 (12)
T2 = ρ1(P2 minus P1) + T1 (13)
Wersquove filled in a bit more The next step is to look at E This meanslooking at trends and levels in CO2 emissions
Emissions
CO2e 1970-2010
IPCC 2013 WG3 fig TS1
Right panel gives confidence bounds for 2010 49Gt CO2e in 2010
Emissions
CO2 by purpose and country income 1750-2010
IPCC 2013 WG3 fig TS2
Emissions
Hansenrsquos version of the same thing
Flow StockHansen 2009 fig 27
Contributions to stock and flow are very different At thenegotiating table developing countries want the right to emit sinceeveryone else had their turn
Emissions
2010 CO2e by purpose
IPCC 2013 WG3 fig TS3
Emissions
2010 CO2e by purpose and country income
IPCC 2013 WG3 fig TS3
Emissions
US 1990-2017 CO2e
ES-4 Inventory of US Greenhouse Gas Emissions and Sinks 1990ndash2017
ES2 Recent Trends in US Greenhouse Gas Emissions and Sinks
In 2017 total gross US greenhouse gas emissions were 64567 MMT or million metric tons of carbon dioxide (CO2) Eq11 Total US emissions have increased by 13 percent from 1990 to 2017 and emissions decreased from 2016 to 2017 by 05 percent (355 MMT CO2 Eq) The decrease in total greenhouse gas emissions between 2016 and 2017 was driven in part by a decrease in CO2 emissions from fossil fuel combustion The decrease in CO2 emissions from fossil fuel combustion was a result of multiple factors including a continued shift from coal to natural gas and increased use of renewable energy in the electric power sector and milder weather that contributed to less overall electricity use
Relative to 1990 the baseline for this Inventory gross emissions in 2017 are higher by 13 percent down from a high of 157 percent above 1990 levels in 2007 Overall net emissions in 2017 were 130 percent below 2005 levels as shown in Table ES-2 Figure ES-1 through Figure ES-3 illustrate the overall trends in total US emissions by gas annual changes and absolute change since 1990 and Table ES-2 provides a detailed summary of gross US greenhouse gas emissions and sinks for 1990 through 2017 Note unless otherwise stated all tables and figures provide total gross emissions and exclude the greenhouse gas fluxes from the Land Use Land-Use Change and Forestry (LULUCF) sector (see Section ES3 Overview of Sector Emissions and Trends)
Figure ES-1 Gross US Greenhouse Gas Emissions by Gas (MMT CO2 Eq)
11 The gross emissions total presented in this report for the United States excludes emissions and removals from Land Use Land-Use Change and Forestry (LULUCF) The net emissions total presented in this report for the United States includes emissions and removals from LULUCF
httpswwwepagovsitesproductionfiles2019-04documentsus-ghg-inventory-2019-main-textpdf September 2019
This reflects fracking recession technical progress off-shoring ofmanufacturing Emissions are likely up since 2017
Emissions
Emissions per person
Itrsquos also interesting to look at the country by country breakdown interms of emissions per capita
IPCC 2007 Mitigation fig SPM3a
As of 2012 US had 454 tons C person and for India this numberwas 046 China was 18(httpcdiacornlgovtrendsemistop2011cap)
Emissions
The problem of stabilizing atmospheric CO2Emissions are about 13Gt C per year
The ocean and biosphere absorb about 45 of emissions (sofar)
This means the ocean and biosphere absorb 13 times 045 asymp 6GtC per year
As a rough guess this means that reducing emissions to 6GtC per year will stabilize atmospheric CO2 (but not climate)
This involves a 55 decrease For an average American thismeans this means reducing emissions from 45 tons per yearto about 20 if US share of total emissions stays constant Ifemissions are allocated equally to each of the worldrsquos 74bpeople then each of us gets 6Gt C 74b people or about 08ton This is an 82 decrease for the average American It isalso about the twice the level of the average Indian and halfthat of the average Chinese
Emissions
Summary
2013 emissions of CO2e were about 49Gt Of this 35Gt wasCO2 and of this about 30Gt from fossil fuels and 5Gt fromland use change and agriculture This is E in our model
Emission are growing rapidly about 2year between 2000and 2010 1970 CO2e was 30Gt
2010 CO2e 14 transport 18 buildings 21 industry 24AFOLU We could use this to calculate refinements of ρ5
The countries responsible for most of the stock are not thecountries responsible for most of the flow
Per capita emissions vary by a factor of about 10 between richand poor countries
There has been a decline in US emissions since 2008 due tofracking recession technical progress off shoring
Peak oil
Will we run out of fossil fuel INot soon enough to matter
0
200
400
600
800
Estimated Reserves
Emissions to Date
Gig
aton
s C
arbo
n
Oil Gas Coal Land Use
EIA
IPCCEIA
IPCC
100
200
300
Em
itted
CO
2 (p
pm)
0
200
400
600
800
We have oceans of coal and lots of oil and these figures predateUS fracking
Peak oil
Will we run out of fossil fuel II
Conclusion
Conclusion I
Here is where we stand with our model
maxIM
u(c1 c2) (14)
st W = c1 + I + M (15)
c2 = (1 + r)I minus γ(T2 minus T1)I (16)
E = (1 minus ρ4MW
)(ρ5(c1 + I)) (17)
P2 = ρ0E + P1 (18)
T2 = ρ1(P2 minus P1) + T1 (19)
We have enough pieces filled in to permit you to calculate theimpact on future climate of particular sorts of current consumptioneg burning a tank of propane on your bbq Wersquoll next start
Conclusion
Conclusion II
thinking about the effect of climate change on production γthough wersquoll make an aside to talk about measurement error first
Conclusion
Conclusion III
Each ppm of atmospheric CO2 corresponds to about 212 Gt C
and 778 Gt of CO2 Pay attention to the units people use
Not all gases are equal in their green house potential CO2 ismost common and most important but other gases are moreimportant per unit of emissions
Over the past 50 years about 55 of each emitted Gt of C
has stayed in the atmosphere The rest has been absorbed byland or oceans Thus it takes about 38 Gt C per 1ppm ofatmospheric CO2
Conclusion
Conclusion IV
Emissions are about 13Gt C for 2013 The rate at whichatmospheric CO2 is increasing has risen from about 1ppmyr1960s to 2ppm for 2000rsquos Since there is lots of fuel weshould expect atmospheric CO2 to continue to increase and atan increasing rate lsquobusiness as usual scenarios call foratmospheric CO2e gt 800 within 100 years
Not all countries are the same They are responsible fordifferent shares have different per capita emissions useemission more or less efficiently and are responsible fordifferent shares of historical emissions These factors are veryimportant obstacles to international agreements and alsosuggest the need for a richer model
Conclusion
Conclusion V
Steady state CO2 emissions are probably very small Sternsuggests less than 13 of current Our calculations suggest(1-055)=45
Consumption and emissions
Technological progress II
Nordhaus does this calculation every year country by country
Russia
India
World
EU
US
China
Consumption and emissions
Emissions - Summary
Wersquove now calculated ρ5 emissions per GDP at about 017kgC per dollar ca 2013Looking at the data a little more carefully highlights twodeficiencies on our model
Technological progress is at work so this ratio changes overtimeThere are huge difference across places in this ratio
This highlights the importance of technological progress andtechnology transfer in solving the problem of climate change
Wersquoll address this when we get to the Nordhaus model
Emissions
Emissions trends and levels
Recall
maxIM
u(c1 c2) (8)
st W = c1 + I + M (9)
c2 = (1 + r)I minus γ(T2 minus T1)I (10)
E = (1 minus ρ4MW
)(ρ5(c1 + I)) (11)
P2 = ρ0E + P1 (12)
T2 = ρ1(P2 minus P1) + T1 (13)
Wersquove filled in a bit more The next step is to look at E This meanslooking at trends and levels in CO2 emissions
Emissions
CO2e 1970-2010
IPCC 2013 WG3 fig TS1
Right panel gives confidence bounds for 2010 49Gt CO2e in 2010
Emissions
CO2 by purpose and country income 1750-2010
IPCC 2013 WG3 fig TS2
Emissions
Hansenrsquos version of the same thing
Flow StockHansen 2009 fig 27
Contributions to stock and flow are very different At thenegotiating table developing countries want the right to emit sinceeveryone else had their turn
Emissions
2010 CO2e by purpose
IPCC 2013 WG3 fig TS3
Emissions
2010 CO2e by purpose and country income
IPCC 2013 WG3 fig TS3
Emissions
US 1990-2017 CO2e
ES-4 Inventory of US Greenhouse Gas Emissions and Sinks 1990ndash2017
ES2 Recent Trends in US Greenhouse Gas Emissions and Sinks
In 2017 total gross US greenhouse gas emissions were 64567 MMT or million metric tons of carbon dioxide (CO2) Eq11 Total US emissions have increased by 13 percent from 1990 to 2017 and emissions decreased from 2016 to 2017 by 05 percent (355 MMT CO2 Eq) The decrease in total greenhouse gas emissions between 2016 and 2017 was driven in part by a decrease in CO2 emissions from fossil fuel combustion The decrease in CO2 emissions from fossil fuel combustion was a result of multiple factors including a continued shift from coal to natural gas and increased use of renewable energy in the electric power sector and milder weather that contributed to less overall electricity use
Relative to 1990 the baseline for this Inventory gross emissions in 2017 are higher by 13 percent down from a high of 157 percent above 1990 levels in 2007 Overall net emissions in 2017 were 130 percent below 2005 levels as shown in Table ES-2 Figure ES-1 through Figure ES-3 illustrate the overall trends in total US emissions by gas annual changes and absolute change since 1990 and Table ES-2 provides a detailed summary of gross US greenhouse gas emissions and sinks for 1990 through 2017 Note unless otherwise stated all tables and figures provide total gross emissions and exclude the greenhouse gas fluxes from the Land Use Land-Use Change and Forestry (LULUCF) sector (see Section ES3 Overview of Sector Emissions and Trends)
Figure ES-1 Gross US Greenhouse Gas Emissions by Gas (MMT CO2 Eq)
11 The gross emissions total presented in this report for the United States excludes emissions and removals from Land Use Land-Use Change and Forestry (LULUCF) The net emissions total presented in this report for the United States includes emissions and removals from LULUCF
httpswwwepagovsitesproductionfiles2019-04documentsus-ghg-inventory-2019-main-textpdf September 2019
This reflects fracking recession technical progress off-shoring ofmanufacturing Emissions are likely up since 2017
Emissions
Emissions per person
Itrsquos also interesting to look at the country by country breakdown interms of emissions per capita
IPCC 2007 Mitigation fig SPM3a
As of 2012 US had 454 tons C person and for India this numberwas 046 China was 18(httpcdiacornlgovtrendsemistop2011cap)
Emissions
The problem of stabilizing atmospheric CO2Emissions are about 13Gt C per year
The ocean and biosphere absorb about 45 of emissions (sofar)
