1. Department of Environmental Sciences, University of Basel, 4054 Basel, Switzerland.
2. Department of History, Princeton University, Princeton, NJ 08544, USA.
3. Department of Geosciences, University of Massachusetts, Amherst, MA 01003, USA.
4. Institute of Global Environmental Change, Xi’an Jiatong University, Xi’an 710054, China.
5. State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences, Xi’an 710061, China.
6. Key Laboratory of Karst Dynamics, MLR, Institute of Karst Geology, CAGS, Guilin 541004, China.
7. Department of Earth and Environmental Sciences, University of Minnesota, Minneapolis, MN 55455, USA.
8. Climate and Environmental Physics, Physics Institute, University of Bern, 3012 Bern, Switzerland.
9. Oeschger Centre for Climate Change Research, University of Bern, 3012 Bern, Switzerland.
10. Department of Archaeology, University of Reading, Reading RG6 6AB, UK.
11. Institute of Geological Sciences, University of Bern, 3012 Bern, Switzerland.