AA climateclimate scenarioscenario takingtaking intointo accountaccount landland--useusechangechange
Aurore VOLDOIRE, Jean-François ROYER
CNRM/GMGEC
OutlineOutline
Introduction :
Why take into account vegetation changes inside climate scenarios?
Why take into account land-use changes inside climate scenarios?
Chosen method : Coupling CNRM-CM3 with IMAGE2.2
Description of the coupling scheme
The simulation
Results
Simulated climate perspective
Vegetation perspective
Conclusions / Future work
WhyWhy include vegetationinclude vegetation changeschanges within climatewithin climate scenariosscenarios??
GCM
CO2
Other greenhousegases (GHGs)
CH4
N2O
CFC11
Ozonechemistry Ozone
precursors
CO
Halons
Aérosols
directeffect
indirecteffects
B2B1A2A1FA1TA1B
Vegetation
Importance of land useImportance of land use
Vegetation fraction Roughtness length
Zonal anomalies of surface properties[2090-2099] –[1970-1979]
[70N-90N]
[50N-70N]
[30N-50N]
[10N-30N]
[10S-10N]
[30S-10S]
[50S-30S]
[70S-50S]
map with cultures
natural vegetation
Introduction
Method
Results
Conclusion
TheThe chosen approachchosen approach
Vegetation mapGHG and aerosolconcentrations
TemperaturePrecipitation
Integrated impact
model
IMAGE2.2
(developed at RIVM, TheNetherlands)Alcamo et al. (1998)
General circulation Model
AOG
ARPEGE (atmosphere)OPA (ocean) –IPSL/LodycGELATO (sea ice)ISBA (land surface scheme)
Introduction
Method
Results
Conclusion
Modelling ofenergydemand
Scenario : demographic and economic projection= definition of the needs
Emissions and land use changes
RETROACTIONS
(simple) carbon cycle and atmospheric chemistry
EBM model of climate change (R and T)
Concentration changes
Model of evolution ofcontinental surfaces
(natural vegetation, cattle,cultures,…)
Hypothes on evolution of population and economy
Components ofComponents of thethe IMAGE modelIMAGE modelIntroduction
Method
Results
Conclusion
SimulationSimulation methodmethod ofof thethe vegetationvegetation covercover
Vegetation maps in2050 computed for the
A2 scenario
Potential vegetation
Cultures
Pâtures
F. jeune abandonnée
Plantation
Glace
Toundra
Toundra arbustive
F. boréale
F. de conifères
F. mixte tempérée
F. décidue tempérée
F. mixte chaude
Steppe
Désert
Arbustes
Savane
Savane boisée
F. tropicale
Natural vegetation
Actual vegetation
Introduction
Method
Results
Conclusion
Energydemand
Scenario
Emissions and land use changes
RETROACTIONS
(simple) carbon cycle and atmospheric chemistry
Climat
Concentration changes
continental surfaces
Hypotheses
Introduction of ARPEGE/OPA/GELATOIntroduction of ARPEGE/OPA/GELATO insideinside IMAGE2.2IMAGE2.2Introduction
Method
Results
Conclusion
Climate (CNRM-CM3)ARPEGE OPA
ISBA GELATOOASIS
Scénariod’émission-
concentration
T, P
IMAGE 2.2(RIVM)
O3Precursors
Vegetation mapsGHGs& Aérosols
Climatemeans
Ozone chemistryMOBIDIC
5 years
O3
ZonalTransports
AtmosphereARPEGE-Climat
Coupler
OceanOPAG
Sea iceGELATO
24 h
RiverroutingTRIP
CouplerOASIS
Coupler
Continental SurfacesISBA
Coupler
AOG
The coupling schemeThe coupling schemeIntroduction
Method
Results
Conclusion
ScenarioScenario simulationsimulation
IMAGE2.2
1765
Equilibration of thecarbon cycle model
•historicalemissions of CO2
•historicalconcentrations ofother GHGs
Evaluation ofvegetation mapswith the observedclimate
emissions due tosimulated land use,others are historical
CNRM-CM3
20 years of simulationwith constant forcings
(1970)
Forcings producedby IMAGE
Scenario
Full coupling
19901970 2100
First coupledsimulation with an A2
scénario:A2-IM-CM3
Introduction
Method
Results
