Here’s part one of the series from Climate Central (Tom Yulsman/Brendon Bosworth)
Plot spoiler: They maintain that westerners are obsessive about winter snowpack. I’ll agree that some of us are. From the article:
In recent weeks, water managers, skiers and farmers, if not city folk, from California all the way to Colorado were breathing a little easier with the news that storms have significantly boosted both mountain snowpack and the water supply outlook in the Colorado River Basin.
As of January 6, the average snow water equivalent for most of the basin was at 141 percent of the long-term average. (Snow water equivalent is the depth of the water you’d collect if you melted a given amount of snow instantaneously). This is the very best start to the year since 1997, according to the Colorado Basin River Forecast Center.
Here’s part two of the series from Climate Central (Brendon Bosworth/Tom Yulsman). They look at the future of the basin. From the article:
During the past few decades of rapid growth in water use, “the hydrological cycle in the region began to change,” write Tim Barnett and David Pierce of the Scripps Institution of Oceanography, in a 2009 study published in the Proceedings of the National Academy of Sciences.
“Snowpack declined in the western mountains, temperatures increased, and many streams gradually shifted their peak flow to earlier in the year,” they continued. “It has been shown, with very high statistical confidence, that a substantial portion of these changes are attributable to human-induced effects on the climate.”
But Brad Udall, director of the Western Water Assessment of the University of Colorado, is a bit more cautious: “The way science and statistics work is that there’s a really high bar set to say, ‘Okay, this particular event is actually climate change and not just natural variability.’ In fact that bar is so high, frequently all you can say is, ‘hey, this is consistent with what we think climate change will bring.’ I think this is in many ways is where we are in the Colorado River.”
Regardless of whether the recent drought has a man-made component or not, computer modeling of the climate system is not reassuring about the future. It indicates that the Colorado River basin will become warmer and more arid in coming decades. In fact, this is one of the more robust findings shared among most of the climate models.
Rust colored desert dust on the snowpack has been causing snow to melt on average three weeks earlier than it did before human activities in the West disturbed its pristine ecosystem, around the middle of the 19th century, according to a study by researchers from NASA’s Jet Propulsion Laboratory and the University of Colorado’s Cooperative Institute for Research in Environmental Sciences (CIRES). (For a CIRES press release on the research, go here.)
This has been robbing the river of some 750,000 acre-feet of water each year, on average, compared to the undisturbed conditions that preceded human settlement. Astonishingly, that’s enough to supply the entire city of Los Angeles for 18 months.
These findings come at a time when the Southwest is in its 11th year of the most severe drought since 1900, and increasing water demands from expanding cities are placing added strain on the Colorado River.
To learn more about what’s going on, I visited study co-author Jeffrey Deems in his office at the National Snow and Ice Data Center in Boulder, Colorado. As part of his research, he digs pits in the snowpack to examine layers of compressed dust buried by fresh snowfall.
More Colorado River basin coverage here.