Can We Avoid Dangerous Climate Change_09Jan2007

8/14/2019 Can We Avoid Dangerous Climate Change_09Jan2007

1/48

Global Warming:Can We Avoid

Dangerous Climate Change?

Jim Hansen

09 January 2007

Operation Sierra Storm

Television Meteorologists Conference


2/48


3/48


4/48


5/48


6/48


7/48

CO2, CH4 and temperature records from Antarctic ice core data

Source: Vimeux, F., K.M. Cuffey, and Jouzel, J., 2002, "New insights into Southern Hemisphere

temperature changes from Vostok ice cores using deuterium excess correction", Earth and PlanetaryScience Letters, 203, 829-843.


8/48

Ice Age ForcingsImply GlobalClimate Sensitivity~ C per W/m2.

Source:Hansen et al., Natl.Geogr. Res. & Explor., 9, 141,1993.


9/48

Global sea level extracted, via a hydraulic model, from an oxygen isotoperecord for the Red Sea over the past 470 kyr (concatenates SiddallsMD921017, Byrd, & Glacial Recovery data sets; AMS radiocarbon dating).Source: Siddall et al., Nature, 423, 853-858, 2003.


10/48


11/48

CO2,CH4 and estimatedglobal temperature

(AntarcticT/2in ice core era)0 = 1880-1899 mean.

Source:Hansen, Clim.Change, 68, 269, 2005.


12/48

Implications of Paleo Forcings and Response

1.Feedbacks (GHGs & ice area) are the chiefmechanisms for paleo temperature changes.

2.Instigators of climate change include: orbitalvariations, any other small forcings, chaos.

3. Climate on long time scales is very sensitive toeven small forcings.

4.Another ice age cannot occurunless humans

become extinct.5.Humans now control global climate, for better

or worse.


13/48

Climate forcing agents in the industrial era. Effective forcing accounts forefficacy of the forcing mechanism

Source:Hansen et al., JGR, 110, D18104, 2005.


14/48

Climate Forcings Since 1880

Source:Dangerous human-made interference with climate: A GISS modelE study, submitted


15/48

Source:Earth'senergy imbalance:Confirmation andimplications. Science308, 1431, 2005.

(A) Forcings

used to driveclimatesimulations.

(B) Simulatedand observedsurface

temperaturechange.

2 t C Gl b l W i


16/48

21st Century Global Warming

Climate Simulations for IPCC 2007 Report

Climate Model Sensitivity 2.7-2.9C for 2xCO2(consistent with paleoclimate data & other models)

Simulations Consistent with 1880-2003 Observations(key test = ocean heat storage)

Simulated Global Warming < 1C in Alternative Scenario

Conclusion: Warming < 1C if additional forcing ~ 1.5 W/m2

Source:Hansen et al., to be submitted to J. Geophys. Res.


17/48

United Nations

Framework Convention on Climate Change

Aim is to stabilize greenhouse gas emissions

at a level that would prevent

dangerous anthropogenic interference

with the climate system.


18/48

Metrics for Dangerous Change

Extermination of Animal & Plant Species1. Extinction of Polar and Alpine Species2. Unsustainable Migration Rates

Ice Sheet Disintegration: Global Sea Level1. Long-Term Change from Paleoclimate Data2. Ice Sheet Response Time

Regional Climate Change1. General Statement2. Droughts/Floods


19/48

Photos Mark Payne-Gill, naturepl.com; 2005 National Geographic Society. All rights reserved.

Armadillos: One of the Surviving Species?


20/48

Arctic Climate Impact Assessment (ACIA)

Sources: Claire Parkinson and Robert Taylor


21/48

Survival of Species

1. Business-as-Usual Scenario- Global Warming ~ 3C- Likely Extinctions ~ 50 percent

2. Alternative Scenario

- Global Warming ~ 1C

- Likely Extinctions ~ 10 percentClimate Feedbacks Scenario Dichotomy


22/48

Increasing Melt Area on Greenland

2002 all-time record melt area Melting up to elevation of 2000 m 16% increase from 1979 to 2002 70 meters thinning in 5 years

Satellite-era record melt of 2002 was exceeded in 2005.Source:Waleed Abdalati, Goddard Space Flight Center

S f M lt G l d


23/48

Melt descendinginto a moulin,a vertical shaftcarrying water

to ice sheet base.

