Abstract:This paper presents projections of regional climate change over China under carbon neutrality against the historical reference period (1995-2014), based on an ensemble of nine model simulations from the Coupled Model Intercomparison Project Phase 6 (CMIP6).The time of carbon neutrality globally is determined by the time of peak CO2 concentration under two scenarios, namely SSP1-1.9 and SSP1-2.6.The results are compared with what produced by the SSP2-4.5 scenario, in which carbon neutrality cannot be achieved.The respective times to reach carbon neutrality under the SSP1-1.9 and SSP1-2.6 scenarios are 2041 and 2063.Compared with the reference period, the areal-mean annual temperature in China increases by 1.22/1.58℃ under the SSP1-1.9/SSP1-2.6 scenarios, and the areal-mean annual precipitation increases by 7.1%/9.9%.The areal-mean annual temperature increases by 0.36℃ under the SSP1-2.6 (late carbon neutrality) in comparison to the SSP1-1.9 (early carbon neutrality), with the strongest warming located in southwestern China and on the Tibet Plateau.For precipitation, the areal-mean annual precipitation increases by 2.7% in the later carbon neutral period compared to the earlier carbon neutral period.The annual and summer precipitations increase significantly in northwestern China, with an increase greater than 8% occurring in Xinjiang.In winter, the region that has an increase of precipitation above 8% is located in the middle and lower reaches of the Yellow River.The warming under the SSP2-4.5 scenario is significantly stronger than that under the SSP1-2.6 scenario, with the regional mean temperature being about 0.61℃ higher.The largest warming is located in northwestern China, with an increase of greater than 0.8℃ in some parts of Xinjiang.The annual precipitation increases more significantly in northwestern China under the SSP2-4.5 scenario than that under the SSP1-2.6 scenario, with a maximum increase of above 10% in northwestern Inner Mongolia.The winter precipitation increases by more than 20% in some areas of Xinjiang, and decreases by more than 15% in Yunnan.The results of this study show that the presence or absence of carbon neutrality has a much greater impact on climate than the time (early or late) of carbon neutrality.