1. a Ministry of Education Key Laboratory for Earth System Modelling, Centre for Earth System Science , Tsinghua University , Beijing , 100084 , China
2. b State Key Lab of Remote Sensing Science, Jointly Sponsored by Institute of Remote Sensing Applications , Chinese Academy of Sciences, and Beijing Normal University , Beijing , 100101 , China
3. c Department of Environmental Science, Policy and Management , University of California , Berkeley , CA , 94720-3114 , USA