Featured Research

from universities, journals, and other organizations

Human-caused Climate Change At Root Of Diminishing Water Flow In Western US, Scientists Find

Date:
February 1, 2008
Source:
DOE/Lawrence Livermore National Laboratory
Summary:
The Rocky Mountains have warmed by 2 degrees Fahrenheit. The snowpack in the Sierras has dwindled by 20 percent and the temperatures there have heated up by 1.7 degrees Fahrenheit. All could lead to dire consequences for the water supply in the Western United States, including California. Scientists have noted that water flow in the West has decreased for the last 20 to 30 years, but had never explained why it was happening.

Mid-latitude glaciers respond quickly and dramatically to fluctuations in climate. Aerial views of South Cascade Glacier, Washington, in 1928 and 2000, illustrate the magnitude of glacier wastage (negative mass balance) and the terminus retreat that has been characteristic of glaciers in the region. Over this time span, the glacier has lost half its volume and retreated 1.5 km.
Credit: USGS

The Rocky Mountains have warmed by 2 degrees Fahrenheit. The snowpack in the Sierras has dwindled by 20 percent and the temperatures there have heated up by 1.7 degrees Fahrenheit.

All could lead to dire consequences for the water supply in the Western United States, including California. Scientists have noted that water flow in the West has decreased for the last 20 to 30 years, but had never explained why it was happening.

Until now. Scientists from Lawrence Livermore National Laboratory’s Program for Climate Model Diagnosis and Intercomparison in collaboration with Scripps Institution of Oceanography, have pinpointed the cause of that diminishing water flow on a regional scale: humans.

“We looked at whether there is a human-caused climate change where we live, and in aspects of our climate that we really care about,” said Benjamin Santer of LLNL and co-author of the paper. “No matter what we did, we couldn’t shake this robust conclusion that human-caused warming is affecting water resources here in the Western United States.”

By looking at air temperatures, river flow and snowpack over the last 50 years, the team determined that the human-induced increase in greenhouse gases has seriously affected the water supply in the West. And the future brings more of the same.

“It’s pretty much the same throughout all of the Western United States,” said Tim Barnett of Scripps and a co-author of the paper.* “The results are being driven by temperature change. And that temperature change is caused by us.”

The team scaled down global climate models to the regional scale and compared the results to observations over the last 50 years. The results were solid, giving the team confidence that they could use the same models to predict the effects of the global scale increase in greenhouse gases on the Western United States in the future.

The projected consequences are bleak.

By 2040, most of the snowpack in the Sierras and Colorado Rockies would melt by April 1 of each year because of rising air temperatures. The earlier snow melt would lead to a shift in river flows.

The shift could lead to flooding in California’s Central Valley. Currently, state reservoirs are filled during the rainy season. As the water is drawn down, the reservoirs are replenished with snow melt from the Sierras.

If that snow melts earlier, as predicted in the climate models, the reservoirs could overflow.

“We are headed for a water crisis in the Western United States that has already started,” Barnett said. “A couple of decades ahead, we might not have that snowpack, making us more susceptible to flooding.”

Santer said the increase in predicted river flow should be a wake- up call to officials that the water supply infrastructure needs to be updated now, as opposed to waiting until the situation is urgent.

As for the warming, with the existing greenhouse gas in the atmosphere, the Earth will continue to warm for the next 80-100 years.

“For someone who has seven grandchildren, that scares the hell out of me,” Barnett said. “I’ve seen the future and I don’t like it.”

*The research appears in the Jan. 31 online edition of Science Express. The findings also were presented at last year’s annual fall meeting of the American Geophysical Union.


Story Source:

The above story is based on materials provided by DOE/Lawrence Livermore National Laboratory. Note: Materials may be edited for content and length.


Cite This Page:

DOE/Lawrence Livermore National Laboratory. "Human-caused Climate Change At Root Of Diminishing Water Flow In Western US, Scientists Find." ScienceDaily. ScienceDaily, 1 February 2008. <www.sciencedaily.com/releases/2008/01/080131161810.htm>.
DOE/Lawrence Livermore National Laboratory. (2008, February 1). Human-caused Climate Change At Root Of Diminishing Water Flow In Western US, Scientists Find. ScienceDaily. Retrieved August 23, 2014 from www.sciencedaily.com/releases/2008/01/080131161810.htm
DOE/Lawrence Livermore National Laboratory. "Human-caused Climate Change At Root Of Diminishing Water Flow In Western US, Scientists Find." ScienceDaily. www.sciencedaily.com/releases/2008/01/080131161810.htm (accessed August 23, 2014).

Share This




More Earth & Climate News

Saturday, August 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Airlines on Iceland Volcano Alert

Airlines on Iceland Volcano Alert

Reuters - Business Video Online (Aug. 22, 2014) Iceland evacuates an area north of the country's Bardarbunga volcano, as the country's civil protection agency says it cannot rule out an eruption. Authorities have already warned airlines. As Joel Flynn reports, ash from the eruption of the Eyjafjallajokull volcano in 2010 shut down much of Europe's airspace for six days. Video provided by Reuters
Powered by NewsLook.com
Endangered Red Wolves Face Uncertain Future

Endangered Red Wolves Face Uncertain Future

AP (Aug. 22, 2014) A federal judge temporarily banned coyote hunting to save endangered red wolves, but local hunters say that the wolf preservation program does more harm than good. Meanwhile federal officials are reviewing its wolf program in North Carolina. (Aug. 22) Video provided by AP
Powered by NewsLook.com
Coal Gas Boom in China Holds Climate Risks

Coal Gas Boom in China Holds Climate Risks

AP (Aug. 22, 2014) China's energy revolution could do more harm than good for the environment, despite the country's commitment to reducing pollution and curbing its carbon emissions. (Aug. 22) Video provided by AP
Powered by NewsLook.com
Microbrewery Chooses Special Can for Its Beer

Microbrewery Chooses Special Can for Its Beer

AP (Aug. 22, 2014) Aluminum giant, Novelis, has partnered with Red Hare Brewing Company to introduce the first certified high-content recycled beverage can. (Aug. 22) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins