Jonathan L Bamber, University of Bristol, School of Geographical Sciences, Bristol, BS8, United Kingdom, Michael Oppenheimer, Princeton University, Woodrow Wilson School of Public and International Affairs, Princeton, NJ, United States, Robert E Kopp, Rutgers University New Brunswick, Institute of Earth, Ocean, and Atmospheric Sciences, New Brunswick, NJ, United States, Willy Aspinall, Organization Not Listed, Washington, DC, United States and Roger marvin Cooke, Resources for the Future, Washington, DC, United States