This article presents an overview of the history of international climate change policy over the last 30 years, divided into five periods. It examines the pre-1990 period, the period leading up to the adoption of the Climate Change Convention, the period of the Kyoto Protocol until US withdrawal, the period thereafter focusing on the entry into force of the Kyoto Protocol, and the post-2008 period that coincides with the financial crisis. For each period, it discusses the relevant science, actors, and coalitions, the agreements emerging in that period, and the key issues and the major trends. In doing so, it examines the evolving articulation of the leadership paradigm,which is the centerpiece of the discussion on how climate change should be addressed. The article shows (1) the increasing complexity of the definition of the climate change issue from an environmental to a development issue; (2) the inability of the developed countries to reduce their own emissions and raise funds commensurate with the nature of the problem and their initial commitments; (3) the increasing engagement of different social actors in the discussion and, in particular, the gradual use of market mechanisms in the regime; (4) the increasing search for alternative solutions within the formal negotiations-such as the identification of nationally appropriate mitigation actions for the developing world, reducing emissions from deforestation and forest degradation, and the use of geo-engineering solutions; and (5) the search for solutions outside the regime-the mobilization of sub-national policies on climate change, litigation, and markets on biofuels. © 2010 John Wiley & Sons, Ltd.