The Center for Applied Mathematics (CMA) develops an original scientific approach by applying its fundamental scientific skills in modelling and the mathematics of control and decision-making to tackle the issue of decarbonisation of complex systems on a multi-scale basis, covering both time and space. This original stance, which fundamental mathematics and climate issues, is the culmination of a visionnary scientific strategy that was initiated some twenty years ago. Energy issues associated with climate change and globalisation provided the opportunity for a thematic renewal in the mathematics of decision making, a field in which the laboratory has a great deal of expertise, notably with the recent development of data mining.