A new global review examined more than 200 studies on how climate change is affecting high-elevation environments. The researchers found that rising temperatures are changing the way winter works in mountain landscapes: more storms are falling as rain instead of snow, and the snow that does accumulate is disappearing earlier in the spring.
Those changes disrupt the natural “water-tower” function that mountains play for much of the West, said John Knowles, a researcher at Montana State University and a co-author of the study.
“They collect precipitation all winter long,” he said. “They store it as snowpack, and then they release it slowly as nature's drip irrigation system all summer long, when we need it the most.”
But with warming trends accelerating at high elevations, that steady supply is becoming less reliable. Instead of slowly melting snow feeding rivers into late summer, more water is now running off earlier in the year — leaving streams and reservoirs lower during the hottest months.
Scientists warn that could strain ecosystems, increase wildfire risk, and intensify competition for water among farms, cities and tribes across the region.
Researchers say understanding these elevation-driven changes will be critical as Mountain West communities plan for a hotter, drier and less predictable future.
This story was produced by the Mountain West News Bureau, a collaboration between KUNR, Wyoming Public Media, Nevada Public Radio, Boise State Public Radio in Idaho, KUNC in Northern Colorado, KANW in New Mexico, Colorado Public Radio, KJZZ in Arizona and NPR, with additional support from affiliate newsrooms across the region. Funding for the Mountain West News Bureau is provided in part by the Corporation for Public Broadcasting and Eric and Wendy Schmidt.
