The dependence of lowland populations on mountain water resources will grow by mid-century across several climate and socioeconomic scenarios, and several seasonally dry or semiarid mountain regions  are projected to be highly dependent on such resources   . Changing sediment, nutrient and pollutant flows due to climatic and non-climatic drivers will impact populations and economic sectors . Hydropower in all mountain regions will experience higher fluxes of water and sediment in some seasons but lower water flow with demand from other water uses   in other seasons . Recharge from groundwater and its buffer function is expected to decrease in the longer term . Glacier and snow depth or mass decline will impact current hydropower facilities and production in various complex ways, requiring changes in hydropower management, with further potential for evidence-informed solutions . On the other hand, deglaciation in mountain regions opens topographic space and, thus, potential for additional long-term hydropower development and production , with an estimated additional production of up to several hundred terawatt-hours per year, a potentially important contribution
IPCC
Climate Change 2022: Impacts, Adaptation and Vulnerability
IPCC Report