Emory University, Princeton University - Princeton University, affiliation not provided to SSRN, International Institute for Applied Systems Analysis (IIASA), Independent, Tsinghua University - Department of Earth System Science, affiliation not provided to SSRN, Princeton University - Princeton University, Emory University, affiliation not provided to SSRN, Paris School of Economics, affiliation not provided to SSRN, affiliation not provided to SSRN, International Institute for Applied Systems Analysis (IIASA), - Center for Global Sustainability, UNDP, Princeton University - Andlinger Center for Energy and the Environment and University of Texas at Austin