This means the ocean and biosphere absorb 13 times 045 asymp 6GtC per year
As a rough guess this means that reducing emissions to 6GtC per year will stabilize atmospheric CO2 (but not climate)
This involves a 55 decrease For an average American thismeans this means reducing emissions from 45 tons per yearto about 20 if US share of total emissions stays constant Ifemissions are allocated equally to each of the worldrsquos 74bpeople then each of us gets 6Gt C 74b people or about 08ton This is an 82 decrease for the average American It isalso about the twice the level of the average Indian and halfthat of the average Chinese
Emissions
Summary
2013 emissions of CO2e were about 49Gt Of this 35Gt wasCO2 and of this about 30Gt from fossil fuels and 5Gt fromland use change and agriculture This is E in our model
Emission are growing rapidly about 2year between 2000and 2010 1970 CO2e was 30Gt
2010 CO2e 14 transport 18 buildings 21 industry 24AFOLU We could use this to calculate refinements of ρ5
The countries responsible for most of the stock are not thecountries responsible for most of the flow
Per capita emissions vary by a factor of about 10 between richand poor countries
There has been a decline in US emissions since 2008 due tofracking recession technical progress off shoring
Peak oil
Will we run out of fossil fuel INot soon enough to matter
0
200
400
600
800
Estimated Reserves
Emissions to Date
Gig
aton
s C
arbo
n
Oil Gas Coal Land Use
EIA
IPCCEIA
IPCC
100
200
300
Em
itted
CO
2 (p
pm)
0
200
400
600
800
We have oceans of coal and lots of oil and these figures predateUS fracking
Peak oil
Will we run out of fossil fuel II
Conclusion
Conclusion I
Here is where we stand with our model
maxIM
u(c1 c2) (14)
st W = c1 + I + M (15)
c2 = (1 + r)I minus γ(T2 minus T1)I (16)
E = (1 minus ρ4MW
)(ρ5(c1 + I)) (17)
P2 = ρ0E + P1 (18)
T2 = ρ1(P2 minus P1) + T1 (19)
We have enough pieces filled in to permit you to calculate theimpact on future climate of particular sorts of current consumptioneg burning a tank of propane on your bbq Wersquoll next start
Conclusion
Conclusion II
thinking about the effect of climate change on production γthough wersquoll make an aside to talk about measurement error first
Conclusion
Conclusion III
Each ppm of atmospheric CO2 corresponds to about 212 Gt C
and 778 Gt of CO2 Pay attention to the units people use
Not all gases are equal in their green house potential CO2 ismost common and most important but other gases are moreimportant per unit of emissions
Over the past 50 years about 55 of each emitted Gt of C
has stayed in the atmosphere The rest has been absorbed byland or oceans Thus it takes about 38 Gt C per 1ppm ofatmospheric CO2
Conclusion
Conclusion IV
Emissions are about 13Gt C for 2013 The rate at whichatmospheric CO2 is increasing has risen from about 1ppmyr1960s to 2ppm for 2000rsquos Since there is lots of fuel weshould expect atmospheric CO2 to continue to increase and atan increasing rate lsquobusiness as usual scenarios call foratmospheric CO2e gt 800 within 100 years
Not all countries are the same They are responsible fordifferent shares have different per capita emissions useemission more or less efficiently and are responsible fordifferent shares of historical emissions These factors are veryimportant obstacles to international agreements and alsosuggest the need for a richer model
Conclusion
Conclusion V
Steady state CO2 emissions are probably very small Sternsuggests less than 13 of current Our calculations suggest(1-055)=45
Consumption and emissions
Emissions - Summary
Wersquove now calculated ρ5 emissions per GDP at about 017kgC per dollar ca 2013Looking at the data a little more carefully highlights twodeficiencies on our model
Technological progress is at work so this ratio changes overtimeThere are huge difference across places in this ratio
This highlights the importance of technological progress andtechnology transfer in solving the problem of climate change
Wersquoll address this when we get to the Nordhaus model
Emissions
Emissions trends and levels
Recall
maxIM
u(c1 c2) (8)
st W = c1 + I + M (9)
c2 = (1 + r)I minus γ(T2 minus T1)I (10)
E = (1 minus ρ4MW
)(ρ5(c1 + I)) (11)
P2 = ρ0E + P1 (12)
T2 = ρ1(P2 minus P1) + T1 (13)
Wersquove filled in a bit more The next step is to look at E This meanslooking at trends and levels in CO2 emissions
Emissions
CO2e 1970-2010
IPCC 2013 WG3 fig TS1
Right panel gives confidence bounds for 2010 49Gt CO2e in 2010
Emissions
CO2 by purpose and country income 1750-2010
IPCC 2013 WG3 fig TS2
Emissions
Hansenrsquos version of the same thing
Flow StockHansen 2009 fig 27
Contributions to stock and flow are very different At thenegotiating table developing countries want the right to emit sinceeveryone else had their turn
Emissions
2010 CO2e by purpose
IPCC 2013 WG3 fig TS3
Emissions
2010 CO2e by purpose and country income
IPCC 2013 WG3 fig TS3
Emissions
US 1990-2017 CO2e
ES-4 Inventory of US Greenhouse Gas Emissions and Sinks 1990ndash2017
ES2 Recent Trends in US Greenhouse Gas Emissions and Sinks
In 2017 total gross US greenhouse gas emissions were 64567 MMT or million metric tons of carbon dioxide (CO2) Eq11 Total US emissions have increased by 13 percent from 1990 to 2017 and emissions decreased from 2016 to 2017 by 05 percent (355 MMT CO2 Eq) The decrease in total greenhouse gas emissions between 2016 and 2017 was driven in part by a decrease in CO2 emissions from fossil fuel combustion The decrease in CO2 emissions from fossil fuel combustion was a result of multiple factors including a continued shift from coal to natural gas and increased use of renewable energy in the electric power sector and milder weather that contributed to less overall electricity use
Relative to 1990 the baseline for this Inventory gross emissions in 2017 are higher by 13 percent down from a high of 157 percent above 1990 levels in 2007 Overall net emissions in 2017 were 130 percent below 2005 levels as shown in Table ES-2 Figure ES-1 through Figure ES-3 illustrate the overall trends in total US emissions by gas annual changes and absolute change since 1990 and Table ES-2 provides a detailed summary of gross US greenhouse gas emissions and sinks for 1990 through 2017 Note unless otherwise stated all tables and figures provide total gross emissions and exclude the greenhouse gas fluxes from the Land Use Land-Use Change and Forestry (LULUCF) sector (see Section ES3 Overview of Sector Emissions and Trends)
Figure ES-1 Gross US Greenhouse Gas Emissions by Gas (MMT CO2 Eq)
11 The gross emissions total presented in this report for the United States excludes emissions and removals from Land Use Land-Use Change and Forestry (LULUCF) The net emissions total presented in this report for the United States includes emissions and removals from LULUCF
httpswwwepagovsitesproductionfiles2019-04documentsus-ghg-inventory-2019-main-textpdf September 2019
This reflects fracking recession technical progress off-shoring ofmanufacturing Emissions are likely up since 2017
Emissions
Emissions per person
Itrsquos also interesting to look at the country by country breakdown interms of emissions per capita
IPCC 2007 Mitigation fig SPM3a
As of 2012 US had 454 tons C person and for India this numberwas 046 China was 18(httpcdiacornlgovtrendsemistop2011cap)
Emissions
The problem of stabilizing atmospheric CO2Emissions are about 13Gt C per year
The ocean and biosphere absorb about 45 of emissions (sofar)
This means the ocean and biosphere absorb 13 times 045 asymp 6GtC per year
As a rough guess this means that reducing emissions to 6GtC per year will stabilize atmospheric CO2 (but not climate)
This involves a 55 decrease For an average American thismeans this means reducing emissions from 45 tons per yearto about 20 if US share of total emissions stays constant Ifemissions are allocated equally to each of the worldrsquos 74bpeople then each of us gets 6Gt C 74b people or about 08ton This is an 82 decrease for the average American It isalso about the twice the level of the average Indian and halfthat of the average Chinese
Emissions
Summary
2013 emissions of CO2e were about 49Gt Of this 35Gt wasCO2 and of this about 30Gt from fossil fuels and 5Gt fromland use change and agriculture This is E in our model
Emission are growing rapidly about 2year between 2000and 2010 1970 CO2e was 30Gt
2010 CO2e 14 transport 18 buildings 21 industry 24AFOLU We could use this to calculate refinements of ρ5
The countries responsible for most of the stock are not thecountries responsible for most of the flow
Per capita emissions vary by a factor of about 10 between richand poor countries
There has been a decline in US emissions since 2008 due tofracking recession technical progress off shoring
Peak oil
Will we run out of fossil fuel INot soon enough to matter
0
200
400
600
800
Estimated Reserves
Emissions to Date
Gig
aton
s C
arbo
n
Oil Gas Coal Land Use
EIA
IPCCEIA
IPCC
100
200
300
Em
itted
CO
2 (p
pm)
0
200
400
600
800
We have oceans of coal and lots of oil and these figures predateUS fracking
Peak oil
Will we run out of fossil fuel II
Conclusion
Conclusion I
Here is where we stand with our model
maxIM
u(c1 c2) (14)
st W = c1 + I + M (15)
c2 = (1 + r)I minus γ(T2 minus T1)I (16)
E = (1 minus ρ4MW
)(ρ5(c1 + I)) (17)
P2 = ρ0E + P1 (18)
T2 = ρ1(P2 minus P1) + T1 (19)
We have enough pieces filled in to permit you to calculate theimpact on future climate of particular sorts of current consumptioneg burning a tank of propane on your bbq Wersquoll next start
Conclusion
Conclusion II
thinking about the effect of climate change on production γthough wersquoll make an aside to talk about measurement error first
Conclusion
Conclusion III
Each ppm of atmospheric CO2 corresponds to about 212 Gt C
and 778 Gt of CO2 Pay attention to the units people use
Not all gases are equal in their green house potential CO2 ismost common and most important but other gases are moreimportant per unit of emissions
Over the past 50 years about 55 of each emitted Gt of C
has stayed in the atmosphere The rest has been absorbed byland or oceans Thus it takes about 38 Gt C per 1ppm ofatmospheric CO2
Conclusion
Conclusion IV
Emissions are about 13Gt C for 2013 The rate at whichatmospheric CO2 is increasing has risen from about 1ppmyr1960s to 2ppm for 2000rsquos Since there is lots of fuel weshould expect atmospheric CO2 to continue to increase and atan increasing rate lsquobusiness as usual scenarios call foratmospheric CO2e gt 800 within 100 years
Not all countries are the same They are responsible fordifferent shares have different per capita emissions useemission more or less efficiently and are responsible fordifferent shares of historical emissions These factors are veryimportant obstacles to international agreements and alsosuggest the need for a richer model
Conclusion
Conclusion V
