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U.N. FCCC, Bracknell, 25-27 Sep 2002 Experts Meeting on Assessment of Contributions to Climate Change Michael Prather University of California at Irvine Completeness & Assessment: What forcings are / should be included? Validation: - PowerPoint PPT Presentation
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U.N. FCCC, Bracknell, 25-27 Sep 2002
Experts Meeting on Assessment of Contributions to Climate Change
Michael Prather
University of California at Irvine
Completeness & Assessment:What forcings are / should be included?
Validation:What are the minimum capabilities in simulating the current climate system?
E S S
What Greenhouse Agents are listed under Kyoto ?
Annex A
Carbon dioxide (CO2)
Methane (CH4)
Nitrous oxide (N2O)
Hydrofluorocarbons (HFCs)
Perfluorocarbons (PFCs)
Sulfur hexafluoride (SF6)
What are not ?
CFCs & HCFCs (Montreal - OK)
Sulfate Aerosols
Black & Organic Carbon Aerosols
Tropospheric Ozone (O3)
Carbon monoxide (CO)
Nitrogen Oxides (NOX)
What about indirect greenhouse gasesunder Kyoto ?
What Greenhouse Agents are forcing climate ?
Which Greenhouse Agents have a good historical record ?
CO2
CH4
N2O
CFCs
solar
strat O3
trop O3
sulfate
fossil fuel OC/BC
biomass OC/BC
mineral dust
aerosol indirect land use /albedo
Which Greenhouse Agents are attributable ?
Anthropogenic control of the old GHGases
CH4 emissions (600 Tg-CH4/yr)
fossil fuels17%
biomass burning 5%
landfills 7%
ruminants14%
rice 9%
pollution (lifetime) ??%
N2O emissions (16 Tg-N/yr)
industrial processes 7%
biomass burning 3%
agriculture24%
cattle/feedlots 12%CFC & HCFC emissions (<< 1 Tg/yr)
refrigeration, foam, propellant, cleaning
phased out under Montreal Protocol
Anthropogenic control of the new GHGases
PFCs = CF4 + ... (13 Gg/yr ++)
anthropogenic***100%
aluminum, industrial
SF6 emissions (6 Gg/yr ++)
anthropogenic 100%
insulation, electrical switches
HFC emissions (100 Gg/yr ++)
anthropogenic 100%
CFC partial replacements
Anthropogenic control of Aerosols
sulfate = SO2 emissions (110 Tg-S/yr)
fossil fuels 67%
biomass burning 2%
Black Carbon emissions (12 Tg/yr)
fossil fuels 55%
biomass burning 45%
Carbonaceous emissions (140 Tg/yr)
fossil fuels 20%
biomass burning 39%
Anthropogenic control of the pollution gases
CO emissions (2800 Tg-CO/yr)
fossil & domestic fuel 32%
biomass burning 25%
NOX emissions (52 Tg-N/yr)
fossil fuels 65%
biomass burning 14%
agriculture/soils 12%
VOC emissions (600 Tg-C/yr)
fossil fuel 28%
biomass burning 6%
CH4
CO is an indirect greenhouse gas
CO emissions are effectively
equivalent to CH4 emissions:
100 Tg-CO = 5 Tg-CH4(IPCC, TAR)
OHCO O3
Anthropogenic Impact through Reactive Pollutants1750 - 2000
18002000 O3 OH
CH4 +4.6 DU - 30 %
NOX +4.1 + 14
CO +1.2 - 11
VOC +0.5 - 5
sum +10 DU - 32 %
“observed” +9 (±4) ??
Effective Reactive Pollutant contribution to CH4
CH4 320 Tg(CH4)/y = direct emission
NOx 40 Tg(N)/y - 80 Tg(CH4)/y
CO 1000 Tg/y + 50 Tg(CH4)/y
VOC 250 Tg/y + 30 Tg(CH4)/y
Validation of key components from the historical record is essential for credibility.
Why do this just to get relative impacts?
If the historical record in poorly reproduced, then the ‘model’ is in error or is missing key components of climate change this challenges the accuracy of even the relative national impacts and makes the process likely to fail an IPCC review
What does this validation test?
Both models and emissions
Validation of key components from the historical record is essential for credibility.
What is the minimal set of historical climate parameters that (i) should be reproducible by simple models and (ii) provides critical tests of the climate change to date.
FORCING
CO2 record, CH4 record, aerosols ???
RESPONSE
surface T (NH vs. SH ?), ocean Heat Content ?
sea level rise
CO2 (ppm) - Battle/Etheridge
290
310
330
350
370
1880 1900 1920 1940 1960 1980 2000
CH4 (ppb) - Battle/Etheridg
800
900
1000
1100
1200
1300
1400
1500
1600
1700
1800
1880 1900 1920 1940 1960 1980 2000
mean CO2 & CH4
1880 – 2000
Surface Temperature
1860 – 2000
? NH – SH
shows effect of aerosols
Ocean Heat Content (upper 300 m)
1945 – 2000
Sea Level Rise
1800 – 2000
Validation of key components from the historical record is essential for credibility.
What combination of historical data does it take to demonstrate that the “relative attribution” calculation is valid & without systematic errors ?
total “attributable” forcing
(missing sources)
correct chemistry/carbon model
(affects time-weighting of emissions)
correct indirect forcing
correct climate sensitivity
(affects time-weighting of forcing)