1. W. C. Sailor and B. van der Zwaan are at the Center for International Security and Cooperation, Stanford University, Stanford, CA 94305-6165, USA.
2. D. Bodansky is professor emeritus, Department of Physics, University of Washington, Seattle, WA 98195, USA.
3. C. Braun is with Altos Management Partners, Los Altos Hills, CA 94022, USA.
4. S. Fetter is at the School of Public Affairs, University of Maryland, College Park, MD 20742-1821, USA.
5. B. van der Zwaan is also at the Institute for Environmental Studies, Vrije Universiteit, Amsterdam, The Netherlands.