Climate change has become increasingly important in both the media and politics over the past decades. Considered as radically global, because greenhouse gas emissions in one part of the world have an impact on the whole planet, the climate risk is impossible to detect or to combat without the help of the natural, economic and social sciences. Climate change thus poses fundamental questions concerning the relationship between different scales of human action, and the organization of scientific expertise in the governance of environmental problems. In this thesis, we ask how climate change has emerged as a public problem, and how specific interpretations of the problem have become dominant in four different contexts: in the global arena of UN negotiations, at the European level, and in France and Germany. We combine tools and methods from the sociology of public problems, from political sciences, and Science and Technology Studies, in order to shed light on how these interpretations emerge and circulate, and how they are promoted and imposed by different actors.
