The accelerated glacier melt threatens water, food, and energy security for nearly two billion people dependent on the HKH river systems. Increased GLOF risks endanger downstream communities and infrastructure, as seen in the recent Nepal flash flood disaster. The retreat of smaller glaciers is expected to exacerbate water stress in the Ganga and Brahmaputra basins, with some rivers at risk of becoming seasonal. Biodiversity and ecosystems in the region are also under threat, even under moderate warming scenarios.