The Colorado River Basin in the US has witnessed a huge loss of over 10 trillion gallons of water between 2000 and 2021, primarily due to increasing temperatures caused by climate change. The harmful effects of global warming are being acutely felt across the United States, with extreme heatwaves in the southern region, leaving Americans struggling with unprecedented climate shifts.
The impact of this water loss is particularly alarming as the Colorado River flows through seven Western states and serves as a vital source of water for approximately 40 million people in the country. Researchers have underscored the role of human-induced climate change in the substantial decline of this lifeline river.
According to a study published in the American Geophysical Union’s Water Resources Research, the Western region’s extreme temperatures have led to an alarming 10% reduction in the river’s flow over the last two decades.
The consequences of this significant water loss have already started to materialize. In January 2022, the basin experienced its first-ever water shortage, known as the Tier 1 shortage. This was followed by a Tier 2 shortage declared in January 2023, as water levels in Lake Mead, the largest reservoir in the USA, continued to drop.
Lead author of the study, Benjamin Bass, a water resources engineer, emphasized the study’s objective was to comprehensively examine the impacts of the long-term mega-drought and the role of climate change on Lake Mead’s water levels.
The reservoir’s water level witnessed an alarming drop of 20 feet in just four months during the previous summer. By July 2022, Lake Mead hit its lowest recorded level, with a lake elevation of 1040 feet, narrowly avoiding a “dead pool,” the critical point at which it would be unable to provide water and hydroelectric power to millions of Americans.
A significant factor contributing to the crisis is the escalating evaporation in snowier states like Colorado, where the Colorado River’s headwaters originate. Benjamin highlighted that water reduction is occurring “twice as fast” in these snowy regions due to the positive albedo effect. This phenomenon arises when higher temperatures cause more snow to melt, exposing darker ground that absorbs additional heat, further exacerbating the problem.
As the US grapples with the consequences of climate change, the Colorado River Basin’s plight serves as a stark reminder of the urgent need to address global warming.