Sino-French Institute for Earth System Science, College of Urban and Environmental Sciences, Peking University, 100871, Beijing, China.
Key Laboratory of Alpine Ecology and Biodiversity, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, 100101, Beijing, China.
Nat Commun. 2020 Oct 14;11(1):5184. doi: 10.1038/s41467-020-18992-7.
The global monsoon is characterised by transitions between pronounced dry and wet seasons, affecting food security for two-thirds of the world's population. Rising atmospheric CO influences the terrestrial hydrological cycle through climate-radiative and vegetation-physiological forcings. How these two forcings affect the seasonal intensity and characteristics of monsoonal precipitation and runoff is poorly understood. Here we use four Earth System Models to show that in a CO-enriched climate, radiative forcing changes drive annual precipitation increases for most monsoon regions. Further, vegetation feedbacks substantially affect annual precipitation in North and South America and Australia monsoon regions. In the dry season, runoff increases over most monsoon regions, due to stomatal closure-driven evapotranspiration reductions and associated atmospheric circulation change. Our results imply that flood risks may amplify in the wet season. However, the lengthening of the monsoon rainfall season and reduced evapotranspiration will shorten the water resources scarcity period for most monsoon regions.
全球季风的特点是明显的干湿季节交替，影响了世界上三分之二人口的粮食安全。大气 CO 的增加通过气候辐射和植被生理强迫来影响陆地水文循环。这两种强迫如何影响季风降水和径流水文季节性强度和特征，目前还知之甚少。在这里，我们使用四个地球系统模型表明，在 CO 富集气候下，辐射强迫变化导致大多数季风区的年降水量增加。此外，植被反馈对北美、南美和澳大利亚季风区的年降水量有很大影响。在旱季，由于气孔关闭导致的蒸散减少和相关大气环流变化，大多数季风区的径流量增加。我们的研究结果表明，洪水风险可能会在雨季加剧。然而，季风降雨季节的延长和蒸散的减少将缩短大多数季风区水资源短缺的时期。