Source: Roger Braithwaite,University of Manchester (UK)

Surface Melt on Greenland


24/48

Jakobshavn Ice Stream in Greenland

Discharge from majorGreenland ice streamsis accelerating markedly.

Source: Prof. Konrad Steffen,Univ. of Colorado


25/48

Greenland Mass Loss From Gravity Satellite


26/48

Location and frequency of glacial earthquakes on Greenland.Seismic magnitudes are in range 4.6 to 5.1.Source: Ekstrom, Nettles and Tsai, Science, 311, 1756, 2006.

Earthquake Locations Annual Number of Quakes*

* 2005 bars capture only first 10 months of 2005

Glacial Earthquakes on Greenland


27/48

Areas Under Water: Four Regions


28/48

Summary: Ice Sheets

1. Human Forcing Dwarfs Paleo Forcingand Is Changing Much Faster

2. Ice Sheet Disintegration Starts Slowlybut Multiple Positive Feedbacks CanLead to Rapid Non-Linear Collapse

3. Equilibrium Sea Level Rise for ~3CWarming (2510 m = 80 feet) Impliesthe Potential for Us to Lose Control


29/48

Simulated precipitation change in response to climate forcings estimated for 1880-2000.

Source: Hansen et al., JGR110, D18104, 2005.


30/48

Expected Precipitation Changes

1. Increased Precipitation- Tropical Rain-Belt over Ocean- Polar Regions

2. Increased Drought in Subtropics- Western United States- Mediterranean Region

BAU Super-Drought in U.S. WestIncreased Fires Scorched Earth


31/48

SST in Pacific Warm Pool (ODP site 806B, 0N, 160E) in past millennium.Time scale expanded in recent periods. Data after 1880 is 5-year mean.Source:Medina-Elizalde and Lea, ScienceExpress, 13 October 2005;data for 1880-1981 based on Rayner et al., JGR,108, 2003, after 1981 on Reynolds and Smith, J. Climate, 7, 1994.

kyr Before Present Date


32/48


33/48

Fossil Fuel Reservoirs

and 17502004 Emissions

0

200

400

600

800

1000

1200

1400

Oil Gas Coal

GtC

Reserve growth

Proven reserves*

Emissions (CDIAC)

EIA

IPCC

CO2

(ppm

v)

600

400

200

100

300

0

500

*Oil & gas from EIA

**Unconventional oil & gas; uncertain,

could be large

Other

Methane

Hydrates

Shale

Oil

Tar Sands

? **


34/48

Science & Implications

1. Warming >1C Risks Different Planet- Maximum CO2 ~450 ppm

- Somewhat greater if non-CO2

2. Gas + Oil Use Most of 450 ppm Limit- Coal/unconventional must sequester CO2- Gas + Oil supplies must be stretched

3. Quarter of CO2 Stays in Air Forever- Eventual Vehicles must be Zero-CO2(renewable, hydrogen from nuclear or solar, etc.)

- Eventual Power Plants must be Zero-CO2


35/48

Inferences (Opinions)

1. Building/Vehicle Efficiencies Critical- Needed to Stretch Oil/Gas Supplies- Needed for Future Non-Carbon Energy

2. Both Incentives and Standards Needed- Rising Price on Carbon Drives Innovation- Efficiency Standards Proven Effective

3. United States Leadership Essential- Large Emissions, Tech & Political Leader- Developing Countries cannot be expectedto act until the U.S. Takes First Step


36/48

Fossil Fuel Facts & Opinions1. Value Fossil Fuels >> Mining Cost

- $$$$ Pocketed by Middle East & Russia- Those $$$$ Fund Many Things

2. Steadily Rising Carbon Tax- Can Be Revenue Neutral

- Nonpartisan Tsar Adjusts Rate (a la Fed. Res.)- Spurs Technology Devel. & Efficiency- Energy Need per GDP Decreases

3. Results

- Energy Independence & National Security- $$$$ to U.S. Treasury, not Middle East/Russia- Improves U.S. International Competitiveness- Good High-Tech High-Pay Jobs in the U.S.


