Climate Change Is Shrinking the Colorado River

[petronius]

The nation’s two largest reservoirs, Lake Mead on the Arizona/Nevada border and Lake Powell on the Arizona/Utah border, were brim full in the year 2000. Four short years later, they had lost enough water to supply California its legally apportioned share of Colorado River water for more than five years. Now, 17 years later, they still have not recovered.

This ongoing, unprecedented event threatens water supplies to Los Angeles, San Diego, Phoenix, Tucson, Denver, Salt Lake City, Albuquerque and some of the most productive agricultural lands anywhere in the world. It is critical to understand what is causing it so water managers can make realistic water use and conservation plans.

While overuse has played a part, a significant portion of the reservoir decline is due to an ongoing drought, which started in 2000 and has led to substantial reductions in river flows. Most droughts are caused by a lack of precipitation. However, our published research shows that about one-third of the flow decline was likely due to higher temperatures in the Colorado River’s Upper Basin, which result from climate change.

This distinction matters because climate change is causing long-term warming that will continue for centuries. As the current “hot drought” shows, climate change-induced warming has the potential to make all droughts more serious, turning what would have been modest droughts into severe ones, and severe ones into unprecedented ones.

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https://indiancountrymedianetwork.com/news/environment/climate-change-shrinking-colorado-river/


Caption: The combined contents of the nation’s two largest reservoirs, Lake Mead and Lake Powell, since their initial fillings. The large decline since 2000 is shaded brown for 2000-2014, our 15-year study period, and pink for the continuing drought in 2015-2016. The loss was significantly influenced by record-setting temperatures, unlike a similar 15-year drought in the 1950s which was driven by a lack of precipitation. (Bradley Udall, Author provided)




Lots of excellent links and graphics at the article source, and a much longer discussion...

[murielm99]

1. Thanks for posting. n/t