News / Science & Technology

    Study: Greenland Ice Less Vulnerable Than Feared to Thaw

    Icebergs are reflected in the calm waters at the mouth of the Jakobshavn ice fjord near Ilulissat in Greenland. (file photo)
    Icebergs are reflected in the calm waters at the mouth of the Jakobshavn ice fjord near Ilulissat in Greenland. (file photo)
    Reuters
    Greenland is less vulnerable than expected to a runaway melt that would drive up world sea levels, according to scientists who found that only a quarter of the ice sheet thawed in a warm period more than 100,000 years ago.
        
    The study, involving 300 experts from 14 nations, implied that Antarctica at the other end of the planet would contribute at least as much or more to the kind of sea level rise that threatens coasts and cities from Mumbai to Miami.
        
    Climate scientists are struggling to understand the risks of a melt of the vast ice stores of Greenland and Antarctica to help plan coastal protection. Sea levels rose about 17 cm (7 inches) in the past century and the rate has quickened.
        
    Examination of ice from a 2.5 km- (1.5 mile-) deep ice core in northwest Greenland indicated that its ice sheet lost only about 400 meters (1,300 ft) in thickness in the early part of the Eemian, a warm period from about 130,000 to 115,000 years ago.
        
    They estimated it lost about a quarter of its ice overall, according to a study published in Thursday's edition of the journal Nature.

    "The volume of ice lost from the Greenland ice sheet was more moderate than many had expected,'' lead author Dorthe Dahl-Jensen, a professor at the University of Copenhagen, told Reuters.
        
    Some past studies have suggested that Greenland may be poised for an irreversible melt due to climate change, blamed by a U.N. panel of experts on use of fossil fuels in nations led by China, the United States, India and Russia.

    The limited size of the melt was also a surprise because the scientists found that Eemian temperatures, inferred from chemicals in air bubbles trapped in the ice, were higher than expected at 8 degrees Celsius (14 Fahrenheit) above current levels.
        
    Fossil fuels

    "We'll probably reach the Eemian temperatures within the next 100 years,'' Dahl-Jensen said. The Arctic region is warming at one of the fastest rates on the planet; global warming of 2 or 3 degrees Celsius (3.6 to 5.4 F) might trigger an 8 degrees C rise in Greenland.
        
    The United Nations panel of climate scientists has said that sea levels may rise by between 18 and 59 cm (7-24 inches) this century, or by more if a thaw of Greenland or Antarctica speeds up. Elsewhere, it expects more floods, droughts and heatwaves.
        
    And there are already signs of Eemian-style conditions. In July 2012, almost the entire surface of Greenland was covered in melt water, an event witnessed by the scientists from the United States, Canada, France, Germany, Britain, Japan, South Korea and elsewhere.

    "It even rained in our camp,'' Dahl-Jensen said.

    Ice cores build up from annual snowfall and can be read like tree rings to judge their age. The Eemian warmth was probably caused by natural shifts in the Earth's orbit around the sun.

    The scientists estimated that Greenland contributed only about 2 meters to sea level rise of between 4 and 8 meters during the Eemian.
        
    That meant that at least half and perhaps much more of the melt water came from Antarctica, the planet's other big store of land ice, which, unlike the floating ice of the Arctic, causes the sea level to rise when it melts.
        
    As yet, there has been no study of cores from the crucial West Antarctic ice sheet equivalent to the Greenland research.

    You May Like

    US Leaders Who Served in Vietnam War Look Back and Ahead

    In New York Times opinion piece, Secretary of State John Kerry, Senator John McCain and former Senator Bob Kerrey say as US strengthens relations with Vietnam, it is important to remember lessons learned from war

    Who Are US Allies in Fight Against Islamic State?

