【中文介绍】

       随着全球变暖，高温热浪频发，已造成了严重的经济损失和人员伤亡。极端高温主要通过温度和湿度的变化直接影响人体健康。一般人体正常温度在36.8° ± 0.5°C，要求人体皮肤表层温度为35°C左右，从而使得体内外保持一定的温度梯度，有利于体内热量的散发；但如果环境又热又湿，超过了35°C的临界阈值，人体自身冷却机能就会减弱失效，甚至造成死亡。因此，深入认识未来全球变暖背景下中国地区湿热复合事件的变化及其影响具有十分重要的科学价值和意义。

       我们基于CMIP6计划的18个耦合模式逐日输出结果的研究指出，到本世纪末，中国地区日最高湿球温度显著增加，部分地区均有超过35°C的湿热复合事件发生，尤其在中国人口集中的东部和四川盆地地区，在SSP5-8.5高排放情景下尤为明显。估算指出，在SSP5-8.5情景下，中国有将近81%的人口暴露于极端湿热复合事件，即使在SSP1-2.6情景下，这个比例也达到了51%。进一步的研究指出，中国湿热人口暴露度的增加主要是由于气候变化的结果。因此，减少二氧化碳排放，探索绿色发展路径迫在眉睫。

  【英文介绍】

  Changes in heat stress due to climate change affect living and working conditions. A wet-bulb temperature (TW) of 35 °C is identified as the upper physiological limit for human survivability. On the basis of Coupled Model Intercomparison Project phase 6 model simulations, our evaluations show that the daily maximum TW is expected to significantly intensify throughout China and is likely to exceed this critical threshold in some regions by the end of this century, especially under the high emission scenario of the shared socioeconomic pathway (SSP)5-8.5. The most dangerous hazard from extreme heat-humidity events is concentrated around the most densely populated regions of eastern China as well as the Sichuan basin. Under SSP5-8.5, the significant increase of extreme heat-humidity days with a daily maximum TW exceeding 35 °C results in a large fractional population of approximately 81% being exposed to these extremes in China by the end of this century. This is true for different future warming scenarios, and a population fraction of up to 51% would also be exposed to such extremes even if early mitigation was conducted via SSP1-2.6. Our findings in this study thus have significant implications to ongoing considerations for climate-change policy in China.

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  【引用格式】       

  Chen, H.P., W.Y. He, J.Q. Sun, and L.F. Chen, 2022: Increases of extreme heat-humidity days endanger future populations living in China. Environmental Research Letters, 17, 064013. https://doi.org/10.1088/1748-9326/ac69fc