Steady state CO2 emissions are probably very small Sternsuggests less than 13 of current Our calculations suggest(1-055)=45
Emissions
Emissions trends and levels
Recall
maxIM
u(c1 c2) (8)
st W = c1 + I + M (9)
c2 = (1 + r)I minus γ(T2 minus T1)I (10)
E = (1 minus ρ4MW
)(ρ5(c1 + I)) (11)
P2 = ρ0E + P1 (12)
T2 = ρ1(P2 minus P1) + T1 (13)
Wersquove filled in a bit more The next step is to look at E This meanslooking at trends and levels in CO2 emissions
Emissions
CO2e 1970-2010
IPCC 2013 WG3 fig TS1
Right panel gives confidence bounds for 2010 49Gt CO2e in 2010
Emissions
CO2 by purpose and country income 1750-2010
IPCC 2013 WG3 fig TS2
Emissions
Hansenrsquos version of the same thing
Flow StockHansen 2009 fig 27
Contributions to stock and flow are very different At thenegotiating table developing countries want the right to emit sinceeveryone else had their turn
Emissions
2010 CO2e by purpose
IPCC 2013 WG3 fig TS3
Emissions
2010 CO2e by purpose and country income
IPCC 2013 WG3 fig TS3
Emissions
US 1990-2017 CO2e
ES-4 Inventory of US Greenhouse Gas Emissions and Sinks 1990ndash2017
ES2 Recent Trends in US Greenhouse Gas Emissions and Sinks
In 2017 total gross US greenhouse gas emissions were 64567 MMT or million metric tons of carbon dioxide (CO2) Eq11 Total US emissions have increased by 13 percent from 1990 to 2017 and emissions decreased from 2016 to 2017 by 05 percent (355 MMT CO2 Eq) The decrease in total greenhouse gas emissions between 2016 and 2017 was driven in part by a decrease in CO2 emissions from fossil fuel combustion The decrease in CO2 emissions from fossil fuel combustion was a result of multiple factors including a continued shift from coal to natural gas and increased use of renewable energy in the electric power sector and milder weather that contributed to less overall electricity use
Relative to 1990 the baseline for this Inventory gross emissions in 2017 are higher by 13 percent down from a high of 157 percent above 1990 levels in 2007 Overall net emissions in 2017 were 130 percent below 2005 levels as shown in Table ES-2 Figure ES-1 through Figure ES-3 illustrate the overall trends in total US emissions by gas annual changes and absolute change since 1990 and Table ES-2 provides a detailed summary of gross US greenhouse gas emissions and sinks for 1990 through 2017 Note unless otherwise stated all tables and figures provide total gross emissions and exclude the greenhouse gas fluxes from the Land Use Land-Use Change and Forestry (LULUCF) sector (see Section ES3 Overview of Sector Emissions and Trends)
Figure ES-1 Gross US Greenhouse Gas Emissions by Gas (MMT CO2 Eq)
11 The gross emissions total presented in this report for the United States excludes emissions and removals from Land Use Land-Use Change and Forestry (LULUCF) The net emissions total presented in this report for the United States includes emissions and removals from LULUCF
httpswwwepagovsitesproductionfiles2019-04documentsus-ghg-inventory-2019-main-textpdf September 2019
This reflects fracking recession technical progress off-shoring ofmanufacturing Emissions are likely up since 2017
Emissions
Emissions per person
Itrsquos also interesting to look at the country by country breakdown interms of emissions per capita
IPCC 2007 Mitigation fig SPM3a
As of 2012 US had 454 tons C person and for India this numberwas 046 China was 18(httpcdiacornlgovtrendsemistop2011cap)
Emissions
The problem of stabilizing atmospheric CO2Emissions are about 13Gt C per year
The ocean and biosphere absorb about 45 of emissions (sofar)
This means the ocean and biosphere absorb 13 times 045 asymp 6GtC per year
As a rough guess this means that reducing emissions to 6GtC per year will stabilize atmospheric CO2 (but not climate)
This involves a 55 decrease For an average American thismeans this means reducing emissions from 45 tons per yearto about 20 if US share of total emissions stays constant Ifemissions are allocated equally to each of the worldrsquos 74bpeople then each of us gets 6Gt C 74b people or about 08ton This is an 82 decrease for the average American It isalso about the twice the level of the average Indian and halfthat of the average Chinese
Emissions
Summary
2013 emissions of CO2e were about 49Gt Of this 35Gt wasCO2 and of this about 30Gt from fossil fuels and 5Gt fromland use change and agriculture This is E in our model
Emission are growing rapidly about 2year between 2000and 2010 1970 CO2e was 30Gt
2010 CO2e 14 transport 18 buildings 21 industry 24AFOLU We could use this to calculate refinements of ρ5
The countries responsible for most of the stock are not thecountries responsible for most of the flow
Per capita emissions vary by a factor of about 10 between richand poor countries
There has been a decline in US emissions since 2008 due tofracking recession technical progress off shoring
Peak oil
Will we run out of fossil fuel INot soon enough to matter
0
200
400
600
800
Estimated Reserves
Emissions to Date
Gig
aton
s C
arbo
n
Oil Gas Coal Land Use
EIA
IPCCEIA
IPCC
100
200
300
Em
itted
CO
2 (p
pm)
0
200
400
600
800
We have oceans of coal and lots of oil and these figures predateUS fracking
Peak oil
Will we run out of fossil fuel II
Conclusion
Conclusion I
Here is where we stand with our model
maxIM
u(c1 c2) (14)
st W = c1 + I + M (15)
c2 = (1 + r)I minus γ(T2 minus T1)I (16)
E = (1 minus ρ4MW
)(ρ5(c1 + I)) (17)
P2 = ρ0E + P1 (18)
T2 = ρ1(P2 minus P1) + T1 (19)
We have enough pieces filled in to permit you to calculate theimpact on future climate of particular sorts of current consumptioneg burning a tank of propane on your bbq Wersquoll next start
Conclusion
Conclusion II
thinking about the effect of climate change on production γthough wersquoll make an aside to talk about measurement error first
Conclusion
Conclusion III
Each ppm of atmospheric CO2 corresponds to about 212 Gt C
and 778 Gt of CO2 Pay attention to the units people use
Not all gases are equal in their green house potential CO2 ismost common and most important but other gases are moreimportant per unit of emissions
Over the past 50 years about 55 of each emitted Gt of C
has stayed in the atmosphere The rest has been absorbed byland or oceans Thus it takes about 38 Gt C per 1ppm ofatmospheric CO2
Conclusion
Conclusion IV
Emissions are about 13Gt C for 2013 The rate at whichatmospheric CO2 is increasing has risen from about 1ppmyr1960s to 2ppm for 2000rsquos Since there is lots of fuel weshould expect atmospheric CO2 to continue to increase and atan increasing rate lsquobusiness as usual scenarios call foratmospheric CO2e gt 800 within 100 years
Not all countries are the same They are responsible fordifferent shares have different per capita emissions useemission more or less efficiently and are responsible fordifferent shares of historical emissions These factors are veryimportant obstacles to international agreements and alsosuggest the need for a richer model
Conclusion
Conclusion V
Steady state CO2 emissions are probably very small Sternsuggests less than 13 of current Our calculations suggest(1-055)=45
Emissions
CO2e 1970-2010
IPCC 2013 WG3 fig TS1
Right panel gives confidence bounds for 2010 49Gt CO2e in 2010
Emissions
CO2 by purpose and country income 1750-2010
IPCC 2013 WG3 fig TS2
Emissions
Hansenrsquos version of the same thing
Flow StockHansen 2009 fig 27
Contributions to stock and flow are very different At thenegotiating table developing countries want the right to emit sinceeveryone else had their turn
Emissions
2010 CO2e by purpose
IPCC 2013 WG3 fig TS3
Emissions
2010 CO2e by purpose and country income
IPCC 2013 WG3 fig TS3
Emissions
US 1990-2017 CO2e
ES-4 Inventory of US Greenhouse Gas Emissions and Sinks 1990ndash2017
ES2 Recent Trends in US Greenhouse Gas Emissions and Sinks
In 2017 total gross US greenhouse gas emissions were 64567 MMT or million metric tons of carbon dioxide (CO2) Eq11 Total US emissions have increased by 13 percent from 1990 to 2017 and emissions decreased from 2016 to 2017 by 05 percent (355 MMT CO2 Eq) The decrease in total greenhouse gas emissions between 2016 and 2017 was driven in part by a decrease in CO2 emissions from fossil fuel combustion The decrease in CO2 emissions from fossil fuel combustion was a result of multiple factors including a continued shift from coal to natural gas and increased use of renewable energy in the electric power sector and milder weather that contributed to less overall electricity use
Relative to 1990 the baseline for this Inventory gross emissions in 2017 are higher by 13 percent down from a high of 157 percent above 1990 levels in 2007 Overall net emissions in 2017 were 130 percent below 2005 levels as shown in Table ES-2 Figure ES-1 through Figure ES-3 illustrate the overall trends in total US emissions by gas annual changes and absolute change since 1990 and Table ES-2 provides a detailed summary of gross US greenhouse gas emissions and sinks for 1990 through 2017 Note unless otherwise stated all tables and figures provide total gross emissions and exclude the greenhouse gas fluxes from the Land Use Land-Use Change and Forestry (LULUCF) sector (see Section ES3 Overview of Sector Emissions and Trends)
Figure ES-1 Gross US Greenhouse Gas Emissions by Gas (MMT CO2 Eq)
11 The gross emissions total presented in this report for the United States excludes emissions and removals from Land Use Land-Use Change and Forestry (LULUCF) The net emissions total presented in this report for the United States includes emissions and removals from LULUCF
httpswwwepagovsitesproductionfiles2019-04documentsus-ghg-inventory-2019-main-textpdf September 2019
This reflects fracking recession technical progress off-shoring ofmanufacturing Emissions are likely up since 2017
Emissions
Emissions per person
Itrsquos also interesting to look at the country by country breakdown interms of emissions per capita
IPCC 2007 Mitigation fig SPM3a
As of 2012 US had 454 tons C person and for India this numberwas 046 China was 18(httpcdiacornlgovtrendsemistop2011cap)
Emissions
The problem of stabilizing atmospheric CO2Emissions are about 13Gt C per year
The ocean and biosphere absorb about 45 of emissions (sofar)
This means the ocean and biosphere absorb 13 times 045 asymp 6GtC per year
As a rough guess this means that reducing emissions to 6GtC per year will stabilize atmospheric CO2 (but not climate)
This involves a 55 decrease For an average American thismeans this means reducing emissions from 45 tons per yearto about 20 if US share of total emissions stays constant Ifemissions are allocated equally to each of the worldrsquos 74bpeople then each of us gets 6Gt C 74b people or about 08ton This is an 82 decrease for the average American It isalso about the twice the level of the average Indian and halfthat of the average Chinese
Emissions
Summary
2013 emissions of CO2e were about 49Gt Of this 35Gt wasCO2 and of this about 30Gt from fossil fuels and 5Gt fromland use change and agriculture This is E in our model
