Projection of temperature and precipitation changes over China under global warming of 1.5 and 2℃

Based on the outputs of CMIP5 under three Representative Concentration Pathways (RCPs) scenarios, temperature and precipitation changes over China in the context of global warming of 1.5 and 2℃ are projected and their differences are further compared. The results show that in the context of global warming of 1.5℃ (relative to the reference period 1986-2005, the same hereafter), amplitudes of annual and seasonal mean temperature warming enhance towards high-latitude region especially in the Qinghai-Tibet Plateau. Annual mean air temperature over China will increase 1.83, 1.75 and 1.88℃ respectively under the RCP2.6, RCP4.5 and RCP8.5 scenarios with largest increases in the winter. Except for South China and Southwest China, most areas of China will experience more precipitation but the increase will be different between various seasons. The enhancement in annual mean precipitation over China ranges from 2.82% to 5.03%, and the largest increase occurs in the winter. The spatial distributions of temperature change are similar under the conditions of 1.5 and 2℃ global warming. When global warming is 2℃, annual temperature over China will increase 2.49 and 2.54℃ under the RCP4.5 and RCP8.5 scenarios, respectively. Annual precipitation will increase in most areas of China, whereas there are obvious seasonal differences in Northwest China and the middle and lower reaches of Yangtze River. Compared with the situation under the 1.5℃ threshold, more temperature and precipitation increases can be expected under the 2℃ threshold. The most significant increases in temperature will occur in Northeast China, Northwest China and the Qinghai-Tibet Plateau, while significant precipitation changes will occur in Northeast China, North China, the Qinghai-Tibet Plateau and South China.