PKU – LSCE workshop on radiative forcing
attribution - Introduction
P. Ciais
PKU-LSCE workshop on radiative forcing
Oct 2-3 2012
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Radiative forcing per ton emmitted
Evolution of RF after an instaneous emission of
different GHGs
Year after the perturbation
PKU-LSCE workshop on radiative forcing
Oct 2-3 2012
2/10
Long time scales for the removal of an excess of CO2
(RF) in the atmosphere induced by emissions
PKU-LSCE workshop on radiative forcing
Oct 2-3 2012
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expected re
GHG with
down
curveRF
to the
attemps
the first
- constitute
Shorter time
scales
for
induced
by CH4,
at the end of the century?
O3 and aerosols emissions
- or produce effects at a shorter term?
Quantitative differences between gases is scenario dependent,
but on longer time scales the effect of CO2 remains dominant
PKU-LSCE workshop on radiative forcing
Oct 2-3 2012
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Comparison of RF induced by CH4 and CO2 permanent
mitigation, instantaneous vs. cumulative
Compared radiative forcing diminution when suppressing:
-a permanent source of 1kg of CO2 per year
-a permanent source of 21 kg of methane per year
The cumulated effect of CO2
becomes dominant only
after 250 years approximately
(B. Dessus et al)
PKU-LSCE workshop on radiative forcing
Oct 2-3 2012
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Comparison of RF induced by LUC and
greenhouse gas emissions for a process in the
Earth System (here, a boreal fire)
GHG and O3 warming
Albedo cooling
PKU-LSCE workshop on radiative forcing
Oct 2-3 2012
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The next steps, towards the separation of the
contribution of different regions
• IPCC
Y
E
Q
RF
T°
Production
Emissions
Concentrations
Radiative Forcing
Temperature
Globe
[with reg
details]
Globe
Globe
[with
spatial
details]
Globe
[with
spatial
details]
[with
spatial
details]
Globe,
[with spatial
details]
• This workshop
Y
E
Q
RF
T°
Production
Emissions
Concentrations
Radiative Forcing
Temperature
Globe
China &
globe
China &
Globe
PKU-LSCE workshop on radiative forcing
Oct 2-3 2012
Not adressed
7/10
Example of aerosol concentration attribution to
regions
PKU-LSCE workshop on radiative forcing
Oct 2-3 2012
Koch et al. 2007 8/10
Example of aerosol RF attribution to regions and
to anthropogenic / natural processes
PKU-LSCE workshop on radiative forcing
Oct 2-3 2012
Koch et al. 2007 9/10
Objectives of this workshop
• Present new emissions over China and their
uncertainties (compare with IPCC inventories)
• Include anthropogenic emissions and natural ones
• Methods to calculate separately RF from China and
rest of the globe induced by the emissions
• Implications for RF changes over China and rest of
the globe, on different time scales
• Try to separate anthropogenic and natural
contributions
PKU-LSCE workshop on radiative forcing
Oct 2-3 2012
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