Climate Change Threatens Irrigation’s Reliance on Snowmelt in Western States

A new study published by The Ohio State University reveals that western U.S. farmers who rely on snowmelt for irrigation will be among the hardest hit in the world by climate change. An interdisciplinary team of researchers analyzed irrigation water demand and snowmelt runoff over a 30-year period and projected how the timing and magnitude of runoff would change under warming of two to four degrees Celsius. They found that areas globally most at risk of not having enough water available at the right times for irrigation because of changes in snowmelt patterns include the San Joaquin and Colorado River basins. The study suggests that under a 4-degree warming scenario, 14% of irrigation water demand in the San Joaquin and 9% in the Colorado river basin would have to be met by new alternative sources to maintain irrigation water supplies.