Extreme High‐Temperature Events Over East Asia in 1.5°C and 2°C Warmer Futures: Analysis of NCAR CESM Low‐Warming Experiments

Extreme high‐temperature events have large socioeconomic and human health impacts. East Asia (EA) is a populous region, and it is crucial to assess the changes in extreme high‐temperature events in this region under different climate change scenarios. The Community Earth System Model low‐warming experiment data were applied to investigate the changes in the mean and extreme high temperatures in EA under 1.5°C and 2°C warming conditions above preindustrial levels. The results show that the magnitude of warming in EA is approximately 0.2°C higher than the global mean. Most populous subregions, including eastern China, the Korean Peninsula, and Japan, will see more intense, more frequent, and longer‐lasting extreme temperature events under 1.5°C and 2°C warming. The 0.5°C lower warming will help avoid 35%–46% of the increases in extreme high‐temperature events in terms of intensity, frequency, and duration in EA with maximal avoidance values (37%–49%) occurring in Mongolia. Thus, it is beneficial for EA to limit the warming target to 1.5°C rather than 2°C. Plain Language Summary Extreme heats continue to occur as global warming continues in the last several decades. These natural disasters can lead to illnesses and deaths of people and animals and great economic losses. The Paris Agreement called for limiting the global warming bellow 2°C and pursuing efforts to limit it to 1.5°C compared with preindustrial levels. We used a set of simulations to investigate the changes of the mean temperature and extreme heats in 1.5°C and 2°C warmer climates in East Asia and the benefits of limiting global warming to 1.5°C rather than 2°C. We find that the mean warming of East Asia is about 0.2°C higher than global mean. Most densely populated subregions, including eastern China, the Korean Peninsula, and Japan, will see larger extreme heats increase than the other subregions of East Asia. Compared with the 2°C warming climate, the increasing of extreme heats will be reduced over one third in the 1.5°C warming climate. Key Points Changes in the mean and extreme high temperatures over East Asia in response to warmings of 1.5°C and 2°C were quantified using the recently released NCAR CESM low‐warming experiment data Most densely populated subregions, including eastern China, the Korean Peninsula, and Japan, will see larger increases in extreme high‐temperature events than the other subregions of East Asia in terms of intensity, frequency, and duration under 1.5°C and 2°C warm