Present and future contributions of the household sector to emissions of black carbon in China
Present and future contributions of the household sector to emissions of black carbon in China
David G. StreetsArgonne National Laboratory
Workshop on the Mitigation of Air Pollution and Climate Change in China
Oslo, Norway
October 17-19, 2004
The source of carbonaceous aerosols is unburned carbon emitted during inefficient combustion of fuel
Technically, we are most concerned about:
black carbon (BC), fine aerosol particles generally smaller than 1 micrometer in diameter and mostly elemental carbon,
and
organic carbon (OC), similar particles in which the carbon is bonded to other atoms.
These particles are small enough to travel in the air for a week or more, forming regional air pollution and ultimately being deposited far from the source.
Kathmandu: Brick KilnsKathmandu: Brick Kilns
Harmful Effects of BC
Human health! Particles are small enough to be inhaled into the deep lung where they slow clearance mechanisms and provide absorption sites for toxic species
Soiling of surfaces of buildings, monuments, homes, etc.
Reduced visibility Reduction in crop yields due to lowered insolation Possible surface damage to vegetation Modification of regional and global climates:
temperature and precipitation changes, effects on cloud formation
A new bar chart of radiative forcing was constructed by Jim Hansen to replace the IPCC formulation
(Hansen et al., Senate testimony, May 1, 2001;Hansen and Sato, PNAS)
BlackCarbon (0.8)
Net forcing = 1.6 +/- 1.1 W/m2
Model-simulated summer changes in temperature
Model suggests a cooling of 0.5 to 1 deg K over China
due to reduction in radiation reaching
the surface; in other parts of the world,
the surface is warmed due to BC
heating
From Menon et al., Science, 297, 2250-2253, 2002
Model-simulated summertime changes in precipitation
The model suggests decreased
precipitation in northern China (drought) and
increased precipitation in southern China
(flooding) due to BC aerosols
From Menon et al., Science, 297, 2250-2253, 2002
Jim Hansen’s “Alternative” Scenario(released August 29, 2000)
“Our analysis of climate forcings suggests, as a strategy to slow global warming, an alternative scenario focused on reducing non-CO2 GHGs and black carbon (soot) aerosols.… (R)eductions in tropospheric ozone and black carbon would not only improve local health and agricultural productivity but also benefit global climate and air quality.”
J. Hansen, M. Sato, R. Ruedy, A. Lacis, and V. Oinas, Global warming in the twenty-first century: an alternative scenario, Proceedings of the National Academy of Sciences, 97, 9875-9880, 2000
Global distribution of BC emissions in 1996:it’s mostly China, India, and biomass burning
China contributes about one-fourth of global BC
Coal-burning cook stovesin Xi’an, China
Inefficient combustion of coal in small stoves in China produces large quantities of black carbon
Results: Most of the BC in China comes from the domestic/residential sector
Industry (Gg)
Domestic (Gg)
Transport (Gg)
Pow er Generation(Gg)
Biomass Burning(Gg)
Emissions in China are about 1 million tons per year of BC and 3.4 million tons per year of OC
Ground-level sources(residential, transport)
Second-layer sources(industry)
Distribution of black carbon emissions in East Asia by source type and release height, reveals the regional nature of the
problem (2008 Beijing Olympics?)
Often,
[Global, India, China, …]
BIOMASS BURNING
ENERGY USE
BC EMISSION FACTORS
SOURCE TESTING
BC EMISSIONS
BC ANALYSIS METHODS
ATMOSPHERIC MODELING
MONITORING CAMPAIGNS
CALCULATED BC
CONCENTRATIONS
OBSERVED BC
CONCENTRATIONS
( )( )
( )CALC
OBS
2 4
There are still fundamental problems with our understanding of BC in the atmosphere
Approach to forecasting BC and OC emissionsfrom the 1996 base-year reference point
From Bond et al., JGR, 2004
“Give me a future, any future…”(Range of IPCC forecasts of temperature change)
(Courtesy of Loretta Mickley)
A1B and B1 used in ICAP
A2 and B2 done subsequently
2030 and 2050 done
Major factors influencing future BC emissions:
Level:
1 Change in energy use and fuel type, by sector and world region
2 Improvements in particle control technology
3 Shifts in technology from low-level to higher-level technology/fuel combination
4 Improvements in emission performance of a given technology/fuel combination
Which fuels are used in which sectors?
