Double increase in precipitation extremes across China in a 1.5 °C/2.0 °C warmer climate

Abstract

Paris Agreement's 1.5 °C or 2.0 °C global warming targets call for human concerns on warming climate on human society and environment in general. Here we analyzed spatiotemporal patterns and related impacts of precipitation extremes on human society across China using NEX-GDDP (NASA Earth Exchange Global Daily Downscaled Projections) dataset. We found increasing trends of almost all extreme precipitation indices except consecutive dry duration (CDD). Additional 0.5 °C warmer climate from 1.5 °C to 2.0 °C global warming targets can double increase of extreme precipitation indices. Specifically, the increase of Rx5day (Max 5-day precipitation amount) is from 3.98% to 7.63%, the increase of R95pTOT (precipitation in very wet days) is from 19.41% to 34.42% and the increase of PRCPTOT (annual total wet-day precipitation) is from 3.89% to 8.23%, showing that additional 0.5 °C warmer climate can potentially increase flood risks across China. While, we also found regional differences in responses of extreme precipitation to warming climate. Extreme precipitation in the Qinghai Tibet Plateau, the Western Arid and semiarid zone and in the lower Yangtze River basin is in higher sensitivity to warming climate. Constraint of temperature increase of below 1.5 °C but not 2.0 °C will avoid 4.34% to 73.96% impacts of extreme precipitation on human society. It is particularly important for China since that more than half of territory of China is under exposure to high flood and drought disasters.