Summer forecast calls for intensifying drought across American West

Greenhouse gases, aerosols emitted by human activity are make droughts worse.

The western United States is in the midst of an intensifying drought. In the latest U.S. Drought Monitor released Thursday, nearly 52% of the western U.S. is in "extreme" or "exceptional drought." In parts of California and Nevada, two dry winters in a row, and a very weak monsoon in 2020 have combined to create massive precipitation deficits. Parts of this region are likely seeing the worst second sequential year of drought in over 30 years. Since the start of the water year, which began Oct. 1, 2020, major American cities in the West have seen well below average precipitation. Downtown San Francisco is over a foot below their water year average. Redding, California, is over 17 inches below their water year average. Phoenix, Las Vegas and Salt Lake City all are few inches below their water year average. "California's drought has recently gone from bad to worse," UCLA climate scientist Daniel Swain told ABC News. "This striking increase in drought severity has been driven by several factors, including extremely low rainfall, warmer than typical historical temperatures and unusually rapid snowmelt in mountain areas. Warming temperatures, a declining snowpack and a narrowing rainy season are all hallmarks of climate change in the region."