Conclusion
SimulatedSimulated globalglobal temperaturetemperature changechangeIntroduction
Method
Results
Conclusion
CNRM-CM3forced by SRESconcentrations
CNRM-CM3coupled to
IMAGE
concentrationconcentration scenariosscenarios
Simulations desconcentrations parIMAGE
SRES scenarioThe concentration scenarios
produced by IMAGE do notdepend much on the thesimulated climatic change
The SRES concentrationscenario is not much differentfrom the IMAGE scenario
No explanation for the suddenchange observed in temperature
Abrupt change ofAbrupt change of thethe arcticarctic seasea--iceice covercover
Aire de la glace en Arctique
Tendance glissante sur 15 ans de l’aire de glace Arctique
95%
95%
99%
99%
Introduction
Method
Results
Conclusion
GeographicGeographic distribution ofdistribution of thethe warmingwarming
Date from which the IMAGE/CNRM-CM3 simulation stays warmer than theCNRM-CM3 in annual mean over the following 15 years
Region where thevegetation albedo issmaller when usingthe IMAGE vegetationmap
Introduction
Method
Results
Conclusion
SimulatedSimulated change ofchange of vegetationvegetation
Cultures
Pâtures
F. jeune abandonnée
Plantation
Glace
Toundra
Toundra arbustive
F. boréale
F. de conifères
F. mixte tempérée
F. décidue tempérée
F. mixte chaude
Steppe
Désert
Arbustes
Savane
Savane boisée
F. tropicale
1970 2100
Différence
Introduction
Method
Results
Conclusion
SeasonalSeasonal cyclecycle anomalyanomaly overover AmazoniaAmazonia
Daily thermal amplitude Precipitation
Total evaporation Evapotranspiration
Sensible heat flux
Computed as difference between the 2070-2099 and the 1960-1989 periods
Modification of the mean climate, but also of extremes :
IPCC standard simulation
Simulation with IMAGE
IPCC standard simulation
Simulation with IMAGE
-23941
+84436Maximum Nb ofconsecutive drydays
+33936
+13332Nb of days whereprécip > 10mm.j-1
Différence2070-20991960-1999
Introduction
Method
Results
Conclusion
PerspectivePerspective fromfrom IMAGEIMAGE
Evolution of cultivated surfaceover Amazonia
Evolution boral forest surfacenorth of 70°N
same scenariodifferent climates
Same climateapplied to
different scénarios
The surface of cultures is determined mainly by demographic constrainsts and by theevolution of agricultural practices climate is a secondary factor
Natural vegetation evolves mainly under the action of climate but is a slow phenomenon possible retroactions at longer term than the century
Introduction
Method
Results
Conclusion
SynthesisSynthesis
Though this work does not show clear evidence of an impact offuture vegetation changes on climate, it brings some usefulinformations :
Shows the feasibility of the IMAGE2.2-GCM coupling
An impact on climate is found locally (important in term ofvariability)
But no important retroaction is found at the decennal timescale
weak impact of climate on modeling of cultures inside IMAGE
The century time-scale is somewhat short to detect theappearance of a retroaction between natural vegetation changeand climate
Introduction
Method
Results
Conclusion
Future perspectivesFuture perspectives
Remarks :
To simulate only the natural evolution of vegetation is not realistic(the evolution of cultivated surfaces is very important)
The evolution of the surface of cultures depends mainly on thechosen economic scenario
Proposition :
Use of projections of land-use produced by IMAGE (or other impactAssessment Models) for each scenario directly in GCMs, in additionto simulations of natural vegetation dynamic vegetation models.
Introduction
Method
Results
Conclusion