Climate change in the twenty-first century over China: projections by an RCM and the driving GCM

A regional climate model (RegCM4) is used to project climate change over China in the twenty-first century under the RCP4.5 and RCP8.5 pathways. The driving GCM is CSIRO Mk3.6.0 (hereafter referred to simply as CSIRO), and the simulation (hereafter referred to as CdR) is run at a grid spacing of 25 km. The focus of the present paper is on the changes in mean surface air temperature and precipitation in December-January-February (DJF) and June-July-August (JJA) over China. Validation of the model performances is provided first, followed by a comparison of future changes projected by CSIRO and CdR. Substantial warming in the future is simulated by both models, being more pronounced in DJF compared to JJA , and under RCP8.5 compared to RCP4.5. The warming shows different spatial patterns and, to a less extent, magnitude between CSIRO and CdR. Precipitation change shows a general increase in DJF and a mixture of increase and decrease in JJA. Substantial differences between the two models are found in for precipitation change in JJA. The paper further emphasizes the uncertainties in climate change projection over the region.