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Integrating albedo into integrated assessment
Andrew D Jones, Katherine Calvin,William Collins, Jae Edmonds
LBNL - UC Berkeley - PNNL - JGCRI
Terrestrial Carbon Management
2
Reforestation & Afforestation
Avoided Deforestation
Biomass Harvest
Biofuels Long Term Sequestration
Land Use in Climate Mitigation Policy
• REDD/ REDD+ (Reduced Emissions from Deforestation and Degradation)
• Forestry and Ag Offset Programs
• GHG Inventories
• Biofuel (or Food) Life Cycle Assessment
3
4
Source - Bonan et al. AGU Fall 2010
Future Projections of Land Use Differ Widely
Lawrence, P. J., J. J. Feddema, G. B. Bonan, G. A. Meehl, B. C. O’Neill, S. Levis, D. M. Lawrence, K. W. Oleson, E. Kluzek, K. Lindsay, and P. E. Thornton (2011), Simulating the Biogeochemical and Biogeophysical Impacts of Transient Land Cover Change and Wood Harvest in the Community Climate System Model (CCSM4) from 1850 to 2100, Journal of Climate, in review.
Source - Jackson et al. Environ. Res. Lett.3 (2008) 044006
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Direct Biophysical Effects of Land Use Change
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Bonan, G. B. (2008), Forests and Climate Change: Forcings, Feedbacks, and the Climate Benefits of Forests, Science 320, 1444, doi:10.1126/science.1155121
Radiative Forcing (W/m2)
7
Source - IPCC AR4 Synthesis Report
Source - Jackson et al. Environ. Res. Lett.3 (2008) 044006
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Only albedo changes are counted in radiative forcing
How important is land-use change for future climate?
• How much and what kind of change will occur?
• What is the C cycle effect of land-use change?
• What is the biophysical effect of land-use change?
• How to understand both regional and global effects?
9
What’s in store
• Potential scale of albedo change (iESM)
• Account for albedo in GCAM
• Feedbacks when albedo included in targets
• Implications for assessment
10
How does treatment of land use change in
policy affect climate?
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Jones, A. D. et al. (2013), Greenhouse gas policies influence climate via direct effects of land use change, J of Climate, 26(11), 3657–3670, doi:10.1175/JCLI-D-12-00377.1.
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Universal Carbon Tax (UCT)
Fossil Fuel and Industrial Carbon Tax (FFICT)
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The Community Earth System Model (CESM)
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The Integrated Earth System Model (iESM)GCAM and GLM
EconomicsDemographicsEnergy SystemAg System
The Community Land Model
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Energy Water Carbon and Nitrogen
Do all RCP4.5 policies lead to same climate?
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Two Scenarios: 2005-2100
Universal Carbon Tax (UCT)Fossil Fuel and Industrial
Carbon Tax (FFICT)
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CO
2 C
once
ntra
tion
(ppm
)
Time Time
Identical forcing from greenhouse gases and aerosols
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Two Scenarios: 2005-2100
Fossil Fuel and Industrial Carbon Tax (FFICT)
Very different patterns of land use change
Universal Carbon Tax (UCT)
Change in Forest Cover from 2005 to 2100
Do all RCP4.5 policies lead to same climate?
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Temperature change from first (2005-2015) to last (2091-2100) decadeRCP4.5 UCT RCP4.5 FFICT
Global Mean Temp Change
NH Summer NH Winter
Temperature difference FFICT-UCT(decadal mean, 2090-2100 )
Annual Mean 50% Forest loss
Surface Albedo difference FFICT-UCT(decadal mean, 2090-2100 )
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Temperature change from first (2005-2015) to last (2091-2100) decadeRCP4.5 UCT RCP4.5 FFICT
Global Mean Temp Change
Actually RCP 3.9 !
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The IPCC “Parallel” Process
RCP’s
SSP’s
Climate Projections
Impacts &
Adaptationmatch based on RF
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A Problem
• Land-use is not accounted for in the forcing targets used to match RCP’s and SSP’s
• Thus, if SSP land-use diverges from the RCP’s, their climates no longer match
• Yet, land-use is an important socio-economic variable to be explored
Accounting for land-use forcing within GCAM
Forcing is determined by both surface and atmosphere
Compare worlds with all woody vegetation and all non-woody vegetation
Albedo forcing from removal of woody vegetation
Next Step: MODIS surface albedos
• More landcover types• Snow and snow-free conditions
Forcing from Land-Use Change
-0.30
-0.25
-0.20
-0.15
-0.10
-0.05
0.00
2005 2020 2035 2050 2065
W/m
2
Old Model
Ref
UCT
FFICT
Why is the forcing smaller?
