Yao Yi, Ducharne Agnès, Cook Benjamin I, De Hertog Steven J, Aas Kjetil Schanke, Arboleda-Obando Pedro F, Buzan Jonathan, Colin Jeanne, Costantini Maya, Decharme Bertrand, Lawrence David M, Lawrence Peter, Leung L Ruby, Lo Min-Hui, Devaraju Narayanappa, Wieder William R, Wu Ren-Jie, Zhou Tian, Jägermeyr Jonas, McDermid Sonali, Pokhrel Yadu, Elling Maxwell, Hanasaki Naota, Muñoz Paul, Nazarenko Larissa S, Otta Kedar, Satoh Yusuke, Yokohata Tokuta, Jin Lei, Wang Xuhui, Mishra Vimal, Ghosh Subimal, Thiery Wim
Department of Water and Climate, Vrije Universiteit Brussel, Brussels, Belgium.
Laboratory 7619 METIS, Sorbonne Université, CNRS, EPHE, IPSL, Paris, France.
Nat Commun. 2025 Jan 26;16(1):1045. doi: 10.1038/s41467-025-56356-1.
Irrigation rapidly expanded during the 20 century, affecting climate via water, energy, and biogeochemical changes. Previous assessments of these effects predominantly relied on a single Earth System Model, and therefore suffered from structural model uncertainties. Here we quantify the impacts of historical irrigation expansion on climate by analysing simulation results from six Earth system models participating in the Irrigation Model Intercomparison Project (IRRMIP). Results show that irrigation expansion causes a rapid increase in irrigation water withdrawal, which leads to less frequent 2-meter air temperature heat extremes across heavily irrigated areas (≥4 times less likely). However, due to the irrigation-induced increase in air humidity, the cooling effect of irrigation expansion on moist-heat stress is less pronounced or even reversed, depending on the heat stress metric. In summary, this study indicates that irrigation deployment is not an efficient adaptation measure to escalating human heat stress under climate change, calling for carefully dealing with the increased exposure of local people to moist-heat stress.
灌溉在20世纪迅速扩张，通过水、能源和生物地球化学变化影响气候。先前对这些影响的评估主要依赖于单一的地球系统模型，因此存在结构模型不确定性。在此，我们通过分析参与灌溉模型相互比较项目（IRRMIP）的六个地球系统模型的模拟结果，量化历史灌溉扩张对气候的影响。结果表明，灌溉扩张导致灌溉取水量迅速增加，这使得重度灌溉地区（可能性降低4倍以上）2米气温极端高温事件的发生频率降低。然而，由于灌溉导致空气湿度增加，根据热应激指标，灌溉扩张对湿热应激的降温效果不那么明显，甚至可能相反。总之，本研究表明，在气候变化下，灌溉部署并非应对不断升级的人类热应激的有效适应措施，这就要求谨慎应对当地居民面临的湿热应激增加问题。