Emission are growing rapidly about 2year between 2000and 2010 1970 CO2e was 30Gt
2010 CO2e 14 transport 18 buildings 21 industry 24AFOLU We could use this to calculate refinements of ρ5
The countries responsible for most of the stock are not thecountries responsible for most of the flow
Per capita emissions vary by a factor of about 10 between richand poor countries
There has been a decline in US emissions since 2008 due tofracking recession technical progress off shoring
Peak oil
Will we run out of fossil fuel INot soon enough to matter
0
200
400
600
800
Estimated Reserves
Emissions to Date
Gig
aton
s C
arbo
n
Oil Gas Coal Land Use
EIA
IPCCEIA
IPCC
100
200
300
Em
itted
CO
2 (p
pm)
0
200
400
600
800
We have oceans of coal and lots of oil and these figures predateUS fracking
Peak oil
Will we run out of fossil fuel II
Conclusion
Conclusion I
Here is where we stand with our model
maxIM
u(c1 c2) (14)
st W = c1 + I + M (15)
c2 = (1 + r)I minus γ(T2 minus T1)I (16)
E = (1 minus ρ4MW
)(ρ5(c1 + I)) (17)
P2 = ρ0E + P1 (18)
T2 = ρ1(P2 minus P1) + T1 (19)
We have enough pieces filled in to permit you to calculate theimpact on future climate of particular sorts of current consumptioneg burning a tank of propane on your bbq Wersquoll next start
Conclusion
Conclusion II
thinking about the effect of climate change on production γthough wersquoll make an aside to talk about measurement error first
Conclusion
Conclusion III
Each ppm of atmospheric CO2 corresponds to about 212 Gt C
and 778 Gt of CO2 Pay attention to the units people use
Not all gases are equal in their green house potential CO2 ismost common and most important but other gases are moreimportant per unit of emissions
Over the past 50 years about 55 of each emitted Gt of C
has stayed in the atmosphere The rest has been absorbed byland or oceans Thus it takes about 38 Gt C per 1ppm ofatmospheric CO2
Conclusion
Conclusion IV
Emissions are about 13Gt C for 2013 The rate at whichatmospheric CO2 is increasing has risen from about 1ppmyr1960s to 2ppm for 2000rsquos Since there is lots of fuel weshould expect atmospheric CO2 to continue to increase and atan increasing rate lsquobusiness as usual scenarios call foratmospheric CO2e gt 800 within 100 years
Not all countries are the same They are responsible fordifferent shares have different per capita emissions useemission more or less efficiently and are responsible fordifferent shares of historical emissions These factors are veryimportant obstacles to international agreements and alsosuggest the need for a richer model
Conclusion
Conclusion V
Steady state CO2 emissions are probably very small Sternsuggests less than 13 of current Our calculations suggest(1-055)=45
Emissions
CO2 by purpose and country income 1750-2010
IPCC 2013 WG3 fig TS2
Emissions
Hansenrsquos version of the same thing
Flow StockHansen 2009 fig 27
Contributions to stock and flow are very different At thenegotiating table developing countries want the right to emit sinceeveryone else had their turn
Emissions
2010 CO2e by purpose
IPCC 2013 WG3 fig TS3
Emissions
2010 CO2e by purpose and country income
IPCC 2013 WG3 fig TS3
Emissions
US 1990-2017 CO2e
ES-4 Inventory of US Greenhouse Gas Emissions and Sinks 1990ndash2017
ES2 Recent Trends in US Greenhouse Gas Emissions and Sinks
In 2017 total gross US greenhouse gas emissions were 64567 MMT or million metric tons of carbon dioxide (CO2) Eq11 Total US emissions have increased by 13 percent from 1990 to 2017 and emissions decreased from 2016 to 2017 by 05 percent (355 MMT CO2 Eq) The decrease in total greenhouse gas emissions between 2016 and 2017 was driven in part by a decrease in CO2 emissions from fossil fuel combustion The decrease in CO2 emissions from fossil fuel combustion was a result of multiple factors including a continued shift from coal to natural gas and increased use of renewable energy in the electric power sector and milder weather that contributed to less overall electricity use
Relative to 1990 the baseline for this Inventory gross emissions in 2017 are higher by 13 percent down from a high of 157 percent above 1990 levels in 2007 Overall net emissions in 2017 were 130 percent below 2005 levels as shown in Table ES-2 Figure ES-1 through Figure ES-3 illustrate the overall trends in total US emissions by gas annual changes and absolute change since 1990 and Table ES-2 provides a detailed summary of gross US greenhouse gas emissions and sinks for 1990 through 2017 Note unless otherwise stated all tables and figures provide total gross emissions and exclude the greenhouse gas fluxes from the Land Use Land-Use Change and Forestry (LULUCF) sector (see Section ES3 Overview of Sector Emissions and Trends)
Figure ES-1 Gross US Greenhouse Gas Emissions by Gas (MMT CO2 Eq)
11 The gross emissions total presented in this report for the United States excludes emissions and removals from Land Use Land-Use Change and Forestry (LULUCF) The net emissions total presented in this report for the United States includes emissions and removals from LULUCF
httpswwwepagovsitesproductionfiles2019-04documentsus-ghg-inventory-2019-main-textpdf September 2019
This reflects fracking recession technical progress off-shoring ofmanufacturing Emissions are likely up since 2017
Emissions
Emissions per person
Itrsquos also interesting to look at the country by country breakdown interms of emissions per capita
IPCC 2007 Mitigation fig SPM3a
As of 2012 US had 454 tons C person and for India this numberwas 046 China was 18(httpcdiacornlgovtrendsemistop2011cap)
Emissions
The problem of stabilizing atmospheric CO2Emissions are about 13Gt C per year
The ocean and biosphere absorb about 45 of emissions (sofar)
This means the ocean and biosphere absorb 13 times 045 asymp 6GtC per year
As a rough guess this means that reducing emissions to 6GtC per year will stabilize atmospheric CO2 (but not climate)
This involves a 55 decrease For an average American thismeans this means reducing emissions from 45 tons per yearto about 20 if US share of total emissions stays constant Ifemissions are allocated equally to each of the worldrsquos 74bpeople then each of us gets 6Gt C 74b people or about 08ton This is an 82 decrease for the average American It isalso about the twice the level of the average Indian and halfthat of the average Chinese
Emissions
Summary
2013 emissions of CO2e were about 49Gt Of this 35Gt wasCO2 and of this about 30Gt from fossil fuels and 5Gt fromland use change and agriculture This is E in our model
Emission are growing rapidly about 2year between 2000and 2010 1970 CO2e was 30Gt
2010 CO2e 14 transport 18 buildings 21 industry 24AFOLU We could use this to calculate refinements of ρ5
The countries responsible for most of the stock are not thecountries responsible for most of the flow
Per capita emissions vary by a factor of about 10 between richand poor countries
There has been a decline in US emissions since 2008 due tofracking recession technical progress off shoring
Peak oil
Will we run out of fossil fuel INot soon enough to matter
0
200
400
600
800
Estimated Reserves
Emissions to Date
Gig
aton
s C
arbo
n
Oil Gas Coal Land Use
EIA
IPCCEIA
IPCC
100
200
300
Em
itted
CO
2 (p
pm)
0
200
400
600
800
We have oceans of coal and lots of oil and these figures predateUS fracking
Peak oil
Will we run out of fossil fuel II
Conclusion
Conclusion I
Here is where we stand with our model
maxIM
u(c1 c2) (14)
st W = c1 + I + M (15)
c2 = (1 + r)I minus γ(T2 minus T1)I (16)
E = (1 minus ρ4MW
)(ρ5(c1 + I)) (17)
P2 = ρ0E + P1 (18)
T2 = ρ1(P2 minus P1) + T1 (19)
We have enough pieces filled in to permit you to calculate theimpact on future climate of particular sorts of current consumptioneg burning a tank of propane on your bbq Wersquoll next start
Conclusion
Conclusion II
thinking about the effect of climate change on production γthough wersquoll make an aside to talk about measurement error first
Conclusion
Conclusion III
Each ppm of atmospheric CO2 corresponds to about 212 Gt C
and 778 Gt of CO2 Pay attention to the units people use
Not all gases are equal in their green house potential CO2 ismost common and most important but other gases are moreimportant per unit of emissions
Over the past 50 years about 55 of each emitted Gt of C
has stayed in the atmosphere The rest has been absorbed byland or oceans Thus it takes about 38 Gt C per 1ppm ofatmospheric CO2
Conclusion
Conclusion IV
Emissions are about 13Gt C for 2013 The rate at whichatmospheric CO2 is increasing has risen from about 1ppmyr1960s to 2ppm for 2000rsquos Since there is lots of fuel weshould expect atmospheric CO2 to continue to increase and atan increasing rate lsquobusiness as usual scenarios call foratmospheric CO2e gt 800 within 100 years
Not all countries are the same They are responsible fordifferent shares have different per capita emissions useemission more or less efficiently and are responsible fordifferent shares of historical emissions These factors are veryimportant obstacles to international agreements and alsosuggest the need for a richer model
Conclusion
Conclusion V
Steady state CO2 emissions are probably very small Sternsuggests less than 13 of current Our calculations suggest(1-055)=45
Emissions
Hansenrsquos version of the same thing
Flow StockHansen 2009 fig 27
Contributions to stock and flow are very different At thenegotiating table developing countries want the right to emit sinceeveryone else had their turn
Emissions
2010 CO2e by purpose
IPCC 2013 WG3 fig TS3
Emissions
2010 CO2e by purpose and country income
IPCC 2013 WG3 fig TS3
Emissions
US 1990-2017 CO2e
ES-4 Inventory of US Greenhouse Gas Emissions and Sinks 1990ndash2017
ES2 Recent Trends in US Greenhouse Gas Emissions and Sinks
In 2017 total gross US greenhouse gas emissions were 64567 MMT or million metric tons of carbon dioxide (CO2) Eq11 Total US emissions have increased by 13 percent from 1990 to 2017 and emissions decreased from 2016 to 2017 by 05 percent (355 MMT CO2 Eq) The decrease in total greenhouse gas emissions between 2016 and 2017 was driven in part by a decrease in CO2 emissions from fossil fuel combustion The decrease in CO2 emissions from fossil fuel combustion was a result of multiple factors including a continued shift from coal to natural gas and increased use of renewable energy in the electric power sector and milder weather that contributed to less overall electricity use
Relative to 1990 the baseline for this Inventory gross emissions in 2017 are higher by 13 percent down from a high of 157 percent above 1990 levels in 2007 Overall net emissions in 2017 were 130 percent below 2005 levels as shown in Table ES-2 Figure ES-1 through Figure ES-3 illustrate the overall trends in total US emissions by gas annual changes and absolute change since 1990 and Table ES-2 provides a detailed summary of gross US greenhouse gas emissions and sinks for 1990 through 2017 Note unless otherwise stated all tables and figures provide total gross emissions and exclude the greenhouse gas fluxes from the Land Use Land-Use Change and Forestry (LULUCF) sector (see Section ES3 Overview of Sector Emissions and Trends)
