1. Center for Industrial Ecology, Yale University, New Haven, Connecticut 06511, United States
2. Yale School of the Environment, Yale University, New Haven, Connecticut 06511, United States
3. International Institute for Applied Systems Analysis (IIASA), A-2361 Laxenburg, Austria
4. Industrial Ecology Program, Department of Energy and Process Engineering, Norwegian University of Science and Technology (NTNU), 7495 Trondheim, Norway