News / Science & Technology

Global Warming Might Threaten Water Supply

Frank Gehrke, right, Chief of California Cooperative Snow Surveys Program measures the snowpack in California’s Sierra Nevada Mountains. (California Dept. of Water Resources)
Frank Gehrke, right, Chief of California Cooperative Snow Surveys Program measures the snowpack in California’s Sierra Nevada Mountains. (California Dept. of Water Resources)
Rosanne Skirble
Global warming over the next century could significantly reduce the amount of winter snowpack in mountainous areas in the northern hemisphere, according to a new study published in Nature Climate Change.

Seasonal snowpack melt is an essential source of fresh water, and its loss could threaten drinking water supplies, agricultural irrigation and wildlife ecosystems.

Stanford University climate expert Noah Diffenbaugh led the study, which compares snowpack conditions across the northern hemisphere in the late 20th century with climate model projections for the next one hundred years.

Deceasing snowpack

Those projections are based on a range of scenarios which foresee a rise in average global temperatures of between two and four degrees Celsius.

Snowpack Climate Change
Snowpack Climate Changei
|| 0:00:00
...
 
🔇
X

The study concludes that average snow accumulation will decrease in most regions of the Western United States, Europe, Central Asia and the Himalayas, compared to historical patterns.  

It projects that low and extremely low snow falls would exceed the lows of the later 20th century between 10 and 30 percent of the time with two degrees of warming.
California is the world’s sixth largest agricultural exporter and is dependent on snowpack for those crops. (California Dept. of Water Resources)California is the world’s sixth largest agricultural exporter and is dependent on snowpack for those crops. (California Dept. of Water Resources)
x
California is the world’s sixth largest agricultural exporter and is dependent on snowpack for those crops. (California Dept. of Water Resources)
California is the world’s sixth largest agricultural exporter and is dependent on snowpack for those crops. (California Dept. of Water Resources)

And, Diffenbaugh says, "If the planet warms by 4 degrees Celsius, the United could experience snowpack accumulations below the levels of the late 20th century up to 80 percent of the years.”

The story is the same in other parts of the northern hemisphere, where snowpack is a natural, and critical, water reservoir.  

Water worries

The study finds that an early spring melt would bring more water into the watershed sooner than usual, potentially flooding rivers, lakes and artificially dammed-river reservoirs.

And with less water available later in the season, chances for more wildfires, pests, and species extinctions increase.  

Diffenbaugh says this timing would also exacerbate drought conditions when the demand for water is greatest.

“We can infer that should these physical climate changes occur in the future, that there would be impacts on water supply for agriculture and for human consumption and for natural ecosystems if the water storage and management systems are not adapted to those changes.”

According to climate models, extreme rain events are expected to increase as the planet warms.  

However, Diffenbaugh says, that won’t change how the snowpack responds to climate change. 

“Even where there are increases in extreme precipitation in the models, there are still robust decreases in the amount of snowpack on the ground at the end of the winter and in robust changes in the timing of runoff.”

California experiencing climate extremes

Frank Gehrke takes these findings very seriously. He heads the California Cooperative Snow Surveys program, which forecasts water flow from the mountains into man-made reservoirs that provide water for crops and people.

California is just one part of a broader picture discussed in the report. Since the state gets little rain in the spring and summer, Gehrke says timing of snow pack melt is critical.  

He says he is seeing greater climate variation than ever before. “We’re having more extremes in terms of dry and wet years. We see that not only in our record, but also in discussions with a lot of other people who are studying climate.”  
California will fine tune its snowpack measurements using new instruments on aircraft that can give water managers accurate data on snow accumulation and rate of melt. (NASA)California will fine tune its snowpack measurements using new instruments on aircraft that can give water managers accurate data on snow accumulation and rate of melt. (NASA)
x
California will fine tune its snowpack measurements using new instruments on aircraft that can give water managers accurate data on snow accumulation and rate of melt. (NASA)
California will fine tune its snowpack measurements using new instruments on aircraft that can give water managers accurate data on snow accumulation and rate of melt. (NASA)

Gehrke says California water managers need better measurement tools and higher resolution aerial images of the state’s snowpack than were available in the Stanford study. For that, the state has turned to the U.S. space agency’s Airborne Snow Observatory.  

Flying at altitudes of about 7,000 meters, the photo-reconnaissance aircraft capture detailed images of mountain snowpack over a wide area, allowing scientists to more accurately compute the entire volume of water in a given watershed.   

