1. Process oriented evaluation of coupled climate-carbon cycle models
Pierre Friedlingstein, IPSL/LSCE, France
+ contributions from L. Bopp, P. Cadule, C. Jones, S. Piao, and J. Randerson
C4MIP in IPCC AR4
Climate projections
Climate feedback on Carbon Cycle
C4MIP models
AOGCMs
730 – 1000 ppm
Positive feedback (larger warming), but large uncertainty in simulated atmospheric CO2.
Essentially driven by uncertainty in carbon cycle response to climate change
At that time, no proper model evaluation
C4MIP models
Atmospheric CO2 difference (ppm)
Change in Land Uptake (GtC)
2.4 – 5.6 °C
2.6 – 4.1 °C
Surface Temperature Change (K)
Friedlingstein., et al, 2006
Meehl ., et al, 2007
C4MIP in CMIP5
Multiple constrains from observations
C4MIP Umbrella
Atmospheric CO2 (trends and var.)
Leaf Area Index (Greening)
Benchmark against 20th century
Constrains on processes driving climate-carbon feedback
Reduced uncertainty on
Climate-carbon cycle gain
Compatible emissions
Climate projections
Ocean Carbon Inventory (trend)
Air-Sea CO2 exchange (trends and var.)
I-LAMB