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9./"0122345"
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Fore
st C
over
(M
km
^2)
Why is the forcing smaller?
latitude
land
con
vert
ed
(km
^2)
Effect of including albedo in policy targets
Carbon Price
Fossil Fuel Emissions
Land-Use Change Emissions
-50
0
50
100
150
200
250
300
350
400
450
2005 2020 2035 2050 2065
$/tC
Ref
Ref, w/ Endo Albedo
UCT
UCT, w/ Endo Albedo
FFICT
FFICT, w/ Endo Albedo 0
5
10
15
20
25
2005 2020 2035 2050 2065
GtC
/yr
-3
-2
-1
0
1
2
3
4
2005 2020 2035 2050 2065
GtC
/yr
Albedo Forcing
Forest and Shrub Cover
Bioenergy Crop Area
0
10
20
30
40
50
60
2005 2020 2035 2050 2065
mill
ion
km2
Ref
Ref, w/ Endo Albedo
UCT
UCT, w/ Endo Albedo
FFICT
FFICT, w/ Endo Albedo
0
1
2
3
4
5
6
7
2005 2020 2035 2050 2065
mill
ion
km2
Ref
Ref, w/ Endo Albedo
UCT
UCT, w/ Endo Albedo
FFICT
FFICT, w/ Endo Albedo
-0.30
-0.25
-0.20
-0.15
-0.10
-0.05
0.00
2005 2020 2035 2050 2065
W/m
2
0
20
40
60
80
100
120
SS
P1_
AFF
OR
ES
T
SS
P3_
AFF
OR
ES
T
SS
P3_
DE
LAY
SS
P3_
RE
DD
SS
P3_
DE
FOR
ES
T
mill
ion
km2
forest
shrubs
grass
pasture
biomass
crops
-0.35
-0.30
-0.25
-0.20
-0.15
-0.10
-0.05
0.00
2005 2020 2035 2050 2065 2080 2095
W/m
2 SSP1_AFFOREST SSP3_AFFOREST SSP3_DELAY SSP3_REDD SSP3_DEFOREST
Albedo in the SSP’s
2095 Land Cover Albedo
Some conclusions
• Albedo forcing (and climate effect) of land-use change can be quite significant
• Newer GCAM estimates lower rates of deforestation
• We can now diagnose albedo change within GCAM
• even more refined approach is coming
• Including albedo in forcing targets feeds back onto energy and land-use systems
• Less deforestation in FFICT despite forcing “bonus”
36
Photographer: Roman Makhmutov
Should we include albedo effects in policy?
37
Photographer: Roman Makhmutov
• non-radiative (e.g. hydro) effects• spatially concentrated effects
To what extent is land-use forcing equivalent
to GHG forcing ?
Have we solved the issue with the parallel process?
RCP’s
SSP’s
Climate Projections
Impacts &
Adaptationmatch based on RF
Toward a better assessment process
• Land-use change and GHG’s affect the climate in fundamentally different ways
• Same is true of aerosols
• Would we really consider a policy in which we reward aerosol emissions for cooling the planet?
• Then why do we consider RCP scenarios based on global RF targets?
• Maybe we should focus on the effect of individual forcings on regions of interest
39
Thank You!
40
41
Human
Activity
Climate
Forcing
Climate
OutcomesImpacts
Feedbacks
Ideally, forcing is a good proxy for impacts
Three Simulations
42
land forcing
CO2
forcingnet
forcing
Land Use Change Only
Equivalent CO2 Only
Land Use Change and Equivalent CO2
W/m2 W/m2 W/m2
-1 -1
+1 +1
-1 +1 0
Equilibrium response relative to pre-industrial
Three Simulations
43
+57 ppm
land forcing
CO2
forcingnet
forcing
Land Use Change Only
Equivalent CO2 Only
Land Use Change and Equivalent CO2
W/m2 W/m2 W/m2
-0.92 -0.92
+0.90 +0.90
-0.92 +0.90 -0.02
Equilibrium response relative to pre-industrial
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Global Scale Temperature Results
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Equivalent CO2 Warming
Land Use Change Cooling
Combined Effect With Trading
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global tempchange
% globe affected
mean abschange
LUC
CO2
TRADE
C % C
-0.57 62 0.60
0.74 99 0.76
0.17 76 0.55
Global Scale Temperature Results
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Latitudinal Precipitation Response
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global precipchange
% globe affected
mean abschange
LUC
CO2
TRADE
mm/y % mm/y
-12.7 36 58.9
14.8 30 36.8
2.5 36 55.0
Global Scale Precipitation Results
49
control
LUC
CO2
Differential Timing Effects
50
Forcing additivity does not hold
C(fLUC + fCO2) ≠ C(fLUC) + C(fCO2)
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But, response additvity does seem to hold
C(fLUC + fCO2) ≠ C(fLUC) + C(fCO2)
C(fLUC , fCO2) ≅ CLUC(fLUC) + CCO2(fCO2)
but...
+≅
52
Temperature Effects Revisited
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Precipitation Effects Revisited
