Pierre Friedlingstein, IPSL/LSCE, France+ contributions from L. Bopp, P. Cadule, C. Jones, S. Piao, and J. Randerson

Process oriented evaluation of coupled climate-carbon cycle models

2.6 – 4.1 °C

2.4 – 5.6 °C

730 – 1000 ppm

C4MIP in IPCC AR4Climate feedback on Carbon Cycle

Climate projections

Friedlingstein., et al, 2006Meehl ., et al, 2007

Atm

osp

her

ic C

O2

dif

fere

nce

(p

pm

)

Ch

ang

e in

Lan

d U

pta

ke (

GtC

)

Surface Temperature Change (K)

C4MIP in CMIP5Multiple constrains from observations

Atmospheric CO2 (trends and var.) Leaf Area Index (Greening)

Ocean Carbon Inventory (trend) Air-Sea CO2 exchange (trends and var.)

C4MIP Umbrella

• Benchmark against 20th century• Constrains on processes driving climate-carbon feedback• Reduced uncertainty on

Climate-carbon cycle gain Compatible emissions Climate projections

I-LAMB

• 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 modelsAOGCMs

C4MIP models