Human emissions drove the megadrought in the western U.S.

[OKIsItJustMe]

https://www.colorado.edu/today/2025/08/14/human-emissions-drove-megadrought-western-us

Human emissions drove the megadrought in the western U.S.
8/14/2025 • By Yvaine Ye

Greenhouse gas and aerosol emissions from human activity have been driving the prolonged drought in the western United States through a complicated connection with the Pacific Ocean, according to a new CU Boulder-led study.

For more than two decades, an extreme dry spell has drained the Colorado River, devastated local farms, and intensified wildfires across the American Southwest. The new prediction, published August 13 in Nature, could help water managers region develop better water use plans or invest in infrastructure accordingly, with relief potentially still decades away.

“Our results show that the drought and ocean patterns we’re seeing today are not just natural fluctuations—they’re largely driven by human activity,” said Jeremy Klavans, postdoctoral researcher in CU Boulder’s Department of Atmospheric and Oceanic Sciences and lead author of the study.

…

As a result, scientists estimated that about 93% of the western United States is experiencing drought, with 70% facing severe dry conditions. Prior studies have shown that the past two decades have been the driest in the American Southwest in at least 1,200 years.

…

Klavans, J.M., DiNezio, P.N., Clement, A.C. et al. Human emissions drive recent trends in North Pacific climate variations. Nature (2025). https://doi.org/10.1038/s41586-025-09368-2


(See related research: Relief From Drought in Southwest U.S. Likely Isn't Coming, According to New Research)

[CrispyQ]

1. "The new prediction...could help water managers region develop better water use plans..."

I'd add an LOL emoji but this is a serious issue & the states involved have done basically nothing to address it. This is not just a regular earthly cycle that we have to wait out.

[OKIsItJustMe]

2. I hear you

I usually try to avoid editorializing on the science, however, it’s hard for me to imagine them successfully overcoming this.

https://www.8newsnow.com/news/local-news/las-vegas-valleys-water-use-more-efficient-snwas-goal-is-a-10-improvement/

Las Vegas valley’s water use more efficient; SNWA’s goal is a 10% improvement
by: Greg Haas
Posted: Aug 14, 2025 / 01:06 PM PDT
Updated: Aug 14, 2025 / 01:06 PM PDT

LAS VEGAS (KLAS) — So far this year, 88.3 billion gallons has been pumped from Lake Mead to the Las Vegas valley. And 47.6 billion gallons have gone back to the lake.

…

“In 2002, Southern Nevada consumed 325,000 acre-feet of water (105.9 billion gallons) – that was our highest water-use year, and it was also the year the drought was declared on the Colorado River,” Mack said.

“In response, Southern Nevada started implementing the progressive and comprehensive water conservation programs and policies in 2003. To take that a bit further, consumptive water use in our community declined by approximately 38 billion gallons between 2002 and 2024, despite the influx of approximately 829,000 new residents and nearly 42 million annual visitors during that span. The reason for that decline in water use is the community’s amazing response to conserve water,” he said.

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The Southern Nevada Water Authority (SNWA) has identified a goal: Cut water use by another 10% over the next 10 years.

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Their accomplishment really is impressive, but, I believe, insufficient.