Putting the Earth System in a numerical box? The evolution from climate modeling toward global change

Since the 1980s, climate modeling has undergone major transformations. The most prominent of these are the proliferation of coupled models and the integration within models of a growing number of environments and feedbacks. Climate modelers now increasingly define their object in terms of an “Earth System” instead of a “climate system”. In addition to this proliferation of coupled models, the carbon cycle and its feedback on various environments, from the atmosphere to the ocean and to vegetation cover, has become a prominent component of climate modeling. These transformations derive from the IPCC’s overall methodology, and are closely bound up with both a heightened awareness of the risks of climate change, as well as an issue of crucial political importance: the question of socio-economic/climate integration. In this article I follow, from a roughly chronological point of view, the major steps of this evolution and its links with the evolution of the political agenda. What can we say about this seemingly irreversible tendency to incorporate everything into models and to take account of everything that influences the Earth’s climate? Could we correlate it to the strong tendency toward globalization? How is the notion of climate itself affected? These are the main questions of the paper.