Asian climate warming since 1901: observation and simulation

Land surface air temperature in Asia has been increasing significantly since the 1950s. However, current understanding of Asian warming since 1901 in terms of observations and simulations is still poor. Based on a newly developed observation dataset with 2658 stations and Coupled Model Intercomparison Project Phase 5/6 (CMIP5/6) output data, we analyze changes in mean (Tmean), maximum (Tmax), and minimum (Tmin) temperature, and diurnal temperature range (DTR) over Asia during 1901-2100. Annual mean land surface air temperature over Asia increased significantly, and Tmean, Tmax, and Tmin increased by 1.81, 1.47, and 2.15 degrees C during 1901-2020, respectively. The Tmin warming rate is about 1.5x that of Tmax, resulting in a decline of Asian DTR by 0.68 degrees C since 1901. We also found that Asia has experienced more substantial warming than the global case and the Northern Hemisphere, and the decline in DTR is more substantial in Asia. Spatially, Asia exhibits a general warming trend with a gradual increase in spatial warming from low to high latitudes, and the effect of high-latitude warming has gradually strengthened since the 2000s. Seasonally, Asian warming in the cold season is stronger than in the warm season. Furthermore, CMIP5/6 can capture the Asian warming in the historical period 1901-2020. However, it underestimated Tmin and overestimated Tmax, contributing to their poor performance in simulating the historical change of DTR. Under Shared Socioeconomic Pathway (SSP) 2-4.5, Asian Tmean, Tmax, and Tmin are projected to increase by 3.5, 3.4, and 3.7 degrees C century-1 during 2021-2100, respectively. The Asian warming rate under SSP5-8.5 is about 2x that of SSP2-4.5.