1. State Key Joint Laboratory of Environment Simulation and Pollution Control (SKLESPC) and School of Environment, Tsinghua University, Beijing 10084, P. R. China
2. Ministry of Education Key Laboratory for Earth System Modeling and Department of Earth System, Science Tsinghua University, Beijing 100084, P. R. China
3. School of Economics, Hitotsubashi University, Tokyo 186-8601, Japan