Impacts of Stabilization Pathways on Extreme Temperature in China between 1.5° and 2°C Warming

The Paris Agreement aims to keep global average temperature rise well below 2℃ and better to limit the temperature increase no more than 1.5℃ above pre-industrial level by the end of this century. However, the influence of 0.5℃ difference of global warming on the regional climate in China remains poorly understood under 1.5 and 2℃ stabilization pathways, especially the extreme temperature events which causes greater threatens on health, society and economy.

Using the Community Earth System Model low-warming experiment data (Sanderson, 2017), we investigated the differences in extreme indices associated with temperature in China between 1.5℃ and 2℃ warming scenarios, and analyzed the potential driving mechanisms. Our results show that the increase in mean temperature of China is amplified by 0.6℃ under the 2℃ warming compared with the 1.5℃ case. The 0.5℃ more warming levels up the extreme high temperature remarkably over arid/semi-arid regions in summer and Tibetan Plateau in winter, indicating an intensification of extreme hot events. More frequent and longer lasting extreme temperature events mainly occur in Tibetan Plateau, Northeastern China and arid/semi-arid regions contributed by the 0.5℃ warming. Enhanced extreme temperature events can be attributed to lower soil moisture, vegetation coverage and specific heat in a warmer world, as well as snow cover and water vapor feedbacks. Therefore, the 1.5℃ target can significantly help to reduce the risks of extreme temperature events in China.

Reference: Sanderson, B. M., Xu, Y., Tebaldi, C., Wehner, M., O'Neill, B., & Jahn, A., et al. (2017). Community climate simulations to assess avoided impacts in 1.5 and 2 °c futures. Earth System Dynamics, 8(3), 1-33.