The problem of evaluating the hydrological effects of climate change has opened a new field of applications for snowmelt runoff models. The Snowmelt Runoff Model (SRM) has been used to evaluate climate change effects on basins in North America, the Swiss Alps, and the Himalayas. Snow covered area depletes about one month earlier in response to warmer temperatures (+40C) with runoff peaks shifted accordingly. Runoff will be higher in winter at the expense of summer runoff. In glacerized basins, runoff is not only redistributed, but increased due to glacier melting. This improved knowledge facilitates long-term decisions concerning hydropower, flooding, water allocations, and water management in general.