Evolving resource potential of glacial lakes with ongoing deglaciation

Abstract Melting and retreating glaciers are generating meltwater and creating space for new glacial lakes in Earth’s high mountains. These glacial lakes become increasingly important freshwater reservoirs, but their value for hydropower, drinking water supply, tourism and ecosystem services over decades depends on their storage capacity and sedimentation-dependent lifespan. Here we estimate the volumes and sediment storage capacities for ~71,000 glacial lakes globally as of 2020. Combined, these lakes impound a water volume of $${\mathrm{2,048}}_{{-}296}^{+218}$$ 2,048 − 296 + 218 km³ (median and 68% highest density interval), representing a $${+12.7}_{{-}13.2}^{+9.1} \%$$ + 12.7 − 13.2 + 9.1 % change compared with 1990. Half of the 2020 glacial lake water volume is located within 63 km of a coastline and below 200 m above sea level, mostly in sparsely populated, high-latitude regions such as Greenland, Arctic Canada, Patagonia and Alaska, where use of, and demand for, freshwater remains limited. The smallest lakes (