1 School of Geography and Planning, Sun Yat-sen University, Guangzhou 510006, China.
2 Department of Geographical Sciences, University of Maryland, College Park MD 20742, USA.
3 Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China. Electronic address: fangcl@igsnrr.ac.cn.
4 Department of Earth System Science, Tsinghua University, Beijing 100084, China.
5 Integrated Research on Energy, Environment and Society (IREES), Energy and Sustainability Research Institute Groningen (ESRIG), University of Groningen, Groningen, AG 9747, the Netherlands. Electronic address: hubacek@umd.edu.
6 School of Geography and Planning, Sun Yat-sen University, Guangzhou 510006, China. Electronic address: liuxp3@mail.sysu.edu.cn.