This study contends that international climate change negotiations over the past 15 years have served as a site for the development of a new international norm of state behavior vis-à-vis the climate system. Specifically, in the course of negotiating two multilateral treaties (the 1992 United Nations Framework Convention on Climate Change and the 1997 Kyoto Protocol) and debating about targets and timetables, trading and sinks, the climate change regime has created a collective understanding that members of the international community have a responsibility to mitigate the threat of climate change by reducing their greenhouse gas emissions. This norm has subsequently shaped how state and non-state actors define their interests on the issue of climate change, the strategies pursued to mitigate climate change, and has constrained the ability of some actors (e.g. the US) to determine the outcome of international negotiations. Focusing on the period 1988-1997, the study addresses two questions related to the emergence of an international climate change norm: 1) how do norms develop in world politics? and 2) what is the role of environmental non-governmental organizations (ENGOs) in that process?

The emergence of a new international norm is not unproblematic; for every norm that is created, there are a number of other norms that have not been taken up by states. Neorealists explain norm development in terms of material resources, neo-liberal institutionalists emphasize state interests, and constructivists focus on the work of "norm entrepreneurs," actors (typically non-state actors) who promote new standards of behavior by reshaping the way states frame problems. This study demonstrates that the pattern of norm development between 1988 and 1997 cannot adequately be explained in terms of the distribution of material resources or state interests. Although ENGOs tried to play the role of norm entrepreneur through their participation in international climate change negotiations, they had varying degrees of success in shaping the process of norm development during this period, suggesting the need to better understand the conditions under which norm entrepreneurs are likely to be successful.

Building on the constructivist approach, this study argues that international norms develop through a political process, involving state as well as non-state actors, where material forces influence, but do not determine, which norms will prevail. The process of norm emergence, as well as the ability of any given actor to shape that process, is contingent on the way issues are framed in world politics and the institutional setting in which norm development takes place. ENGOs were most influential in the process of norm development in the agenda-setting phase, during which time the frame they used to argue for significant emissions reductions resonated with the way state decision makers viewed the threat of climate change. Moreover, the institutional setting for global climate change politics during this period provided significant opportunities for environmentalists to participate in and shape the process of norm development. As states became more concerned with the economic implications of controlling greenhouse gas emissions, they were less willing to accept ENGO claims that climate change was a global crisis demanding more stringent standards of behavior. Additionally, ENGOs had greater difficulty finding political opportunities to shape norm development once the process moved to the arena of formal treaty negotiations, whereby states determined the rules of the game and had the final say.