In IPSL-CM2, the IPSL thermodynamic sea ice model (L’Heveder 1999; Filiberti et al. 2001) has been implemented. This required some adjustment in the coupling procedure. In particular, in this IPSL-CM2 version, the sea ice model computed sea ice albedo, and other surface parameters (Braconnot et al. 2000). The derivative of the fluxes to temperature was also provided to the sea ice model to insure the stability of the coupling over sea ice, following the detailed stability analysis of Dufresne et al. (1996). A transient experiment where the CO2 incresaes by 1% every year was perfomed (Batrtelet et al., 1998). This version of the model yields to interesting results about the analysis of the response of the climate to changes in insolation (Braconnot and Marti 2003; Khodri et al. 2005) and participate to the CMIP-2 and PMIP-1 projects.

This model has been used to quantify the climate-carbon feedback, first off-line (Friedlingstein et al. 2001) and then on-line (Dufresne et al. 2002). This coupled climate-carbon model IPSL-CM2-C has been used to perform the first climate simulations (present and future) with an interactive carbon cycle.