1. Potsdam Institute for Climate Impact Research, 14412 Potsdam, Germany.
2. Physics Institute, Potsdam University, 14476 Potsdam, Germany.
3. Department of Global Ecology, Carnegie Institution for Science, Stanford, CA 94305, USA.
4. BRIDGE (Bristol Research Initiative for the Dynamic Global Environment), School of Geographical Sciences, University of Bristol, Bristol BS8 1SS, UK.
5. Department of Earth Sciences, University of California, Riverside, Riverside, CA 92521, USA.