1. Emmett Interdisciplinary Program in Environment and Resources, Stanford University, Stanford, California 94305, United States
2. Center on Food Security and the Environment, Stanford University, Stanford, California 94305, United States
3. Department of Earth System Science, Stanford University, Stanford, California 94305, United States
4. Goldman School of Public Policy, UC Berkeley, Berkeley, California 94720, United States
5. Global Policy School, UC San Diego, San Diego, California 92093, United States
6. National Bureau of Economic Research, Cambridge, Massachusetts 02138, United States