The science of climate change structures the economics: risk of major damage and a global response must be at the core of an analysis of policy. History and wealth structure the ethics. The economics of climate change must, therefore, point to effective, efficient, and ethical, as well as collaborative, policy responses. This lecture will follow this analysis and describe a possible global deal or framework and how it might be built. Lord Stern is I.G. Patel Professor of Economics and Government and heads a new India Observatory within the London School of Economics Asia Research Centre. He has been an adviser to the U.K. government on the economics of climate change and development, reporting to the prime minister from 2003-2007; author of the Stern Review Report on the Economics of Climate Change; and the head of the government economic service. From 2003-2005, he was second permanent secretary to the Treasury and from 2004-2005, director of policy and research for the prime minister's commission for Africa. He has also served as World Bank chief economist and senior vice president, development economics. In addition he has been the chief economist and special counsellor to the president at the European Bank for Reconstruction and Development. His most recent book on development, Growth and Empowerment: Making Development Happen, was published in April 2005. The Stern Review Report on the Economics of Climate Change was published in October 2006 (http://www.sternreview.org.uk), and in printed form by Cambridge University Press in January 2007. A Walter E. Edge Lecture, cosponsored by the Program in Science, Technology, and Environmental Policy and the Princeton Environmental Institute