China photo courtesy of
Bob FinkelmanResidential coal use has very high
BC emissions
Residential electricity use from nuclear power has zero BC emissions
Level 1 forecasting
Fuel use is partitioned among sectors and technology types(this example is part of the residential sector)
Tech Code Fuel1 Combustor/Control Canada USA
Central America
South America
Northern Africa
Western Africa
Eastern Africa
Residential 33378 218121 167410 199539 97470 450412 162794122 Agricultural Wastes General 0 0 0 0 465 5696 4296123 Animal Wastes General 0 0 0 1631 169 183988 1504899 Biofuel Fireplace 1503 12515 0 0 0 0 0
127 Biofuel Heating Stove 4510 37545 0 0 0 0 01 Biofuel Improved Cookstove 0 0 2434 3821 355 8439 4398
44 Biofuel Open Fire 0 0 14605 22926 2130 50632 26391134 Biofuel Stoker/No control 0 0 0 0 0 0 0
2 Biofuel Traditional Cookstove 0 0 31644 49674 4615 109703 57180124 Biofuel Total Biomass 0 0 0 0 0 0 0152 Biofuel Charcoal Production 0 0 5176 36411 1096 34969 4031894 Briquettes General 0 0 14 0 0 4913 8381 Brown Coal General 18 0 0 0 0 636 084 Charcoal General 0 0 1202 1860 274 3865 588952 Coking Coal General 0 0 0 0 0 0 0
146 Diesel Fuel External Combustion 6000 17722 1844 2683 0 0 0147 Diesel Fuel Generator 0 0 1844 2683 37462 7425 858128 Hard Coal Heating Stove 100 2651 0 0 0 0 098 Hard Coal Open Fire 0 0 0 644 0 3872 0
120 Hard Coal Stoker/Cyclone 0 0 0 0 0 0 0121 Hard Coal Stoker/No control 0 0 0 0 0 0 0
A stove is a stove is a…(tech/fuel shifts for a particular energy service)
Photo of street vendor’s stove in Xi’an, courtesy of Beverly Anderson
Coal-fired, high BC
Gas or electric, low BC
Level 3 forecasting
Net BC emission factors (g/kg) are developed from PM ef’s, C fractions, and sub-micron fractions
Tech Code Fuel1 Combustor/Control Canada USA
Central America
South America
Northern Africa
Western Africa
Eastern Africa
Southern Africa
Power68 Biofuel General 0.03869 0.03869 0.03869 0.03869 0.03869 0.03869 0.03869 0.03869
117 Briquettes Stoker/Cyclone 0.00156 0.00156 0.00156 0.00156 0.00156 0.00156 0.00156 0.0015641 Brown Coal Pulverized Coal/Cycl 0.00104 0.00104 0.00104 0.00104 0.00104 0.00104 0.00104 0.0010439 Brown Coal Pulverized Coal/ESP 0.00021 0.00021 0.00021 0.00021 0.00021 0.00021 0.00021 0.0002140 Brown Coal Pulverized Coal/Scrub 0.00940 0.00940 0.00940 0.00940 0.00940 0.00940 0.00940 0.0094072 Brown Coal Stoker/Cyclone 0.03740 0.03740 0.03740 0.03740 0.03740 0.03740 0.03740 0.03740
119 Brown Coal Stoker/ESP or Filter 0.00374 0.00374 0.00374 0.00374 0.00374 0.00374 0.00374 0.0037471 Brown Coal Stoker/Scrubber 0.08415 0.08415 0.08415 0.08415 0.08415 0.08415 0.08415 0.0841551 Coking Coal General 0.00000 0.00000 0.00000 0.00000 0.00000 0.00000 0.00000 0.0000066 Coking Coal Stoker/Scrubber 0.00000 0.00000 0.00000 0.00000 0.00000 0.00000 0.00000 0.0000057 Diesel Fuel General 0.00265 0.00265 0.00265 0.00265 0.00265 0.00265 0.00265 0.00265
112 Hard Coal Cyclone/Cyclone 0.00059 0.00059 0.00059 0.00059 0.00059 0.00059 0.00059 0.00059110 Hard Coal Cyclone/Filter or ESP 0.00002 0.00002 0.00002 0.00002 0.00002 0.00002 0.00002 0.0000222 Hard Coal Pulverized Coal/Cycl 0.00018 0.00018 0.00018 0.00018 0.00018 0.00018 0.00018 0.0001820 Hard Coal Pulverized Coal/ESP 0.00007 0.00007 0.00007 0.00007 0.00007 0.00007 0.00007 0.0000721 Hard Coal Pulverized Coal/Scrub 0.00288 0.00288 0.00288 0.00288 0.00288 0.00288 0.00288 0.0028869 Hard Coal Stoker/Cyclone 0.03465 0.03465 0.03465 0.03465 0.03465 0.03465 0.03465 0.0346519 Hard Coal Stoker/ESP or Filter 0.00554 0.00554 0.00554 0.00554 0.00554 0.00554 0.00554 0.0055470 Hard Coal Stoker/Scrubber 0.11088 0.11088 0.11088 0.11088 0.11088 0.11088 0.11088 0.1108850 Heavy Fuel Oil General 0.03960 0.03960 0.03960 0.03960 0.03960 0.03960 0.03960 0.0396047 Natural Gas General 0.00012 0.00012 0.00012 0.00012 0.00012 0.00012 0.00012 0.0001265 Waste, Municipal General 0.00176 0.00176 0.00176 0.00176 0.00176 0.00176 0.00176 0.00176
Emission factors for a given tech/fuel combination aredetermined using an S-shaped technology penetration curve
0.00
1.00
2.00
3.00
4.00
5.00
6.00
7.00
1 6 11 16 21 26 31 36 41 46 51
Em
iss
ion
rat
e (g
/kg
)
Time (years)
1996 current emission factor (Bond/Streets)
“Ultimate” performance
Shape factor depends on lifetime, build rate, etc.
