Volume of water lost equal to Lake Mead, US’s largest reservoir, or enough water to fill around 15bn Olympic-sized pools, study finds
Oliver Milman
The Guardian
The climate crisis has caused the ailing Colorado River basin, a system relied upon by 40 million people in the US west, to lose more than 10tn gallons of water in the last two decades, new research has found.
The volume of water lost due to rising global temperatures has been so enormous that it is equal to the entire storage capacity of Lake Mead, the US’s largest reservoir that was formed by the Hoover Dam, or enough water to fill about 15m Olympic-sized swimming pools.
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The Colorado River provides vital water supplies to people across the US west, as well as nourishes ecosystems and millions of acres of farmland, but has dwindled since 2000 due to a “megadrought” that has been significantly worsened by climate change.
Without the influence of human-caused global heating, researchers for the new study found, reservoir levels wouldn’t have slumped to such low levels that the first ever federally declared water shortage was declared, requiring a desperate, temporary deal to be struck between states in May to cut water use.
Benjamin Bass, a hydrological modeler at the University of California-Los Angeles and lead author of the study, said the researchers were “surprised” at how sensitive the Colorado River basin is to warming temperatures.
“The fact that warming removed as much water from the basin as the size of Lake Mead itself during the recent megadrought is a wakeup call to the climate change impacts we are living today,” Bass said.
