School of Hydrology and Water Resources, Nanjing University of Information Science and Technology, Nanjing 210044, Jiangsu, China.
School of Hydrology and Water Resources, Nanjing University of Information Science and Technology, Nanjing 210044, Jiangsu, China.
Sci Total Environ. 2021 Jun 10;772:145004. doi: 10.1016/j.scitotenv.2021.145004. Epub 2021 Feb 3.
Attributing the changes in the population exposure to global compound hot extremes, which combine daytime-nighttime hot extremes with more severe impacts, is essential for climate change adaptation. Based on daily temperature data from the Coupled Model Intercomparison Project phase 6 (CMIP6) and population data, we estimate the changes in population exposure for two future periods under three scenarios of emission and socio-economic development at global and continental scales, and assess the contributions from climate and population changes. We find that the spatial patterns of exposure to compound hot extremes are similar for different periods and scenarios, and regions with high exposure are mainly located over East Asia, South Asia, Europe, and parts of eastern USA and Africa. The exposure shows an increase from baseline (1980-2014) to mid- and late 21st century periods (2021-2055 and 2056-2090) in most regions worldwide. Under the business-as-usual scenario (SSP2-4.5), the global exposure increases by ~19-fold during the late 21st century, and Africa shows the largest increase while Europe shows the smallest. Early (SSP1-2.6) and no (SSP5-8.5) actions of mitigation would relieve and aggravate the increase rate, respectively. For about 78%-87% of the global land areas, the changes in exposure are mainly caused by climate change (accounting for >69%), followed by the interaction effect (accounting for ~29%) that refers to synergistic changes in climate and population. In parts of mid- to high-latitude regions, the exposure is smaller than expected due to opposite effects of climate change and population change.
归因于全球复合极端高温（将日间-夜间高温与更严重的影响结合在一起）对人口的影响变化，对于气候变化适应至关重要。本研究基于耦合模式比较计划第六阶段（CMIP6）的逐日温度数据和人口数据，在全球和各大洲范围内，在三种排放和社会经济发展情景下，估算了未来两个时期的人口暴露变化，并评估了气候和人口变化的贡献。结果表明，不同时期和情景下，复合极端高温暴露的空间格局相似，高暴露地区主要分布在东亚、南亚、欧洲以及美国东部和非洲部分地区。与基准期（1980-2014 年）相比，在大多数地区，21 世纪中、后期（2021-2055 年和 2056-2090 年）的暴露呈增加趋势。在情景 SSP2-4.5 下，全球暴露在 21 世纪后期增加了约 19 倍，非洲增幅最大，欧洲增幅最小。早缓解（SSP1-2.6）和无缓解（SSP5-8.5）情景分别缓解和加剧了增加速度。对于约 78%-87%的全球陆地面积，暴露变化主要由气候变化引起（占比大于 69%），其次是气候和人口协同变化的交互效应（占比约 29%）。在中高纬度地区的部分地区，由于气候变化和人口变化的相反影响，暴露程度小于预期。
