由中山大学刘小平、罗明等学者主导的最新研究表明，在高排放场景下，到21世纪末全球平均每个高温日的极端高温时长可能额外增加4小时[1]。该研究利用1981年至2023年的全球小时尺度气温数据进行分析，采用小时尺度而非传统日尺度的评估方法，能够更准确地捕捉高温暴露情况[1]。相关论文已于北京时间8月10日在《自然-气候变化》期刊上线[1]。
研究数据显示，在过去数十年中，全球陆地区域每年夏季平均经历约269小时的极端高温[1]，且1981年至2023年间，平均每十年极端高温时长增加62小时[1]。值得注意的是，有28%的极端高温时长事件发生在不符合日尺度极端高温标准的日子里，这说明小时尺度评估能够识别传统方法遗漏的高温风险[1]。全球范围内，超过80%的陆地地区显示出高温暴露增加的趋势[1]。
从地区分布来看，中等和低收入国家承受着尤为沉重的高温负担，占当前和预测高温暴露总量的3/4以上[1]。研究团队指出，这一发现对高温风险管理和公共卫生规划具有重要意义[1]。
Researchers led by Liu Xiaoping and Luo Ming from Sun Yat-sen University have found that under high-emission scenarios, the duration of extreme heat exposure during each hot day globally could increase by an additional four hours by the end of the 21st century, specifically during the 2070–2099 period compared to current levels [1]. The study analyzed hourly-scale temperature data spanning from 1981 to 2023, employing hour-by-hour measurement rather than daily aggregation to more accurately capture heat exposure patterns, findings that hold significant implications for heat risk management and public health planning [1].
The research reveals that extreme heat duration has been expanding at a rate of 62 additional hours per decade over the 1981–2023 period [1]. Currently, land regions worldwide experience approximately 269 hours of extreme heat annually during summer months [1]. Notably, 28% of extreme heat events occur on days that would not be classified as extremely hot using traditional daily-scale indicators [1]. Geographic disparities remain stark, with over 80% of global land showing increased heat exposure [1], and middle- and low-income countries accounting for more than three-quarters of both current and projected heat exposure [1]. The findings were published in Nature Climate Change and went online on August 10 [1].