Potential benefits of limiting global warming for the mitigation of temperature extremes in China

In this study, we attempt to quantify the potential impacts of two global warming levels (i.e., 1.5 °C and 2.0 °C) on extreme temperature indices across China. The CMIP6 dataset is first evaluated against the CN05.1 observation for the historical period of 1995–2014. Then, future spatiotemporal patterns of changes in extreme temperature at two global warming levels under two shared socio-economic pathway scenarios (SSP245 and SSP585) are further analyzed. Overall, China will experience more frequent and intense high temperature events, such as summer days (SU), tropical nights (TR), warm days (TX90p) and nights (TN90p). On the other hand, under the SSP585, the number of icing days and frost days is projected to decrease at two global warming levels, with the maximal days of decrease (exceeding 20 days) seen in the west of China. Our results suggest that limiting global warming to 1.5 °C rather than 2.0 °C is beneficial to reduce extreme temperature risks. As temperature increases to 1.5 °C and then 2.0 °C above preindustrial levels, the most extreme temperature indices are expected to increase proportionately more during the final 0.5° than during the first 1.5° across most regions of China. For some warm indices, such as the warmest day (TXx), summer days (SU), and warm days (TX90p), the largest incremental changes (from 1.5° to 2.0°) tend to be found in the southwest. Under the SSP585, the incremental changes are similar to the change in the SSP245, but smaller magnitude and spatial extent.

Junhong Guo, Xi Liang, Xiuquan Wang, Yurui Fan, Lvliu Liu