Apportioning climate change indicators to regional emitters

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Apportioning climate change indicators to
regional emitters

• Jason Lowe
• September 2002

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Estimating regional share
CONCENTRATIONS FROM EACH COUNTRY/REGION
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Results Phase 1
Unless otherwise stated, results use EDGAR-HYDE
1.4 gas emissions.
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CDIAC Basic model (no feedback)
Temperature
CO2 Conc
CH4 Conc
N2O Conc
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CDIAC Extended model (feedback)
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CDIAC Basic model (no feedback)Short CH4 and
N2O lifetimes
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EDGAR/HYDE Basic model
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EDGAR/HYDE Extended model
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Can we simulate B1 CO2 concentrations using a
simple model? Input to HadCM3 is used as a
comparison
HadCM3 CO2 concentrations derived from Bern
carbon cycle model. Pre-1990 values agree well
with observations
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Can we simulate A1FI CO2 concentrations using a
simple model?Input to HadCM3 is used as a
comparison
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Can we simulate temperature rise using a simple
model? HadCM3 simulation is used as a comparison
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Results Phase 2
Unless otherwise stated, results use marginal
approach.
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Regional share of CO2 emissions
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Regional share of cumulative CO2 emissions
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Regional share of CO2 concentrations
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Regional share of GHG forcing
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Global temperature rise from regional emissions
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Regional share of temperature rise
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Share of the temperature rise to 2100
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Regional share of temperature rise annex 1 and
non-annex 1
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Regional share of temperature rise Only using
emissions after 1950
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Regional share of temperature riseOnly emissions
after 1990
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Are the results different for other scenarios?
A1FI
B1
A2
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Does feedback affect the apportionment
calculation?
No temperature feedback
Temperature feedback
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Does the amount of carbon cycle fertilization
affect the result?
Bern high case
Bern low case
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Does a slower climate response (only long time
constant) affect the result?
Slow climate model response
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Comparing attribution methods
All minus one
Marginal