Extreme precipitation over East Asia under 1.5 °C and 2 °C global warming targets: a comparison of stabilized and overshoot projections

Abstract

Highly populated East Asia is vulnerable to extreme precipitation. Here, we use Community Earth System Model low-warming simulations to examine how extreme precipitation events may change in East Asia under the Paris Agreement global warming targets. The frequency and intensity of extreme precipitation will increase markedly over East Asia in the warmer climates. Limiting end-of-century warming to 1.5 °C, in comparison with 2 °C, will reduce the risks of extreme precipitation frequency and intensity in East Asia by 26%–31%, with the greatest reductions (38%–54%) in Japan. A brief overshoot of the 1.5 °C target would affect Mongolia, the Korean Peninsula and Japan from the aspects of regional average. More than 25% of the increase in the frequency and intensity of extreme precipitation in these regions can be avoided during the end of the 21st century (2081–2100) if there is no temperature overshoot, according to the best estimate. Vertical moisture advection is the main contributor to changes in precipitation-minus-evaporation in East Asia in the warmer climates. The increased low-level specific humidity and cyclonic circulation changes are the dominant thermodynamic and dynamical processes that contribute to the increase of precipitation over South China and Japan. Our work suggests that limiting warming to 1.5 °C without overshoot is beneficial to minimizing the impacts associated with precipitation extremes across East Asia.