 Mountains provide essential sources of fresh water to the world, but their role in global water resources could be significantly altered by climate change. Despite some progress, there is still much to learn about the potential impacts of climate change on mountain water resources. Research needs to focus on understanding the effects of climate change on precipitation, snow water equivalent, soil parameters, evaporation and transpiration, groundwater, and enhanced warming and feedback mechanisms. Additionally, environmental monitoring at high altitudes should be emphasized. Finally, research, water resource management, and policy need to work together to ensure effective management of mountain water resources. This article was authored by D. Viveroli, D. R. Archer, W. Bytard, and others.