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

India PM Modi's Party Distances Itself From Religious Conversions

BJP under fire for being slow to rein in hardline affiliate groups allegedly trying to promote Hindu-dominant agenda by luring Muslims and Christians to convert More

Anti-Whaling Group Found in Contempt of Court

Radical environmentalists who threw acid and smoke bombs at Japanese whalers in the waters off Antarctica continue their campaign to disrupt Japan's annual whale hunt More

UN's Ban Urges End to Discrimination Against Ebola Workers

Ban was speaking in Guinea on the second day of a whistle-stop tour aimed at thanking healthcare workers of the countries at the heart of the epidemic 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.
US Decision on Cuba Underscores Divisions Among Miami Cubansi
X
Sharon Behn
December 19, 2014 9:34 PM
For decades, older, more conservative Cubans have been gathering at Café Versailles on the corner of Calle Ocho to eat Cuban food and talk politics. After hearing of President Barack Obama’s decision, a number of them gathered in front of the café with posters to protest. VOA's Sharon Behn reports on the situation.
Video

Video US Decision on Cuba Underscores Divisions Among Miami Cubans

For decades, older, more conservative Cubans have been gathering at Café Versailles on the corner of Calle Ocho to eat Cuban food and talk politics. After hearing of President Barack Obama’s decision, a number of them gathered in front of the café with posters to protest. VOA's Sharon Behn reports on the situation.
Video

Video Three Cities Bid for Future Obama Presidential Library

President Barack Obama still has two years left in his term in office, but the effort to establish his post-presidential library is already underway. The bid for the Obama Presidential Library is down to four locations in three states -- New York, Hawaii, and Illinois. As VOA’s Kane Farabaugh reports, each of them played an important part in the president’s life before he reached the White House.
Video

Video Cuba Deal is Major Victory for Pope’s Diplomatic Initiatives

Pope Francis played a key role in brokering the US-Cuba deal that was made public earlier this week. It is the most stunning success so far in a series of peacemaking efforts by the pontiff. VOA religion reporter Jerome Socolovsky has more.
Video

Video Fears of More Political Gridlock in 2015

2014 proved to be a difficult year politically for President Barack Obama and a very good year for the U.S. Republican Party. Republican gains in the November midterm elections gave them control of the Senate and House of Representatives for the next two years -- setting the stage for more confrontation and gridlock in the final two years of the Obama presidency. VOA National Correspondent Jim Malone has a preview from Washington.
Video

Video Sudan School Becomes Target of Aerial Attacks

The school dropout rate is at an all-time high in Sudan's South Kordofan state because many schools have been destroyed during the three-year civil war between the government and SPLA-N rebel forces. Adam Bailes visited Sudan's Nuba Mountains' region and reports many children are simply too scared to go to school
Video

Video VOA Reporter Tours Devastated Peshawar School

Islamist militants wearing military uniforms and strapped with explosives attacked a military run school Tuesday in the northwestern Pakistani city of Peshawar. At least 141 people were killed in the horrific attack, most of them young students. VOA reporter Ayaz Gul visited the devastated school and attended the funeral of the principal who courageously tried to save her students from the deadly attack.
Video

Video Nigerians Fleeing Boko Haram Languish in Camp Near Capital

In its five-year effort to impose Islamic law in northeastern Nigeria, the Boko Haram extremist group has killed thousands of people and forced hundreds of thousands to flee. Some of those who ran for their lives now live in squalor on the edges of the capital, Abuja. Chris Stein reports for VOA.
Video

Video Aceh Rebuilt Decade After Tsunami, But Scars Remain

On December 26, 2004 there was an earthquake in the Indian Ocean so powerful it caused the Earth’s axis to wobble a few centimeters. Onshore on the island of Sumatra, the resulting tsunami was devastating. A decade later, VOA Correspondent Steve Herman reports from Banda Aceh, Indonesia, where although there is little remaining evidence of the physical devastation, the psychological scars among survivors remain.

All About America

AppleAndroid