1. Potsdam Institute for Climate Impact Research, 14473 Potsdam, Germany.
2. Center for International Development, Harvard University, Cambridge, MA 02138, USA.
3. Department of Environmental Sciences, Wageningen University, 6700 AA Wageningen, Netherlands.
4. Department of Earth Sciences, University of Bristol, BS8 1RJ Bristol, UK.
5. School of Geography and Environment, University of Oxford, OX1 3TB Oxford, UK.