“Net” performance
in 2030
Recent fuel use and BC emission trendsin East Asia (≈ China)
Figure 1 Fuel Use Trends in East Asia
0
500000
1000000
1500000
2000000
2500000
3000000
1980 1985 1990 1995 2000
Year
Fuel
Use
(Gg)
TotalResidentialIndustryPowerTransportBiomass Burning
Figure 2 BC Emission Trends in East Asia
0
500
1000
1500
2000
2500
1980 1985 1990 1995 2000
Year
BC
Em
issi
ons
(Gg)
TotalResidentialIndustryPowerTransportBiomass Burning
Fuel Use
BC Emissions
Future trends in BC emissions from the household sector
BC Emissions from the Household Sector
0
200
400
600
800
1000
1200
1400
1600
1800
1970 1990 2010 2030 2050
Year
BC
Em
iss
ion
s (
Gg
)
A1B Scenario
A2 Scenario
B1 Scenario
B2 Scenario
Future trends in BC emissions fromresidential coal use
BC Emissions from Coal Use
0
200
400
600
800
1000
1200
1970 1990 2010 2030 2050
Year
BC
Em
iss
ion
s (
Gg
)
A1B Scenario
A2 Scenario
B1 Scenario
B2 Scenario
Future trends in BC emissions from fuelwood use
BC Emissions from Fuelwood Use
0
20
40
60
80
100
120
140
160
1970 1980 1990 2000 2010 2020 2030 2040 2050 2060
Year
BC
Em
issio
ns (
Gg
)
A1B Scenario
A2 Scenario
B1 Scenario
B2 Scenario
Future trends in BC emissions from stoves
BC Emissions from Fuelwood Stoves (A2 Scenario)
0
10
20
30
40
50
60
70
80
90
1970 1990 2010 2030 2050
Year
BC
Em
iss
ion
s (
Gg
) Heating Stove
ImprovedCookstoveTraditionalCookstove
Future trends in BC emissions from residentialuse of crop residues
BC Emissions from Crop Residues
0
50
100
150
200
250
300
350
1970 1980 1990 2000 2010 2020 2030 2040 2050 2060
Year
BC
Em
issi
on
s (G
g)
A1B Scenario
A2 Scenario
B1 Scenario
B2 Scenario
The changing picture of residentialBC emissions in China
Residential BC Emissions in 2000
Crop Residues
Animal Waste
Municipal Waste
Fuelwood
Coal
Oil, LPG
1980: mainly
coal
2030A2: mainly crop
residues
2000: coal, wood, crops mixture
Shares of Residential BC Emissions in 1980
Crop Residues
Animal Waste
Municipal Waste
Fuelwood
Coal
Oil, LPG
Shares of Residential BC Emissions in 2030 (A2 Scenario)
Crop Residues
Animal Waste
Municipal Waste
Fuelwood
Coal
Oil, LPG
We desperately need more source testing inChina to improve emission factors
Representativeness of entire population of sources
Typical operating practices (air flow)
Typical fuels and fuel characteristics
Relationship to similar sources in the developed world
Daily and seasonal operating cycles
Embracing BC offers the possibility of a true global compact to address climate change
U.S. and Europe (and other developed countries) reduce CO2
They are the cause of most of the accumulated CO2
They can afford the more expensive measures of CO2 mitigation
They will accrue ancillary energy security benefits They can contribute a long-term solution
China and India (and other developing countries) reduce BC They are the cause of most of the emitted BC They can afford the less expensive measures of BC control They will accrue ancillary health benefits They can contribute a near-term solution
Conclusions
Black carbon in China today is a serious environmental problem, leading to (largely unquantified) inhalation health effects, regional ecological damage, and climate modification.
The major causes are the direct combustion of solid fuels in the home, poor combustion efficiency and lack of PM controls in the industrial sector, polluting vehicles, and open biomass burning.
In the future, we think that the gradual phase-out of inefficient technologies will slowly reduce primary aerosol emissions; more vehicles, however, will tend to increase emissions. In the household sector, things should improve rapidly in urban areas, but linger in rural areas.
BC control could be China’s contribution to a global warming treaty.
