A changing climate caused the rapid build-up of greenhouse gases in the Earth’s atmosphere will likely have profound impacts on the Colorado River basin. Warmer weather, less snow, a reduction in stream runoff, and changed timing of spring runoff are all likely impacts. Recent modeling suggests that a 10% reduction in stream runoff may cause delivery shortages in Las Vegas 58% of the time by the year 2050. A more recent study by the Bureau of Reclamation suggests that in as little as 2 years, there is a 20% chance that Lake Mead’s water level could drop too low to produce electricity or supply enough water to Las Vegas.

Water supplies to the entire basin may be impacted by climate change. Recent studies by the State of Colorado suggest that if climate change forecasts come true, water providers in Colorado may use all of water available to them through their legal allocation, thus reducing the amount of water that flows downstream for other cities as well as for the environment. Cities and water districts up and down the basin – as well as the U.S. Department of Interior – are spending vast amounts of money trying to understand and predict the extent and impacts of climate change on the Colorado River.