Climate-Carbon Interactions in the Current Century (4C) addresses the crucial knowledge gap in the climate sensitivity to carbon dioxide emissions, by reducing the uncertainty in our quantitative understanding of carbon-climate interactions and feedbacks. This will be achieved through innovative integration of models and observations, providing new constraints on modelled carbon-climate interactions and climate projections, and supporting Intergovernmental Panel on Climate Change (IPCC) assessments and policy objectives.

IPSL contributes to several objectives of 4C, in particular in relation do methodologies for initialising decadal prediction and short-term predictions of the carbon cycle.

The 4C project is further described on this page.