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Study warns of longer extreme heat periods by century's end_我的网站

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A | (ECNS) -- Hot days worldwide could experience around four additional hours of extreme heat by the end of the 21st century under a high-emissions scenario, according to a study led by Chinese researchers. Published in Nature Climate Change, the study found that traditional daily temperature indicators may overlook shorter periods of extreme heat, while hourly temperature analysis can provide a more detailed picture of heat exposure and associated risks. Researchers from Sun Yat-sen University and other institutions analyzed global hourly temperature data from 1981 to 2023, combining observational records with climate model projections to assess how extreme heat exposure could change in the future. The research team found that the duration of extreme heat increased by 62 hours per decade over the study period. Around 28% of extreme heat events occurred on days that would not have been classified as hot days based on conventional daily temperature indicators. Under a high-emissions scenario known as SSP5-8.5, the researchers projected that between 2070 and 2099, each hot day could experience around four additional hours of extreme heat compared with the 2001-2023 period. Days not classified as hot could also see increased periods of extreme heat. The study also found that low- and middle-income countries account for a disproportionately large share of both current and projected extreme heat exposure. Younger generations in low-income countries are expected to experience the greatest increase in lifetime exposure. Researchers said the findings could help improve heat-warning systems, strengthen assessments of health risks and support climate adaptation efforts. (By Helen Mo, intern Liu Shuangjing) 。