Observed changes in dry-season water availability attributed to human-induced climate change
Observed changes in dry-season water availability attributed to human-induced climate change
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DOI：
10.1038/s41561-020-0594-1
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发表时间：
2020-06
影响因子：
18.3
通讯作者：
Ryan S. Padrón;L. Gudmundsson;B. Decharme;A. Ducharne;D. Lawrence;J. Mao;D. Peano;G. Krinner
中科院分区：
文献类型：
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作者：
Ryan S. Padrón;L. Gudmundsson;B. Decharme;A. Ducharne;D. Lawrence;J. Mao;D. Peano;G. Krinner
人为引起的气候变化影响水文循环，从而影响水资源的可用性。然而，之前对观测到的变暖引起的干燥变化的评估并未排除自然气候变化，并且由于我们对蒸散量响应的理解存在不确定性，因此显示出相互矛盾的结果。在这里，我们采用数据驱动和陆地表面模型，对 1902 年至 2014 年期间的全球可用水资源进行基于观测的重建，在此期间，我们的星球经历了约 1°C 的全球变暖。我们的分析揭示了与二十世纪上半叶相比，过去三十年中一年中最干旱的月份平均可用水量变化的空间模式，一些地区的可用水量增加，一些地区的可用水量减少。全球模式与考虑了人为影响的气候模型估计是一致的，并且不是自然气候变化的预期结果，支持人类引起的气候变化是原因。有区域证据表明，干燥的旱季主要出现在温带纬度地区，包括欧洲、北美西部、亚洲北部、南美洲南部、澳大利亚和非洲东部。我们还发现，旱季的加剧通常是蒸散量增加而不是降水量减少的结果。
Human-induced climate change impacts the hydrological cycle and thus the availability of water resources. However, previous assessments of observed warming-induced changes in dryness have not excluded natural climate variability and show conflicting results due to uncertainties in our understanding of the response of evapotranspiration. Here we employ data-driven and land-surface models to produce observation-based global reconstructions of water availability from 1902 to 2014, a period during which our planet experienced a global warming of approximately 1 °C. Our analysis reveals a spatial pattern of changes in average water availability during the driest month of the year over the past three decades compared with the first half of the twentieth century, with some regions experiencing increased and some decreased water availability. The global pattern is consistent with climate model estimates that account for anthropogenic effects, and it is not expected from natural climate variability, supporting human-induced climate change as the cause. There is regional evidence of drier dry seasons predominantly in extratropical latitudes and including Europe, western North America, northern Asia, southern South America, Australia and eastern Africa. We also find that the intensification of the dry season is generally a consequence of increasing evapotranspiration rather than decreasing precipitation.