Temperature and Precipitation Changes over China under a 1.5℃ Global Warming Scenario Based on CMIP5 Models

To better understand the climate changes over China associated with a 1.5℃ global warming world relative to the pre-industrial levels, the authors present an analysis based on numerical experiments undertaken using 39 Coupled Model Intercomparison Project Phase 5 (CMIP5) global climate models. The results indicate that a global warming of 1.5℃ will occur in the median year 2034 for the representative concentration pathway (RCP) 2.6, 2033 for RCP4.5, and 2029 for RCP8.5. Under a 1.5℃ global warming world, annual and seasonal temperatures are projected to increase by an average of 1.8℃ and 1.6-2.1℃, respectively, with the strongest warming occurring in winter. Generally, the warming strengthens from south to north, and an amplification occurs in the Tibetan Plateau. Change signals of annual and seasonal temperatures exceed the local natural internal variability over the entire country, and the corresponding signal-to-noise ratios average 3.4 and 1.6-2.7, respectively. Annual and seasonal precipitation is expected to increase in northern China and decrease in southern China. Annual and seasonal precipitation averaged over the country increases by 1.4% and 0.1%-5.1%, respectively, with the greatest increase occurring in winter. On the whole, changes in annual and seasonal precipitation do not fall outside the local natural internal variability, and the signal-to-noise ratios averaged over the country are 0.1 and 0.01-0.2, respectively. Greater inter-model uncertainty occurs in the projection of changes in precipitation than that of changes in temperature, and the same holds for the seasonal projections.