The nations of the world confront a tremendous challenge in designing and implementing an international policy response to the threat of global climate change that is scientifically sound, economically rational, and politically pragmatic. It is broadly acknowledged that the relatively wealthy, developed countries are responsible for a majority of the anthropogenic greenhouse gases (GHGs) that have already accumulated in the atmosphere, but developing countries will emit more GHGs over this century than the currently industrialized nations if no efforts are taken to alter their course of development. The architecture of a robust international climate change policy will need to take into account the many dimensions and consequences of this issue with respect to the environment, the economy, energy, and development.

The Kyoto Protocol—which builds directly on the foundation laid by the United Nations Framework Convention on Climate Change (UNFCCC)—represented a first step toward addressing this long-term, global problem. Now, the international policy community needs to identify the next step, both in terms of setting sensible climate-related goals and in designing effective policies to achieve those goals. The Harvard Project on International Climate Agreements aims to aid and inform that process through a diverse set of research initiatives in Europe, the United States, China, India, Japan, and Australia. This book is a product of that research.

Drawing upon lessons from experience with the Kyoto Protocol (Aldy and Stavins, Chapter 1; and Schmalensee) and insights from economics, political science, international relations, legal scholarship, and other disciplines, the contributors to this volume have set forth a range of ideas about how best to construct a post-2012 international climate change policy regime.