Detection and attribution for land surface air temperature warming in China based on a perfect model selection analysis of optimal fingerprint strategy

Observations show that the warming trends of annual and seasonal surface air temperature (SAT) in China have been about 0.15 ~ 0.31 ℃/10a in China since the 1950s. The warming trend is higher in winter and spring than in summer and fall, and higher in the northern region than in the southern region. Additionally, the warming trend is higher in the western part of China than in the eastern part, except for spring. These variations have been well simulated by the recent CMIP6 models. Using a perfect model method, the all-forcing (ALL) + anthropogenic aerosol forcing only (AER) + natural forcing only (NAT) strategy has been applied to the detection and attribution of SAT trends in China since 1951. It is found that GHG (greenhouse gas forcing only) is detected robustly in all seasons and regions except winter in eastern China, contributing to a warming of 0.21 ~ 0.36 ℃/10a. This indicates that the greenhouse gas from human activities is the primary factor causing the warming in mainland China over the past 70 years. The contribution of the AER has only been detectable in the variations in summer of the whole mainland China and western China with neglectable effect since the late twentieth century. The NAT forcing can also be neglected.