This PhD project explores the political influence of four sets of non-governmental actors upon the international politics of global warming. The forms of influence attributable to Working Group 1 of the Intergovernmental Panel on Climate Change (the body set up to advise governments on the science of climate change), the mass media's coverage of global warming, and the political involvement of both the fossil fuel lobbies and environmental groups in the policy debate on climate change, are understood via use of literatures on the dimensions of power appropriate to understanding the significance of non-state actors. The project stems from a widely acknowledged absence of a detailed understanding of the role of non-governmental organisations in international environmental politics, which extends to the international politics of global warming. The influence of each group of actors is conceptualised in different ways, so that the forms of power used to describe the various groups are not compared. Rather, the aim of the thesis is to assess what a less state-centred reading of the international politics of global warming, derived from a discussion of the role of the above actors, has to offer existing explanations. The analysis of these groups of actors sheds light on different aspects of the way the issue of climate change has been addressed at the international level. The conclusions drawn about the influence of these actors are used to critique the popular use of Regime accounts in international environmental politics that focus upon the process of institutional bargaining between states, which are argued to provide an inadequate basis for explanation of the global politics of climate change.