Contribution of human influence to increased daily precipitation extremes over China

This study provides an estimate of the human influence on increases in daily precipitation extremes over China using data sets from multiple coupled climate models participating in the Coupled Model Intercomparison Project Phase 5. The effects of human forcings can be detected in the observed changes of daily precipitation extremes, but the effects of external natural forcings as well as the aerosols are not detected using the optimal fingerprint methods. Estimation showed that human influence has increased daily precipitation extremes by approximately 13% (1% to 25% for 90% confidence interval) on average over China in recent decades. With further warming, human influences on precipitation extremes would be amplified. For a temperature increase of 1.5 degrees C with respect to the preindustrial time, the occurrence probability of severe extremes is doubled, and approximately 51% of these events occurring over China are attributable to human influences. This fraction increases with temperature. Furthermore, the contributions of human influences are much stronger for the high-percentile extremes, and the highest sensitivity of the changes in daily precipitation extremes due to human influences is observed in the region of the Tibetan Plateau in the southwest of China.