The NASA flights will also measure how much sun is reflected from the snowpack, which can indicate how fast it is likely to melt.

You May Like

Pundits Split Over Long-Term US Role in Afghanistan

Security pact remains condition for American presence beyond 2014; deadline criticized More

US Eyes Islamic State Threat

Officials warn that IS could pose a threat to US homeland More

Video Ukraine: Captured Troops Proof of Russian Role in Separatist Fight

Moscow says Russian troops crossed into Ukrainian territory by mistake More

This forum has been closed.
Comment Sorting
Comments
     
by: riano baggy from: ina
November 12, 2012 12:04 AM
next decade we didn't see snow in high mountains,melting ice can high sea level,very ports must redesign again to more budget,ecosystem disturbed. and many side effect can appears..

Featured Videos

Your JavaScript is turned off or you have an old version of Adobe's Flash Player. Get the latest Flash player.
Scientists Unlock Mystery of Bird Flocksi
X
George Putic
August 25, 2014 4:00 PM
How can flocks of birds, schools of fish or herds of antelope suddenly change direction -- all the individuals adjusting their movement in concert, at seemingly the same time? British researchers now have some insights into this behavior, which has puzzled scientists for a long time. VOA's George Putic has more.
Video

Video Scientists Unlock Mystery of Bird Flocks

How can flocks of birds, schools of fish or herds of antelope suddenly change direction -- all the individuals adjusting their movement in concert, at seemingly the same time? British researchers now have some insights into this behavior, which has puzzled scientists for a long time. VOA's George Putic has more.
Video

Video Ukraine: Captured Troops Proof of Russian Role in Separatist Fight

Ukrainian officials say they have captured Russian soldiers on Ukrainian territory -- the latest accusation of Moscow's involvement in the conflict in eastern Ukraine. VOA's Gabe Joselow reports from the Ukrainian side of the battle, where soldiers are convinced of Russia's role.
Video

Video Rubber May Soon Come From Dandelions

Synthetic rubber has been around for more than a century, but quality tires for cars, trucks and aircraft still need up to 40 percent or more natural rubber content. As the source of natural rubber, the rubber tree, is prone to disease and can be affected by bad weather. So scientists are looking for replacements. And as VOA’s George Putic reports, they may have found one in a ubiquitous weed.
Video

Video Jewish Life in Argentina Reflected in Yiddish Tango

Jewish people from across Europe and Russia have been immigrating to Argentina for hundreds of years. They brought with them dance music that were eventually mixed with Argentine tango. The result is Yiddish tango -- a fusion of melodies and cultural experiences that is still evolving today. Elizabeth Lee reports from the Skirball Cultural Center in Los Angeles, where one band is bringing Yiddish tango to an American audience.
Video

Video Peace Returns to Ferguson as Community Tries to Heal

Thousands of people nationwide are expected to attend funeral services Monday in the U.S. Midwestern city of St. Louis, Missouri, for Michael Brown, the unarmed African-American teenager who was fatally shot by a white police officer August 9 in the St. Louis suburb of Ferguson. The shooting touched off days of violent demonstrations there, resulting in more than 100 arrests. VOA's Chris Simkins reports from Ferguson where the community is trying to move on after weeks of racial tension.
Video

Video Meeting in Minsk May Hinge on Putin Story

The presidents of Russia and Ukraine are expected to meet face-to-face Tuesday in Minsk, along with European leaders, for talks on the situation in Ukraine. Political analysts say the much welcomed dialogue could help bring an end to months of deadly clashes between pro-Russia separatists and Ukrainian forces in the country's southeast. But much depends on the actions of one man, Russian President Vladimir Putin. VOA's Daniel Schearf reports from Moscow.
Video

Video Artists Shun Russia's Profanity Law

Russia in July enacted a law threatening fines for publicly displayed profanity in media, films, literature, music and theater. The restriction, the toughest since the Soviet era, aims to protect the Russian language and culture and has been welcomed by those who say cursing is getting out of control. But many artists reject the move as a patronizing and ineffective act of censorship in line with a string of conservative morality laws. VOA's Daniel Schearf reports from Moscow.
Video

Video British Fighters on Frontline of ISIS Information War

Security services are racing to identify the Islamic State militant who beheaded U.S. journalist James Foley in Syria. The murderer spoke English on camera with a British accent. It’s estimated that several hundred British citizens are fighting for the Islamic State, also called ISIL or ISIS, alongside thousands of other foreign jihadists. Henry Ridgwell reports for VOA from the center of the investigation in London.

AppleAndroid