Terrestrial water storage (TWS) modulates the hydrological cycle and is a key determinant of water availability and an indicator of drought. While historical TWS variations have been increasingly studied, future changes in TWS and the linkages to droughts remain unexamined. Here, using ensemble hydrological simulations, we show that climate change could reduce TWS in many regions, especially those in the Southern Hemisphere. Strong inter-ensemble agreement indicates high confidence in the projected changes that are driven primarily by climate forcing rather than land and water management activities. Declines in TWS translate to increases in future droughts. By the late twenty-first century, the global land area and population in extreme-to-exceptional TWS drought could more than double, each increasing from 3% during 1976–2005 to 7% and 8%, respectively. Our findings highlight the importance of climate change mitigation to avoid adverse TWS impacts and increased droughts, and the need for improved water resource management and adaptation.

陆地蓄水 (TWS) 调节水文循环，是水资源可用性的关键决定因素和干旱指标。尽管对历史 TWS 变化的研究越来越多，但 TWS 的未来变化以及与干旱的联系仍未得到检验。在这里，使用集合水文模拟，我们表明气候变化可能会降低许多地区的 TWS，尤其是南半球的地区。强烈的集合间协议表明对主要由气候强迫而非土地和水管理活动驱动的预计变化具有高度信心。TWS 的下降转化为未来干旱的增加。到 21 世纪后期，全球发生极端到异常干旱的土地面积和人口可能会增加一倍以上，从 1976 年至 2005 年期间的 3% 分别增长到 7% 和 8%，分别。我们的研究结果强调了减缓气候变化对避免不利的 TWS 影响和干旱增加的重要性，以及改进水资源管理和适应的必要性。