In this article, a framework is suggested to deal with the analysis of global environmental risk governance. Climate Change is taken as a particular form of contemporary environmental risk, and mobilised to refine and characterize some salient aspects of new governance challenges. A governance framework is elaborated along three basic features: (1) a close relationship with science, (2) an in-built reflexivity, and (3) forms of governmentality. The UNFCCC-centered system is then assessed according to this three-tier framework. While the two-first requisites are largely met, the analysis of governmentality points to some institutional weak spots.