Abstract
The changes in the atmospheric chemical composition since the beginning of the industrial era have no equivalent throughout the Quaternary. All model simulations indicate that, without a significant decrease of the greenhouse gases emissions, climate is bound to change importantly during the years and decades to come. The precise forecast of these changes is made difficult both by the characteristics of natural systems which are not entirely predictable – as well as by our present and future socio-economic choices. To cite this article: H. Le Treut, C. R. Geoscience 335 (2003).