Nature Climate Change, Published online: 14 July 2026; doi:10.1038/s41558-026-02699-6The timescale on which river runoff reacts to glacier melt changes differs strongly between individual basins. Here we discuss how an article published in 2018 linked the buffering role of glaciers to future seasonal runoff losses, and how later work has extended this insight towards drought, water resources and the consequences for downstream societies.