Jonathan Pershing '76 U.S. Deputy Special Envoy for Climate Change, State Department, was head of the United States delegation at the United Nations Climate Change Conference in Copenhagen, Denmark in December 2009.

From the State Department's website:
Dr. Pershing has more than 20 years of domestic and international experience in climate change science, technology, and policy. Prior to joining the State Department, Dr. Pershing served as Director of the Climate, Energy and Pollution Program at the World Resources Institute (WRI), a non-partisan environmental think tank in Washington, D.C. He also directed the Environment Program at the International Energy Agency in Paris, and spent nearly a decade in the State Department as a senior climate official in the 1990s. Dr. Pershing is widely recognized for his work on international climate change architecture, including the design of a post-Kyoto Protocol climate change agreement. He has served on multinational advisory boards supporting the development of both U.S. domestic and international climate policy.