Figure ES-1 Gross US Greenhouse Gas Emissions by Gas (MMT CO2 Eq)
11 The gross emissions total presented in this report for the United States excludes emissions and removals from Land Use Land-Use Change and Forestry (LULUCF) The net emissions total presented in this report for the United States includes emissions and removals from LULUCF
httpswwwepagovsitesproductionfiles2019-04documentsus-ghg-inventory-2019-main-textpdf September 2019
This reflects fracking recession technical progress off-shoring ofmanufacturing Emissions are likely up since 2017
Emissions
Emissions per person
Itrsquos also interesting to look at the country by country breakdown interms of emissions per capita
IPCC 2007 Mitigation fig SPM3a
As of 2012 US had 454 tons C person and for India this numberwas 046 China was 18(httpcdiacornlgovtrendsemistop2011cap)
Emissions
The problem of stabilizing atmospheric CO2Emissions are about 13Gt C per year
The ocean and biosphere absorb about 45 of emissions (sofar)
This means the ocean and biosphere absorb 13 times 045 asymp 6GtC per year
As a rough guess this means that reducing emissions to 6GtC per year will stabilize atmospheric CO2 (but not climate)
This involves a 55 decrease For an average American thismeans this means reducing emissions from 45 tons per yearto about 20 if US share of total emissions stays constant Ifemissions are allocated equally to each of the worldrsquos 74bpeople then each of us gets 6Gt C 74b people or about 08ton This is an 82 decrease for the average American It isalso about the twice the level of the average Indian and halfthat of the average Chinese
Emissions
Summary
2013 emissions of CO2e were about 49Gt Of this 35Gt wasCO2 and of this about 30Gt from fossil fuels and 5Gt fromland use change and agriculture This is E in our model
Emission are growing rapidly about 2year between 2000and 2010 1970 CO2e was 30Gt
2010 CO2e 14 transport 18 buildings 21 industry 24AFOLU We could use this to calculate refinements of ρ5
The countries responsible for most of the stock are not thecountries responsible for most of the flow
Per capita emissions vary by a factor of about 10 between richand poor countries
There has been a decline in US emissions since 2008 due tofracking recession technical progress off shoring
Peak oil
Will we run out of fossil fuel INot soon enough to matter
0
200
400
600
800
Estimated Reserves
Emissions to Date
Gig
aton
s C
arbo
n
Oil Gas Coal Land Use
EIA
IPCCEIA
IPCC
100
200
300
Em
itted
CO
2 (p
pm)
0
200
400
600
800
We have oceans of coal and lots of oil and these figures predateUS fracking
Peak oil
Will we run out of fossil fuel II
Conclusion
Conclusion I
Here is where we stand with our model
maxIM
u(c1 c2) (14)
st W = c1 + I + M (15)
c2 = (1 + r)I minus γ(T2 minus T1)I (16)
E = (1 minus ρ4MW
)(ρ5(c1 + I)) (17)
P2 = ρ0E + P1 (18)
T2 = ρ1(P2 minus P1) + T1 (19)
We have enough pieces filled in to permit you to calculate theimpact on future climate of particular sorts of current consumptioneg burning a tank of propane on your bbq Wersquoll next start
Conclusion
Conclusion II
thinking about the effect of climate change on production γthough wersquoll make an aside to talk about measurement error first
Conclusion
Conclusion III
Each ppm of atmospheric CO2 corresponds to about 212 Gt C
and 778 Gt of CO2 Pay attention to the units people use
Not all gases are equal in their green house potential CO2 ismost common and most important but other gases are moreimportant per unit of emissions
Over the past 50 years about 55 of each emitted Gt of C
has stayed in the atmosphere The rest has been absorbed byland or oceans Thus it takes about 38 Gt C per 1ppm ofatmospheric CO2
Conclusion
Conclusion IV
Emissions are about 13Gt C for 2013 The rate at whichatmospheric CO2 is increasing has risen from about 1ppmyr1960s to 2ppm for 2000rsquos Since there is lots of fuel weshould expect atmospheric CO2 to continue to increase and atan increasing rate lsquobusiness as usual scenarios call foratmospheric CO2e gt 800 within 100 years
Not all countries are the same They are responsible fordifferent shares have different per capita emissions useemission more or less efficiently and are responsible fordifferent shares of historical emissions These factors are veryimportant obstacles to international agreements and alsosuggest the need for a richer model
Conclusion
Conclusion V
Steady state CO2 emissions are probably very small Sternsuggests less than 13 of current Our calculations suggest(1-055)=45
Emissions
2010 CO2e by purpose
IPCC 2013 WG3 fig TS3
Emissions
2010 CO2e by purpose and country income
IPCC 2013 WG3 fig TS3
Emissions
US 1990-2017 CO2e
ES-4 Inventory of US Greenhouse Gas Emissions and Sinks 1990ndash2017
ES2 Recent Trends in US Greenhouse Gas Emissions and Sinks
In 2017 total gross US greenhouse gas emissions were 64567 MMT or million metric tons of carbon dioxide (CO2) Eq11 Total US emissions have increased by 13 percent from 1990 to 2017 and emissions decreased from 2016 to 2017 by 05 percent (355 MMT CO2 Eq) The decrease in total greenhouse gas emissions between 2016 and 2017 was driven in part by a decrease in CO2 emissions from fossil fuel combustion The decrease in CO2 emissions from fossil fuel combustion was a result of multiple factors including a continued shift from coal to natural gas and increased use of renewable energy in the electric power sector and milder weather that contributed to less overall electricity use
Relative to 1990 the baseline for this Inventory gross emissions in 2017 are higher by 13 percent down from a high of 157 percent above 1990 levels in 2007 Overall net emissions in 2017 were 130 percent below 2005 levels as shown in Table ES-2 Figure ES-1 through Figure ES-3 illustrate the overall trends in total US emissions by gas annual changes and absolute change since 1990 and Table ES-2 provides a detailed summary of gross US greenhouse gas emissions and sinks for 1990 through 2017 Note unless otherwise stated all tables and figures provide total gross emissions and exclude the greenhouse gas fluxes from the Land Use Land-Use Change and Forestry (LULUCF) sector (see Section ES3 Overview of Sector Emissions and Trends)
Figure ES-1 Gross US Greenhouse Gas Emissions by Gas (MMT CO2 Eq)
11 The gross emissions total presented in this report for the United States excludes emissions and removals from Land Use Land-Use Change and Forestry (LULUCF) The net emissions total presented in this report for the United States includes emissions and removals from LULUCF
httpswwwepagovsitesproductionfiles2019-04documentsus-ghg-inventory-2019-main-textpdf September 2019
This reflects fracking recession technical progress off-shoring ofmanufacturing Emissions are likely up since 2017
Emissions
Emissions per person
Itrsquos also interesting to look at the country by country breakdown interms of emissions per capita
IPCC 2007 Mitigation fig SPM3a
As of 2012 US had 454 tons C person and for India this numberwas 046 China was 18(httpcdiacornlgovtrendsemistop2011cap)
Emissions
The problem of stabilizing atmospheric CO2Emissions are about 13Gt C per year
The ocean and biosphere absorb about 45 of emissions (sofar)
This means the ocean and biosphere absorb 13 times 045 asymp 6GtC per year
As a rough guess this means that reducing emissions to 6GtC per year will stabilize atmospheric CO2 (but not climate)
This involves a 55 decrease For an average American thismeans this means reducing emissions from 45 tons per yearto about 20 if US share of total emissions stays constant Ifemissions are allocated equally to each of the worldrsquos 74bpeople then each of us gets 6Gt C 74b people or about 08ton This is an 82 decrease for the average American It isalso about the twice the level of the average Indian and halfthat of the average Chinese
Emissions
Summary
2013 emissions of CO2e were about 49Gt Of this 35Gt wasCO2 and of this about 30Gt from fossil fuels and 5Gt fromland use change and agriculture This is E in our model
Emission are growing rapidly about 2year between 2000and 2010 1970 CO2e was 30Gt
2010 CO2e 14 transport 18 buildings 21 industry 24AFOLU We could use this to calculate refinements of ρ5
The countries responsible for most of the stock are not thecountries responsible for most of the flow
Per capita emissions vary by a factor of about 10 between richand poor countries
There has been a decline in US emissions since 2008 due tofracking recession technical progress off shoring
Peak oil
Will we run out of fossil fuel INot soon enough to matter
0
200
400
600
800
Estimated Reserves
Emissions to Date
Gig
aton
s C
arbo
n
Oil Gas Coal Land Use
EIA
IPCCEIA
IPCC
100
200
300
Em
itted
CO
2 (p
pm)
0
200
400
600
800
We have oceans of coal and lots of oil and these figures predateUS fracking
Peak oil
Will we run out of fossil fuel II
Conclusion
Conclusion I
Here is where we stand with our model
maxIM
u(c1 c2) (14)
st W = c1 + I + M (15)
c2 = (1 + r)I minus γ(T2 minus T1)I (16)
E = (1 minus ρ4MW
)(ρ5(c1 + I)) (17)
P2 = ρ0E + P1 (18)
T2 = ρ1(P2 minus P1) + T1 (19)
We have enough pieces filled in to permit you to calculate theimpact on future climate of particular sorts of current consumptioneg burning a tank of propane on your bbq Wersquoll next start
Conclusion
Conclusion II
thinking about the effect of climate change on production γthough wersquoll make an aside to talk about measurement error first
Conclusion
Conclusion III
Each ppm of atmospheric CO2 corresponds to about 212 Gt C
and 778 Gt of CO2 Pay attention to the units people use
Not all gases are equal in their green house potential CO2 ismost common and most important but other gases are moreimportant per unit of emissions
Over the past 50 years about 55 of each emitted Gt of C
has stayed in the atmosphere The rest has been absorbed byland or oceans Thus it takes about 38 Gt C per 1ppm ofatmospheric CO2
Conclusion
Conclusion IV
Emissions are about 13Gt C for 2013 The rate at whichatmospheric CO2 is increasing has risen from about 1ppmyr1960s to 2ppm for 2000rsquos Since there is lots of fuel weshould expect atmospheric CO2 to continue to increase and atan increasing rate lsquobusiness as usual scenarios call foratmospheric CO2e gt 800 within 100 years
Not all countries are the same They are responsible fordifferent shares have different per capita emissions useemission more or less efficiently and are responsible fordifferent shares of historical emissions These factors are veryimportant obstacles to international agreements and alsosuggest the need for a richer model
