This seminar examines the legal, scientific, political, economic, and organizational issues associated with the creation of international environmental regimes. The principal focus is on the issue of climate change, with a focus on the current regime(s) and the post-Kyoto negotiations, now underway. The course also addresses the Montreal Protocol for Ozone Depleting Substances, the International Convention for Regulation of Whaling, and the U.N. Convention on Straddling Fish Stocks and Highly Migratory Fish Stocks. It examines the interaction between law, science, and economics in shaping the choice of treaty instrument and the implementation and evolution of environmental regimes. The course also looks closely at the structure and performance of environmental markets as solutions to global commons problems. Finally, it considers the evolving meanings in an international context of concepts such as sustainable development, common heritage of mankind, and common but differentiated responsibilities of nations.