37/48


38/48

Summary: Is There Still Time?

Older Generation Swampedby Near-term Problems

Need Action Soon: Decade BAU

Eliminates Alternative ScenarioPotential Legacy: Great Moral

Burden, Perhaps a Legal One

Best Hope: Young GenerationBecomes Informed and Involved


39/48

Final Question:

Larry King Has Said: Nobody

Cares About 50 Years From Now

Who Is He Speaking For?


40/48


41/48

Ozone Success Story

1.Scientists: Clear warning

2.Special Interests: Denied story for years, butdeveloped ozone-friendly technology

3.Media: Transmitted the message well

4.Public: quick response; spray cans replaced;concern of public was clear to lawmakers

5.Government: U.S./Europe leadership; allow delay& technical assistance for developing countries

Result: No additional CFC-producing infrastructure built


42/48

Global Warming Story

1.Scientists: Fail to clearly distinguishclimate change & BAU = A Different Planet

2.Special Interests: Disinformation campaigns,emphasis on short-term profits

3.Media: False balance, & leap to hopelessness

4.Public: understandably confused, uninterested

5.Government: Aids and abets special interests;fails to lead no Winston Churchill today

Result: CO2 emissions continue to increase at BAU rate


43/48

s it appears that the world may pass a tipping point soon, beyond which it will be

impossible to avert massive future impacts on humans and other life on the planet:Who Bears (Legal/Moral) Responsibility?

1.Scientists?

2.Media?

3.Special Interests?4.U.S. Politicians?

5a.Todays U.S. Public?

5b.U.S. Children/Grandchildren?

Who Will Pay?


44/48


45/48

Source:Hansen et al.,J. Geophys. Res.,submitted.

Temperature changeobserved and simulated

for different forcingmechanisms.

Aerosol forcing(negative) is thought tobe slightly excessive inin the all forcingsimulation.

Workshop at East West Center Honolulu


46/48

April 4-6, 2005; Local Host: Intnl. Center for Climate & Society, Univ. Hawaii

Workshop at East-West Center, Honolulu

Air Pollution as Climate Forcing: A Second Workshop

Multiple Benefits by Controlling CH4 and CO(benefits climate, human health, agriculture)

Multiple Benefits from Near-Term Efficiency Emphasis(climate & health benefits, avoid undesirable infrastructure)

Targeted Soot Reduction to Minimize Warming from Planned Reductions ofReflective Aerosols

(improved diesel controls, biofuels, small scale coal use) Targeted Improvements in Household Solid Fuel Use

(reduces CH4, CO, BC; benefits climate, human health, agriculture)

Conclusion: Technical Cooperation Offers Large Mutual Benefits to Developed& Developing Nations.

References:Air Pollution as Climate Forcing: 2002 Workshop; 2005 Workshop http://www.giss.nasa.gov/meetings/pollution02/ and 2005/

U.S. Auto & Light Truck CO2 Emissions


47/48

g 2

Source:On the Road to ClimateStability, Hansen, J., D. Cain andR. Schmunk., to be submitted.

Moderate Action is NRCPath 1.5 by 2015 and

Path 2.5 by 2030.

Strong Action addshydrogenpowered vehiclesin 2030 (30% of 2050 fleet).

Hydrogen produced fromnonCO2 sources only.


48/48

United States annual savings (at $50/barrel, todays dollars) in 2030 for alternativeautomotive efficiency improvements.

Date post:	30-May-2018
Category:	Documents
Upload:	eternal-spring
View:	216 times
Download:	0 times

Can We Avoid Dangerous Climate Change_09Jan2007

Documents