    There is little but opportunism keeping coalition together analysts warn — SDFs Arab militias are not united even among themselves, frequently squabble and don’t share Kurds' vision for post-Assad Syria

    Learning Foreign Language Helps US Soldiers Bridge Culture Gap

    Effective interaction with local populations part of everyday curriculum at Monterey, California, Defense Language Institute

    Featured Videos

    Your JavaScript is turned off or you have an old version of Adobe's Flash Player. Get the latest Flash player.
    Vietnamese-American Youth Optimistic About Obama's Visit to Vietnami
    X
    Elizabeth Lee
    May 22, 2016 6:04 AM
    U.S. President Barack Obama's visit to Vietnam later this month comes at a time when Vietnam is seeking stronger ties with the United States. Many Vietnamese Americans, especially the younger generation, are optimistic Obama’s trip will help further reconciliation between the two former foes. Elizabeth Lee has more from the community called "Little Saigon" located south of Los Angeles.
    Video

    Video Vietnamese-American Youth Optimistic About Obama's Visit to Vietnam

    U.S. President Barack Obama's visit to Vietnam later this month comes at a time when Vietnam is seeking stronger ties with the United States. Many Vietnamese Americans, especially the younger generation, are optimistic Obama’s trip will help further reconciliation between the two former foes. Elizabeth Lee has more from the community called "Little Saigon" located south of Los Angeles.
    Video

    Video First-generation, Afghan-American Student Sets Sights on Basketball Glory

    Their parents are immigrants to the United States. They are kids who live between two worlds -- their parents' homeland and the U.S. For many of them, they feel most "American" at school. It can be tricky balancing both worlds. In this report, produced by Beth Mendelson, Arash Arabasadi tells us about one Afghan-American student who seems to be coping -- one shot at a time.
    Video

    Video Newest US Citizens, Writing the Next Great Chapter

    While universities across the United States honor their newest graduates this Friday, many immigrants in downtown Manhattan are celebrating, too. One hundred of them, representing 31 countries across four continents, graduated as U.S. citizens, joining the ranks of 680,000 others every year in New York and cities around the country.
    Video

    Video Vietnam Sees Strong Economic Growth Despite Incomplete Reforms

    Vietnam has transformed its communist economy to become one of the world's fastest-growing nations. While the reforms are incomplete, multinational corporations see a profitable future in Vietnam and have made major investments -- as VOA's Jim Randle reports.
    Video

    Video Qatar Denies World Cup Corruption

    The head of Qatar’s organizing committee for the 2022 World Cup insists his country's bid to host the soccer tournament was completely clean, despite the corruption scandals that have rocked the sport’s governing body, FIFA. Hassan Al-Thawadi also said new laws would offer protection to migrants working on World Cup construction projects. VOA's Henry Ridgwell reports.
    Video

    Video Infrastructure Funding Puts Cambodia on Front Line of International Politics

    When leaders of the world’s seven most developed economies meet in Japan next week, demands for infrastructure investment world wide will be high on the agenda. Japanese Prime Minister Shinzo Abe’s push for “quality infrastructure investment” throughout Asia has been widely viewed as a counter to the rise of Chinese investment flooding into region.
    Video

    Video Democrats Fear Party Unity a Casualty in Clinton-Sanders Battle

    Democratic presidential front-runner Hillary Clinton claimed a narrow victory in Tuesday's Kentucky primary even as rival Bernie Sanders won in Oregon. Tensions between the two campaigns are rising, prompting fears that the party will have a difficult time unifying to face the presumptive Republican nominee, Donald Trump. VOA national correspondent Jim Malone has more from Washington.
    Video

    Video Portrait of a Transgender Marriage: Husband and Wife Navigate New Roles

    As controversy continues in North Carolina over the use of public bathrooms by transgender individuals, personal struggles with gender identity that were once secret are now coming to light. VOA’s Tina Trinh explored the ramifications for one couple as part of trans.formation, a series of stories on transgender issues.
    Video

    Video Amerikan Hero Flips Stereotype of Middle Eastern Character

    An Iranian American comedian is hoping to connect with American audiences through a film that inverts some of Hollywood's stereotypes about Middle Eastern characters. Sama Dizayee reports.
    Video

    Video Budding Young Inventors Tackle City's Problems with 3-D Printing

    Every city has problems, and local officials and politicians are often frustrated by their inability to solve them. But surprising solutions can come from unexpected places. Students in Baltimore. Maryland, took up the challenge to solve problems they identified in their city, and came up with projects and products to make a difference. VOA's June Soh has more on a digital fabrication competition primarily focused on 3-D design and printing. Carol Pearson narrates.

    Special Report

    Adrift The Invisible African Diaspora