Terrestrial water storage (TWS) over the Tibetan Plateau, a major global water tower, is crucial in determining water transport and availability to a large downstream Asian population. Climate change impacts on historical and future TWS changes, however, are not well quantified. Here we used bottom-up and top-down approaches to quantify a significant TWS decrease (10.2 Gt yr^–1) over the Tibetan Plateau in recent decades (2002–2017), reflecting competing effects of glacier retreat, lake expansion and subsurface water loss. Despite the weakened trends in projected TWS, it shows large declines under a mid-range carbon emissions scenario by the mid-twenty-first century. Excess water-loss projections for the Amu Darya and Indus basins present a critical water resource threat, indicating declines of 119% and 79% in water-supply capacity, respectively. Our study highlights these two hotspots as being at risk from climate change, informing adaptation strategies for these highly vulnerable regions.

青藏高原上的陆地蓄水（TWS）是全球主要的水塔，对于确定大量下游亚洲人口的水运输和可用性至关重要。然而，气候变化对历史和未来 TWS 变化的影响并没有得到很好的量化。在这里，我们使用自下而上和自上而下的方法来量化 TWS 的显着下降（10.2 Gt yr ^–1) 近几十年（2002-2017 年）在青藏高原上空，反映了冰川退缩、湖泊扩张和地下水流失的竞争效应。尽管预计的 TWS 趋势减弱，但到 21 世纪中叶，在中等碳排放情景下，它显示出大幅下降。阿姆河和印度河流域的过度水损失预测对水资源构成严重威胁，供水能力分别下降 119% 和 79%。我们的研究强调这两个热点正面临气候变化的风险，为这些高度脆弱地区的适应战略提供信息。