Calls for new forms of governance are a response to the political, economic and social challenges of globalisation and the increasing complexity of the international agenda. Global environmental governance has become a leitmotif of contemporary environmental politics, something to be theorised as an idea and to be realised in material form. It is constructed and contested, a political artefact which inscribes a parabola of normative and material possibilities on the axes of world politics-states and markets, the local and the global.1 A precise definition remains elusive. It is variously presented as a desideratum; as a useful shorthand to describe changes in contemporary international political practice; as a metaphor for ‘world collective life’; and as a Trojan horse for neoliberalism and green corporatism. These images of global environmental governance co-exist at the same time as they are in contest. The consequences have been theoretical confusion and institutional uncertainty.