Additional risk in extreme precipitation in China from 1.5 °C to 2.0 °C global warming levels

To avoid dangerous climate change impact, the Paris Agreement sets out two ambitious goals: to limit the global warming to be well below 2 °C and to pursue effort for the global warming to be below 1.5 °C above the pre-industrial level. As climate change risks may be region-dependent, changes in magnitude and probability of extreme precipitation over China are investigated under those two global warming levels based on simulations from the Coupled Model Inter-Comparison Projects Phase 5. The focus is on the added changes due to the additional half a degree warming from 1.5 °C to 2 °C. Results show that regional average changes in the magnitude do not depend on the return periods with a relative increase around 7% and 11% at the 1.5 °C and 2 °C global warming levels, respectively. The additional half a degree global warming adds an additional increase in the magnitude by nearly 4%. The regional average changes in term of occurrence probabilities show dependence on the return periods, with rarer events (longer return periods) having larger increase of risk. For the 100-year historical event, the probability is projected to increase by a factor of 1.6 and 2.4 at the 1.5 °C and 2 °C global warming levels, respectively. The projected changes in extreme precipitation are independent of the RCP scenarios.