Conclusion
Conclusion V
Steady state CO2 emissions are probably very small Sternsuggests less than 13 of current Our calculations suggest(1-055)=45
Emissions
2010 CO2e by purpose and country income
IPCC 2013 WG3 fig TS3
Emissions
US 1990-2017 CO2e
ES-4 Inventory of US Greenhouse Gas Emissions and Sinks 1990ndash2017
ES2 Recent Trends in US Greenhouse Gas Emissions and Sinks
In 2017 total gross US greenhouse gas emissions were 64567 MMT or million metric tons of carbon dioxide (CO2) Eq11 Total US emissions have increased by 13 percent from 1990 to 2017 and emissions decreased from 2016 to 2017 by 05 percent (355 MMT CO2 Eq) The decrease in total greenhouse gas emissions between 2016 and 2017 was driven in part by a decrease in CO2 emissions from fossil fuel combustion The decrease in CO2 emissions from fossil fuel combustion was a result of multiple factors including a continued shift from coal to natural gas and increased use of renewable energy in the electric power sector and milder weather that contributed to less overall electricity use
Relative to 1990 the baseline for this Inventory gross emissions in 2017 are higher by 13 percent down from a high of 157 percent above 1990 levels in 2007 Overall net emissions in 2017 were 130 percent below 2005 levels as shown in Table ES-2 Figure ES-1 through Figure ES-3 illustrate the overall trends in total US emissions by gas annual changes and absolute change since 1990 and Table ES-2 provides a detailed summary of gross US greenhouse gas emissions and sinks for 1990 through 2017 Note unless otherwise stated all tables and figures provide total gross emissions and exclude the greenhouse gas fluxes from the Land Use Land-Use Change and Forestry (LULUCF) sector (see Section ES3 Overview of Sector Emissions and Trends)
Figure ES-1 Gross US Greenhouse Gas Emissions by Gas (MMT CO2 Eq)
11 The gross emissions total presented in this report for the United States excludes emissions and removals from Land Use Land-Use Change and Forestry (LULUCF) The net emissions total presented in this report for the United States includes emissions and removals from LULUCF
httpswwwepagovsitesproductionfiles2019-04documentsus-ghg-inventory-2019-main-textpdf September 2019
This reflects fracking recession technical progress off-shoring ofmanufacturing Emissions are likely up since 2017
Emissions
Emissions per person
Itrsquos also interesting to look at the country by country breakdown interms of emissions per capita
IPCC 2007 Mitigation fig SPM3a
As of 2012 US had 454 tons C person and for India this numberwas 046 China was 18(httpcdiacornlgovtrendsemistop2011cap)
Emissions
The problem of stabilizing atmospheric CO2Emissions are about 13Gt C per year
The ocean and biosphere absorb about 45 of emissions (sofar)
This means the ocean and biosphere absorb 13 times 045 asymp 6GtC per year
As a rough guess this means that reducing emissions to 6GtC per year will stabilize atmospheric CO2 (but not climate)
This involves a 55 decrease For an average American thismeans this means reducing emissions from 45 tons per yearto about 20 if US share of total emissions stays constant Ifemissions are allocated equally to each of the worldrsquos 74bpeople then each of us gets 6Gt C 74b people or about 08ton This is an 82 decrease for the average American It isalso about the twice the level of the average Indian and halfthat of the average Chinese
Emissions
Summary
2013 emissions of CO2e were about 49Gt Of this 35Gt wasCO2 and of this about 30Gt from fossil fuels and 5Gt fromland use change and agriculture This is E in our model
Emission are growing rapidly about 2year between 2000and 2010 1970 CO2e was 30Gt
2010 CO2e 14 transport 18 buildings 21 industry 24AFOLU We could use this to calculate refinements of ρ5
The countries responsible for most of the stock are not thecountries responsible for most of the flow
Per capita emissions vary by a factor of about 10 between richand poor countries
There has been a decline in US emissions since 2008 due tofracking recession technical progress off shoring
Peak oil
Will we run out of fossil fuel INot soon enough to matter
0
200
400
600
800
Estimated Reserves
Emissions to Date
Gig
aton
s C
arbo
n
Oil Gas Coal Land Use
EIA
IPCCEIA
IPCC
100
200
300
Em
itted
CO
2 (p
pm)
0
200
400
600
800
We have oceans of coal and lots of oil and these figures predateUS fracking
Peak oil
Will we run out of fossil fuel II
Conclusion
Conclusion I
Here is where we stand with our model
maxIM
u(c1 c2) (14)
st W = c1 + I + M (15)
c2 = (1 + r)I minus γ(T2 minus T1)I (16)
E = (1 minus ρ4MW
)(ρ5(c1 + I)) (17)
P2 = ρ0E + P1 (18)
T2 = ρ1(P2 minus P1) + T1 (19)
We have enough pieces filled in to permit you to calculate theimpact on future climate of particular sorts of current consumptioneg burning a tank of propane on your bbq Wersquoll next start
Conclusion
Conclusion II
thinking about the effect of climate change on production γthough wersquoll make an aside to talk about measurement error first
Conclusion
Conclusion III
Each ppm of atmospheric CO2 corresponds to about 212 Gt C
and 778 Gt of CO2 Pay attention to the units people use
Not all gases are equal in their green house potential CO2 ismost common and most important but other gases are moreimportant per unit of emissions
Over the past 50 years about 55 of each emitted Gt of C
has stayed in the atmosphere The rest has been absorbed byland or oceans Thus it takes about 38 Gt C per 1ppm ofatmospheric CO2
Conclusion
Conclusion IV
Emissions are about 13Gt C for 2013 The rate at whichatmospheric CO2 is increasing has risen from about 1ppmyr1960s to 2ppm for 2000rsquos Since there is lots of fuel weshould expect atmospheric CO2 to continue to increase and atan increasing rate lsquobusiness as usual scenarios call foratmospheric CO2e gt 800 within 100 years
Not all countries are the same They are responsible fordifferent shares have different per capita emissions useemission more or less efficiently and are responsible fordifferent shares of historical emissions These factors are veryimportant obstacles to international agreements and alsosuggest the need for a richer model
Conclusion
Conclusion V
Steady state CO2 emissions are probably very small Sternsuggests less than 13 of current Our calculations suggest(1-055)=45
Emissions
US 1990-2017 CO2e
ES-4 Inventory of US Greenhouse Gas Emissions and Sinks 1990ndash2017
ES2 Recent Trends in US Greenhouse Gas Emissions and Sinks
In 2017 total gross US greenhouse gas emissions were 64567 MMT or million metric tons of carbon dioxide (CO2) Eq11 Total US emissions have increased by 13 percent from 1990 to 2017 and emissions decreased from 2016 to 2017 by 05 percent (355 MMT CO2 Eq) The decrease in total greenhouse gas emissions between 2016 and 2017 was driven in part by a decrease in CO2 emissions from fossil fuel combustion The decrease in CO2 emissions from fossil fuel combustion was a result of multiple factors including a continued shift from coal to natural gas and increased use of renewable energy in the electric power sector and milder weather that contributed to less overall electricity use
Relative to 1990 the baseline for this Inventory gross emissions in 2017 are higher by 13 percent down from a high of 157 percent above 1990 levels in 2007 Overall net emissions in 2017 were 130 percent below 2005 levels as shown in Table ES-2 Figure ES-1 through Figure ES-3 illustrate the overall trends in total US emissions by gas annual changes and absolute change since 1990 and Table ES-2 provides a detailed summary of gross US greenhouse gas emissions and sinks for 1990 through 2017 Note unless otherwise stated all tables and figures provide total gross emissions and exclude the greenhouse gas fluxes from the Land Use Land-Use Change and Forestry (LULUCF) sector (see Section ES3 Overview of Sector Emissions and Trends)
Figure ES-1 Gross US Greenhouse Gas Emissions by Gas (MMT CO2 Eq)
11 The gross emissions total presented in this report for the United States excludes emissions and removals from Land Use Land-Use Change and Forestry (LULUCF) The net emissions total presented in this report for the United States includes emissions and removals from LULUCF
httpswwwepagovsitesproductionfiles2019-04documentsus-ghg-inventory-2019-main-textpdf September 2019
This reflects fracking recession technical progress off-shoring ofmanufacturing Emissions are likely up since 2017
Emissions
Emissions per person
Itrsquos also interesting to look at the country by country breakdown interms of emissions per capita
IPCC 2007 Mitigation fig SPM3a
As of 2012 US had 454 tons C person and for India this numberwas 046 China was 18(httpcdiacornlgovtrendsemistop2011cap)
Emissions
The problem of stabilizing atmospheric CO2Emissions are about 13Gt C per year
The ocean and biosphere absorb about 45 of emissions (sofar)
This means the ocean and biosphere absorb 13 times 045 asymp 6GtC per year
As a rough guess this means that reducing emissions to 6GtC per year will stabilize atmospheric CO2 (but not climate)
This involves a 55 decrease For an average American thismeans this means reducing emissions from 45 tons per yearto about 20 if US share of total emissions stays constant Ifemissions are allocated equally to each of the worldrsquos 74bpeople then each of us gets 6Gt C 74b people or about 08ton This is an 82 decrease for the average American It isalso about the twice the level of the average Indian and halfthat of the average Chinese
Emissions
Summary
2013 emissions of CO2e were about 49Gt Of this 35Gt wasCO2 and of this about 30Gt from fossil fuels and 5Gt fromland use change and agriculture This is E in our model
Emission are growing rapidly about 2year between 2000and 2010 1970 CO2e was 30Gt
2010 CO2e 14 transport 18 buildings 21 industry 24AFOLU We could use this to calculate refinements of ρ5
The countries responsible for most of the stock are not thecountries responsible for most of the flow
Per capita emissions vary by a factor of about 10 between richand poor countries
There has been a decline in US emissions since 2008 due tofracking recession technical progress off shoring
Peak oil
Will we run out of fossil fuel INot soon enough to matter
0
200
400
600
800
Estimated Reserves
Emissions to Date
Gig
aton
s C
arbo
n
Oil Gas Coal Land Use
EIA
IPCCEIA
IPCC
100
200
300
Em
itted
CO
2 (p
pm)
0
200
400
600
800
We have oceans of coal and lots of oil and these figures predateUS fracking
Peak oil
Will we run out of fossil fuel II
Conclusion
Conclusion I
Here is where we stand with our model
maxIM
u(c1 c2) (14)
st W = c1 + I + M (15)
c2 = (1 + r)I minus γ(T2 minus T1)I (16)
E = (1 minus ρ4MW
)(ρ5(c1 + I)) (17)
P2 = ρ0E + P1 (18)
T2 = ρ1(P2 minus P1) + T1 (19)
We have enough pieces filled in to permit you to calculate theimpact on future climate of particular sorts of current consumptioneg burning a tank of propane on your bbq Wersquoll next start
