Detectable Impacts of the Past Half‐Degree Global Warming on Summertime Hot Extremes in China

Abstract

AbstractAvoided risks in a 1.5°C warmer world as opposed to a 2°C one become urgent to be assessed after the Paris Agreement, especially at regional scales. To provide an observable analog, this study quantified detectable impacts of the past 0.5°C global warming on summertime hot extremes in China. The half‐degree global warming has preferentially facilitated the emergence and prevalence of complex hot extremes (sequential hot day‐night), which experienced a twofold‐fourfold increase in their frequency in Southeast China, lower reaches of the Yangtze River, and northern China, along with a doubling to tripling of duration and intensity. The past global warming of 0.5°C further exacerbated the vulnerability of above hot spots by exposing them to drastically augmented (over 300%) excess heat accumulated during the severest complex events. These observation‐based solid evidences imply that a 0.5°C reduction in future global warming does matter for China to avoid excessively escalated risks of complex hot extremes.