资源环境科技发展态势分析平台

The additional 0.5 degrees C warming from 1.5 to 2 degrees C global target has a significant impact on the occurrence of extreme temperature events. While the arid and semi-arid areas (ASA) and humid areas (HA) present different response characteristics to the additional global mean 0.5 degrees C warming due to their differences in thermal properties. In this study, both the stabilized and transient 1.5 degrees C (2 degrees C) global warming scenarios projected by the Community Earth System Model (CESM) are used to compare the extreme temperature responses between the ASA and HA to the 2 and 1.5 degrees C global warming targets over East-central Asia. The results indicate that cold fixed-threshold indices (frost days [FD] and icing days [ID]) will decrease more rapidly in ASA, by approximately 10 days (1.5 degrees C) and 15days (2 degrees C) compared to the historical period, respectively. Warm fixed-threshold indices (summer days [SU] and tropical nights [TR]) will become more common in HA, especially southeast of China. Under 1.5 degrees C target, the increase of intensity indices is equal to the average temperature warming response (1.5 degrees C), while the additional 0.5 degrees C warming makes the response of intensity indices much greater than 0.5 degrees C. Under 0.5 degrees C warmer world, the daily temperature range (DTR) will experience a 0.5 degrees C increase in most HA and a 0.2-0.5 degrees C decrease in ASA during winter. As a whole, the additional 0.5 degrees C warming has an amplified effect and the 1.5 degrees C global warming target could reduce the extreme temperature events significantly over East-central Asia.