Conclusion
Conclusion II
thinking about the effect of climate change on production γthough wersquoll make an aside to talk about measurement error first
Conclusion
Conclusion III
Each ppm of atmospheric CO2 corresponds to about 212 Gt C
and 778 Gt of CO2 Pay attention to the units people use
Not all gases are equal in their green house potential CO2 ismost common and most important but other gases are moreimportant per unit of emissions
Over the past 50 years about 55 of each emitted Gt of C
has stayed in the atmosphere The rest has been absorbed byland or oceans Thus it takes about 38 Gt C per 1ppm ofatmospheric CO2
Conclusion
Conclusion IV
Emissions are about 13Gt C for 2013 The rate at whichatmospheric CO2 is increasing has risen from about 1ppmyr1960s to 2ppm for 2000rsquos Since there is lots of fuel weshould expect atmospheric CO2 to continue to increase and atan increasing rate lsquobusiness as usual scenarios call foratmospheric CO2e gt 800 within 100 years
Not all countries are the same They are responsible fordifferent shares have different per capita emissions useemission more or less efficiently and are responsible fordifferent shares of historical emissions These factors are veryimportant obstacles to international agreements and alsosuggest the need for a richer model
Conclusion
Conclusion V
Steady state CO2 emissions are probably very small Sternsuggests less than 13 of current Our calculations suggest(1-055)=45
Emissions
Emissions per person
Itrsquos also interesting to look at the country by country breakdown interms of emissions per capita
IPCC 2007 Mitigation fig SPM3a
As of 2012 US had 454 tons C person and for India this numberwas 046 China was 18(httpcdiacornlgovtrendsemistop2011cap)
Emissions
The problem of stabilizing atmospheric CO2Emissions are about 13Gt C per year
The ocean and biosphere absorb about 45 of emissions (sofar)
This means the ocean and biosphere absorb 13 times 045 asymp 6GtC per year
As a rough guess this means that reducing emissions to 6GtC per year will stabilize atmospheric CO2 (but not climate)
This involves a 55 decrease For an average American thismeans this means reducing emissions from 45 tons per yearto about 20 if US share of total emissions stays constant Ifemissions are allocated equally to each of the worldrsquos 74bpeople then each of us gets 6Gt C 74b people or about 08ton This is an 82 decrease for the average American It isalso about the twice the level of the average Indian and halfthat of the average Chinese
Emissions
Summary
2013 emissions of CO2e were about 49Gt Of this 35Gt wasCO2 and of this about 30Gt from fossil fuels and 5Gt fromland use change and agriculture This is E in our model
Emission are growing rapidly about 2year between 2000and 2010 1970 CO2e was 30Gt
2010 CO2e 14 transport 18 buildings 21 industry 24AFOLU We could use this to calculate refinements of ρ5
The countries responsible for most of the stock are not thecountries responsible for most of the flow
Per capita emissions vary by a factor of about 10 between richand poor countries
There has been a decline in US emissions since 2008 due tofracking recession technical progress off shoring
Peak oil
Will we run out of fossil fuel INot soon enough to matter
0
200
400
600
800
Estimated Reserves
Emissions to Date
Gig
aton
s C
arbo
n
Oil Gas Coal Land Use
EIA
IPCCEIA
IPCC
100
200
300
Em
itted
CO
2 (p
pm)
0
200
400
600
800
We have oceans of coal and lots of oil and these figures predateUS fracking
Peak oil
Will we run out of fossil fuel II
Conclusion
Conclusion I
Here is where we stand with our model
maxIM
u(c1 c2) (14)
st W = c1 + I + M (15)
c2 = (1 + r)I minus γ(T2 minus T1)I (16)
E = (1 minus ρ4MW
)(ρ5(c1 + I)) (17)
P2 = ρ0E + P1 (18)
T2 = ρ1(P2 minus P1) + T1 (19)
We have enough pieces filled in to permit you to calculate theimpact on future climate of particular sorts of current consumptioneg burning a tank of propane on your bbq Wersquoll next start
Conclusion
Conclusion II
thinking about the effect of climate change on production γthough wersquoll make an aside to talk about measurement error first
Conclusion
Conclusion III
Each ppm of atmospheric CO2 corresponds to about 212 Gt C
and 778 Gt of CO2 Pay attention to the units people use
Not all gases are equal in their green house potential CO2 ismost common and most important but other gases are moreimportant per unit of emissions
Over the past 50 years about 55 of each emitted Gt of C
has stayed in the atmosphere The rest has been absorbed byland or oceans Thus it takes about 38 Gt C per 1ppm ofatmospheric CO2
Conclusion
Conclusion IV
Emissions are about 13Gt C for 2013 The rate at whichatmospheric CO2 is increasing has risen from about 1ppmyr1960s to 2ppm for 2000rsquos Since there is lots of fuel weshould expect atmospheric CO2 to continue to increase and atan increasing rate lsquobusiness as usual scenarios call foratmospheric CO2e gt 800 within 100 years
Not all countries are the same They are responsible fordifferent shares have different per capita emissions useemission more or less efficiently and are responsible fordifferent shares of historical emissions These factors are veryimportant obstacles to international agreements and alsosuggest the need for a richer model
Conclusion
Conclusion V
Steady state CO2 emissions are probably very small Sternsuggests less than 13 of current Our calculations suggest(1-055)=45
Emissions
The problem of stabilizing atmospheric CO2Emissions are about 13Gt C per year
The ocean and biosphere absorb about 45 of emissions (sofar)
This means the ocean and biosphere absorb 13 times 045 asymp 6GtC per year
As a rough guess this means that reducing emissions to 6GtC per year will stabilize atmospheric CO2 (but not climate)
This involves a 55 decrease For an average American thismeans this means reducing emissions from 45 tons per yearto about 20 if US share of total emissions stays constant Ifemissions are allocated equally to each of the worldrsquos 74bpeople then each of us gets 6Gt C 74b people or about 08ton This is an 82 decrease for the average American It isalso about the twice the level of the average Indian and halfthat of the average Chinese
Emissions
Summary
2013 emissions of CO2e were about 49Gt Of this 35Gt wasCO2 and of this about 30Gt from fossil fuels and 5Gt fromland use change and agriculture This is E in our model
Emission are growing rapidly about 2year between 2000and 2010 1970 CO2e was 30Gt
2010 CO2e 14 transport 18 buildings 21 industry 24AFOLU We could use this to calculate refinements of ρ5
The countries responsible for most of the stock are not thecountries responsible for most of the flow
Per capita emissions vary by a factor of about 10 between richand poor countries
There has been a decline in US emissions since 2008 due tofracking recession technical progress off shoring
Peak oil
Will we run out of fossil fuel INot soon enough to matter
0
200
400
600
800
Estimated Reserves
Emissions to Date
Gig
aton
s C
arbo
n
Oil Gas Coal Land Use
EIA
IPCCEIA
IPCC
100
200
300
Em
itted
CO
2 (p
pm)
0
200
400
600
800
We have oceans of coal and lots of oil and these figures predateUS fracking
Peak oil
Will we run out of fossil fuel II
Conclusion
Conclusion I
Here is where we stand with our model
maxIM
u(c1 c2) (14)
st W = c1 + I + M (15)
c2 = (1 + r)I minus γ(T2 minus T1)I (16)
E = (1 minus ρ4MW
)(ρ5(c1 + I)) (17)
P2 = ρ0E + P1 (18)
T2 = ρ1(P2 minus P1) + T1 (19)
We have enough pieces filled in to permit you to calculate theimpact on future climate of particular sorts of current consumptioneg burning a tank of propane on your bbq Wersquoll next start
Conclusion
Conclusion II
thinking about the effect of climate change on production γthough wersquoll make an aside to talk about measurement error first
Conclusion
Conclusion III
Each ppm of atmospheric CO2 corresponds to about 212 Gt C
and 778 Gt of CO2 Pay attention to the units people use
Not all gases are equal in their green house potential CO2 ismost common and most important but other gases are moreimportant per unit of emissions
Over the past 50 years about 55 of each emitted Gt of C
has stayed in the atmosphere The rest has been absorbed byland or oceans Thus it takes about 38 Gt C per 1ppm ofatmospheric CO2
Conclusion
Conclusion IV
Emissions are about 13Gt C for 2013 The rate at whichatmospheric CO2 is increasing has risen from about 1ppmyr1960s to 2ppm for 2000rsquos Since there is lots of fuel weshould expect atmospheric CO2 to continue to increase and atan increasing rate lsquobusiness as usual scenarios call foratmospheric CO2e gt 800 within 100 years
Not all countries are the same They are responsible fordifferent shares have different per capita emissions useemission more or less efficiently and are responsible fordifferent shares of historical emissions These factors are veryimportant obstacles to international agreements and alsosuggest the need for a richer model
Conclusion
Conclusion V
Steady state CO2 emissions are probably very small Sternsuggests less than 13 of current Our calculations suggest(1-055)=45
Emissions
Summary
2013 emissions of CO2e were about 49Gt Of this 35Gt wasCO2 and of this about 30Gt from fossil fuels and 5Gt fromland use change and agriculture This is E in our model
Emission are growing rapidly about 2year between 2000and 2010 1970 CO2e was 30Gt
2010 CO2e 14 transport 18 buildings 21 industry 24AFOLU We could use this to calculate refinements of ρ5
The countries responsible for most of the stock are not thecountries responsible for most of the flow
Per capita emissions vary by a factor of about 10 between richand poor countries
There has been a decline in US emissions since 2008 due tofracking recession technical progress off shoring
Peak oil
Will we run out of fossil fuel INot soon enough to matter
0
200
400
600
800
Estimated Reserves
Emissions to Date
Gig
aton
s C
arbo
n
Oil Gas Coal Land Use
EIA
IPCCEIA
IPCC
100
200
300
Em
itted
CO
2 (p
pm)
0
200
400
600
800
We have oceans of coal and lots of oil and these figures predateUS fracking
Peak oil
Will we run out of fossil fuel II
Conclusion
Conclusion I
Here is where we stand with our model
maxIM
u(c1 c2) (14)
st W = c1 + I + M (15)
c2 = (1 + r)I minus γ(T2 minus T1)I (16)
E = (1 minus ρ4MW
)(ρ5(c1 + I)) (17)
P2 = ρ0E + P1 (18)
T2 = ρ1(P2 minus P1) + T1 (19)
We have enough pieces filled in to permit you to calculate theimpact on future climate of particular sorts of current consumptioneg burning a tank of propane on your bbq Wersquoll next start
Conclusion
Conclusion II
thinking about the effect of climate change on production γthough wersquoll make an aside to talk about measurement error first
Conclusion
Conclusion III
Each ppm of atmospheric CO2 corresponds to about 212 Gt C
and 778 Gt of CO2 Pay attention to the units people use
