Increased population exposure to extreme droughts in China due to 0.5 °C of additional warming

Abstract

Drought, one of the major natural disasters in China, generally causes the largest socioeconomic loss each year and also has severe human health impacts. It is thus crucial to assess the changes in droughts in this region under different climate change scenarios. This study examines the impacts of stabilized 1.5 °C and 2.0 °C warming at the end of the 21st century on drought events in China by using a set of coupled Earth system model low-warming simulations. If warming is limited to 1.5 °C or 2.0 °C, these simulations suggest that droughts will become more frequent and more intense compared to the present day, particularly over the northern regions of China. In comparison to the 1.5 °C warmer future, the 0.5 °C additional warming in the 2.0 °C warmer future will account for approximately 9% of the increase in the drought occurrence in China and approximately 8% of extreme droughts, while there are relatively small responses for moderate and severe droughts. Consequently, the additional warming would lead to significantly higher drought impacts, and the population exposure to the extreme droughts is projected to increase by approximately 17%, although the exposure to moderate droughts decreases. Therefore, our results suggest that the mitigation of anthropogenic warming by 0.5 °C to achieve the 1.5 °C warmer climate instead of the 2.0 °C climate may have benefits for future drought risks and impacts.

Keywords

• drought
• population exposure
• 1.5 ºC
• 2.0 ºC
• China