Not all gases are equal in their green house potential CO2 ismost common and most important but other gases are moreimportant per unit of emissions
Over the past 50 years about 55 of each emitted Gt of C
has stayed in the atmosphere The rest has been absorbed byland or oceans Thus it takes about 38 Gt C per 1ppm ofatmospheric CO2
Conclusion
Conclusion IV
Emissions are about 13Gt C for 2013 The rate at whichatmospheric CO2 is increasing has risen from about 1ppmyr1960s to 2ppm for 2000rsquos Since there is lots of fuel weshould expect atmospheric CO2 to continue to increase and atan increasing rate lsquobusiness as usual scenarios call foratmospheric CO2e gt 800 within 100 years
Not all countries are the same They are responsible fordifferent shares have different per capita emissions useemission more or less efficiently and are responsible fordifferent shares of historical emissions These factors are veryimportant obstacles to international agreements and alsosuggest the need for a richer model
Conclusion
Conclusion V
Steady state CO2 emissions are probably very small Sternsuggests less than 13 of current Our calculations suggest(1-055)=45
Peak oil
Will we run out of fossil fuel INot soon enough to matter
0
200
400
600
800
Estimated Reserves
Emissions to Date
Gig
aton
s C
arbo
n
Oil Gas Coal Land Use
EIA
IPCCEIA
IPCC
100
200
300
Em
itted
CO
2 (p
pm)
0
200
400
600
800
We have oceans of coal and lots of oil and these figures predateUS fracking
Peak oil
Will we run out of fossil fuel II
Conclusion
Conclusion I
Here is where we stand with our model
maxIM
u(c1 c2) (14)
st W = c1 + I + M (15)
c2 = (1 + r)I minus γ(T2 minus T1)I (16)
E = (1 minus ρ4MW
)(ρ5(c1 + I)) (17)
P2 = ρ0E + P1 (18)
T2 = ρ1(P2 minus P1) + T1 (19)
We have enough pieces filled in to permit you to calculate theimpact on future climate of particular sorts of current consumptioneg burning a tank of propane on your bbq Wersquoll next start
Conclusion
Conclusion II
thinking about the effect of climate change on production γthough wersquoll make an aside to talk about measurement error first
Conclusion
Conclusion III
Each ppm of atmospheric CO2 corresponds to about 212 Gt C
and 778 Gt of CO2 Pay attention to the units people use
Not all gases are equal in their green house potential CO2 ismost common and most important but other gases are moreimportant per unit of emissions
Over the past 50 years about 55 of each emitted Gt of C
has stayed in the atmosphere The rest has been absorbed byland or oceans Thus it takes about 38 Gt C per 1ppm ofatmospheric CO2
Conclusion
Conclusion IV
Emissions are about 13Gt C for 2013 The rate at whichatmospheric CO2 is increasing has risen from about 1ppmyr1960s to 2ppm for 2000rsquos Since there is lots of fuel weshould expect atmospheric CO2 to continue to increase and atan increasing rate lsquobusiness as usual scenarios call foratmospheric CO2e gt 800 within 100 years
Not all countries are the same They are responsible fordifferent shares have different per capita emissions useemission more or less efficiently and are responsible fordifferent shares of historical emissions These factors are veryimportant obstacles to international agreements and alsosuggest the need for a richer model
Conclusion
Conclusion V
Steady state CO2 emissions are probably very small Sternsuggests less than 13 of current Our calculations suggest(1-055)=45
Peak oil
Will we run out of fossil fuel II
Conclusion
Conclusion I
Here is where we stand with our model
maxIM
u(c1 c2) (14)
st W = c1 + I + M (15)
c2 = (1 + r)I minus γ(T2 minus T1)I (16)
E = (1 minus ρ4MW
)(ρ5(c1 + I)) (17)
P2 = ρ0E + P1 (18)
T2 = ρ1(P2 minus P1) + T1 (19)
We have enough pieces filled in to permit you to calculate theimpact on future climate of particular sorts of current consumptioneg burning a tank of propane on your bbq Wersquoll next start
Conclusion
Conclusion II
thinking about the effect of climate change on production γthough wersquoll make an aside to talk about measurement error first
Conclusion
Conclusion III
Each ppm of atmospheric CO2 corresponds to about 212 Gt C
and 778 Gt of CO2 Pay attention to the units people use
Not all gases are equal in their green house potential CO2 ismost common and most important but other gases are moreimportant per unit of emissions
Over the past 50 years about 55 of each emitted Gt of C
has stayed in the atmosphere The rest has been absorbed byland or oceans Thus it takes about 38 Gt C per 1ppm ofatmospheric CO2
Conclusion
Conclusion IV
Emissions are about 13Gt C for 2013 The rate at whichatmospheric CO2 is increasing has risen from about 1ppmyr1960s to 2ppm for 2000rsquos Since there is lots of fuel weshould expect atmospheric CO2 to continue to increase and atan increasing rate lsquobusiness as usual scenarios call foratmospheric CO2e gt 800 within 100 years
Not all countries are the same They are responsible fordifferent shares have different per capita emissions useemission more or less efficiently and are responsible fordifferent shares of historical emissions These factors are veryimportant obstacles to international agreements and alsosuggest the need for a richer model
Conclusion
Conclusion V
Steady state CO2 emissions are probably very small Sternsuggests less than 13 of current Our calculations suggest(1-055)=45
Conclusion
Conclusion I
Here is where we stand with our model
maxIM
u(c1 c2) (14)
st W = c1 + I + M (15)
c2 = (1 + r)I minus γ(T2 minus T1)I (16)
E = (1 minus ρ4MW
)(ρ5(c1 + I)) (17)
P2 = ρ0E + P1 (18)
T2 = ρ1(P2 minus P1) + T1 (19)
We have enough pieces filled in to permit you to calculate theimpact on future climate of particular sorts of current consumptioneg burning a tank of propane on your bbq Wersquoll next start
Conclusion
Conclusion II
thinking about the effect of climate change on production γthough wersquoll make an aside to talk about measurement error first
Conclusion
Conclusion III
Each ppm of atmospheric CO2 corresponds to about 212 Gt C
and 778 Gt of CO2 Pay attention to the units people use
Not all gases are equal in their green house potential CO2 ismost common and most important but other gases are moreimportant per unit of emissions
Over the past 50 years about 55 of each emitted Gt of C
has stayed in the atmosphere The rest has been absorbed byland or oceans Thus it takes about 38 Gt C per 1ppm ofatmospheric CO2
Conclusion
Conclusion IV
Emissions are about 13Gt C for 2013 The rate at whichatmospheric CO2 is increasing has risen from about 1ppmyr1960s to 2ppm for 2000rsquos Since there is lots of fuel weshould expect atmospheric CO2 to continue to increase and atan increasing rate lsquobusiness as usual scenarios call foratmospheric CO2e gt 800 within 100 years
Not all countries are the same They are responsible fordifferent shares have different per capita emissions useemission more or less efficiently and are responsible fordifferent shares of historical emissions These factors are veryimportant obstacles to international agreements and alsosuggest the need for a richer model
Conclusion
Conclusion V
Steady state CO2 emissions are probably very small Sternsuggests less than 13 of current Our calculations suggest(1-055)=45
Conclusion
Conclusion II
thinking about the effect of climate change on production γthough wersquoll make an aside to talk about measurement error first
Conclusion
Conclusion III
Each ppm of atmospheric CO2 corresponds to about 212 Gt C
and 778 Gt of CO2 Pay attention to the units people use
Not all gases are equal in their green house potential CO2 ismost common and most important but other gases are moreimportant per unit of emissions
Over the past 50 years about 55 of each emitted Gt of C
has stayed in the atmosphere The rest has been absorbed byland or oceans Thus it takes about 38 Gt C per 1ppm ofatmospheric CO2
Conclusion
Conclusion IV
Emissions are about 13Gt C for 2013 The rate at whichatmospheric CO2 is increasing has risen from about 1ppmyr1960s to 2ppm for 2000rsquos Since there is lots of fuel weshould expect atmospheric CO2 to continue to increase and atan increasing rate lsquobusiness as usual scenarios call foratmospheric CO2e gt 800 within 100 years
Not all countries are the same They are responsible fordifferent shares have different per capita emissions useemission more or less efficiently and are responsible fordifferent shares of historical emissions These factors are veryimportant obstacles to international agreements and alsosuggest the need for a richer model
Conclusion
Conclusion V
Steady state CO2 emissions are probably very small Sternsuggests less than 13 of current Our calculations suggest(1-055)=45
Conclusion
Conclusion III
Each ppm of atmospheric CO2 corresponds to about 212 Gt C
and 778 Gt of CO2 Pay attention to the units people use
Not all gases are equal in their green house potential CO2 ismost common and most important but other gases are moreimportant per unit of emissions
Over the past 50 years about 55 of each emitted Gt of C
has stayed in the atmosphere The rest has been absorbed byland or oceans Thus it takes about 38 Gt C per 1ppm ofatmospheric CO2
Conclusion
Conclusion IV
Emissions are about 13Gt C for 2013 The rate at whichatmospheric CO2 is increasing has risen from about 1ppmyr1960s to 2ppm for 2000rsquos Since there is lots of fuel weshould expect atmospheric CO2 to continue to increase and atan increasing rate lsquobusiness as usual scenarios call foratmospheric CO2e gt 800 within 100 years
Not all countries are the same They are responsible fordifferent shares have different per capita emissions useemission more or less efficiently and are responsible fordifferent shares of historical emissions These factors are veryimportant obstacles to international agreements and alsosuggest the need for a richer model
Conclusion
Conclusion V
Steady state CO2 emissions are probably very small Sternsuggests less than 13 of current Our calculations suggest(1-055)=45
Conclusion
Conclusion IV
Emissions are about 13Gt C for 2013 The rate at whichatmospheric CO2 is increasing has risen from about 1ppmyr1960s to 2ppm for 2000rsquos Since there is lots of fuel weshould expect atmospheric CO2 to continue to increase and atan increasing rate lsquobusiness as usual scenarios call foratmospheric CO2e gt 800 within 100 years
Not all countries are the same They are responsible fordifferent shares have different per capita emissions useemission more or less efficiently and are responsible fordifferent shares of historical emissions These factors are veryimportant obstacles to international agreements and alsosuggest the need for a richer model
Conclusion
Conclusion V
Steady state CO2 emissions are probably very small Sternsuggests less than 13 of current Our calculations suggest(1-055)=45
Conclusion
Conclusion V
Steady state CO2 emissions are probably very small Sternsuggests less than 13 of current Our calculations suggest(1-055)=45
