Satellites reveal rare levels of Greenland ice melt
Satellite data show Greenland surface melt on July 8, left, and July 12. "Melt" is dark pink; "probable melt" is light pink.
July 25th, 2012
12:40 PM ET

Satellites reveal rare levels of Greenland ice melt

Nearly all of Greenland’s ice cover at least temporarily melted at the surface during an unusually warm stretch in mid-July - a level of melting not seen there in 123 years, NASA said.

In an average summer, melting happens on about half of the surface of Greenland’s ice sheet, which covers most of the land and is an average 1 mile thick.

But an unusually strong ridge of relatively warm air - hovering just above freezing for several hours at the highest elevation - rapidly accelerated melting this month, and satellites showed that an estimated 97% of the surface had melted at some point by July 12, NASA said.

While some of that melt water freezes in place, some of it is lost to rivers and the ocean – and mid-July’s melting caused river flooding that threatened a number of bridges, said Tom Wagner, NASA’s cryosphere program manager in Washington. (The flooding has been captured on a number of YouTube videos, including this one.)

Where this falls in the larger context of Greenland’s changing ice cap - scientists say it is shrinking and causing ocean levels to rise, with warming ocean waters causing ice on the periphery to be lost through melting and rapid flow - is a complicated question, NASA says.

Ice core samples show that the surface melting seen this July happens once in about every 150 years, and the last such melt happened in 1889, NASA said.

“It could be that this melt event is caused by normal variations that just happen once in a while,” Wagner said by phone Tuesday.

So, Wagner said, one can’t attribute July’s melting to global warming, but the melting must be digested with this in mind: that "warming is causing the loss of ice all over Greenland, and the Greenland ice sheet is shrinking."

Wagner said Greenland has lost 150 gigatons of ice per year over the last 20 years, and its shrinking cap contributes up to half a millimeter a year to global sea-level rise. Researchers haven’t determined how much of mid-July’s melt refroze or went into the ocean, NASA said.

The July 8-12 melting happened days before an island of ice twice the size of Manhattan broke off from Greenland’s Petermann Glacier on July 16. But with glacier calving attributed to ocean temperature, not the more quickly fluctuating air temperature, no one is linking the calving to July’s melting of surface ice, Wagner said.

July’s melting "combined with other natural but uncommon phenomena, such as the large calving event last week on Petermann Glacier, are part of a complex story,” Wagner said in a news release. “Satellite observations are helping us understand how events like these may relate to one another as well as to the broader climate system.”

July’s melting was detected by three satellites - the Indian Space Research Organization’s Oceansat-2, and NASA’s Terra and Aqua.

July 18, 2012: Massive ice island breaks off Greenland glacier

May 4, 2012: Greenland ice melt could raise seas less than feared, study says

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Filed under: Greenland • Science • Weather
soundoff (263 Responses)
  1. JibbaJabba

    Good thing climate change is just a liberal conspiracy. Otherwise I'd be worried.

    July 25, 2012 at 4:36 pm | Report abuse |
    • Bill

      I think we should fine the Greenlanders for their melting ice. We can use the money to install air conditioners in the tropics. Global warming solved.

      July 25, 2012 at 4:55 pm | Report abuse |
  2. Dirka

    God must really hate ice these days

    July 25, 2012 at 4:43 pm | Report abuse |
    • esoll

      What god has to do anything with ice melting. Warm air does.

      July 25, 2012 at 5:03 pm | Report abuse |
  3. Captain Obvious

    On the bright side, it'll be much easier to drill for oil with all that ice out of the way.

    July 25, 2012 at 4:45 pm | Report abuse |
  4. jtucker4

    "Ice core samples show that the surface melting seen this July happens once in about every 150 years, and the last such melt happened in 1889, NASA said."

    So if it happens again next year we know we're screwed.

    July 25, 2012 at 4:45 pm | Report abuse |
    • skookumchuck

      Good reasoning. The denialists must hate the fact that the scientists studying this melt are being very honest. They like to claim they pick their conclusions to follow the herd and get research money. In reality, the scientists are much more honest that the oil lobby denialists.

      July 25, 2012 at 4:53 pm | Report abuse |
    • Hope

      It's been going on for quite some time!!!

      What's EXTRAORDINARÉ

      Is the heat, sitting there!

      Phew!

      HOT...

      🙂

      Now, THAT'S moving mountain.

      ~Blessings abound~

      😀

      July 27, 2012 at 6:33 pm | Report abuse |
  5. WE ARE STILL PENN STATE

    The Good Lord is punishing the world for turning their backs on our most beloved center for learning and humanity. how DARE you all point fingers and laugh over false accusations against Penn State while you wallow in your own filth. I'm sorry your Communications Degree from Ohio State doesn't mean jack squat. God is already punishing you for your failures by making you live in Cleveland!

    July 25, 2012 at 4:49 pm | Report abuse |
    • twotwotango

      Damn take your meds Mr. We Are Penn State. Why would you comment such an absurd thing on a global warming article? SMH

      July 25, 2012 at 4:55 pm | Report abuse |
    • Thezel

      Time to take a ride on the SS Sundusky, sonny.

      July 25, 2012 at 5:36 pm | Report abuse |
  6. neoritter

    People need to remember that when the Vikings found and first colonized Greenland, the place was "green". They happened to land and settle during one of these melting periods.

    July 25, 2012 at 4:51 pm | Report abuse |
    • MrApplesauce

      Uhm. Actually it was just propaganda back then to get more people to settle there.

      July 25, 2012 at 4:56 pm | Report abuse |
    • rosie

      Greenland has never been totally green during human existence. There are places that have vegetation but the whole island has never been devoid of ice, except possibly when the Arctic was a tropical forest, but that was a few million years ago.

      July 25, 2012 at 5:02 pm | Report abuse |
    • tmac

      It was named that to lure settlers away from iceland... check your facts

      July 25, 2012 at 5:08 pm | Report abuse |
    • sean

      not it wasn't, they just named it that to entice others to come there.

      July 25, 2012 at 5:11 pm | Report abuse |
    • neoritter

      You're right it wasn't totally green, but fair sized portions were. Interpretation of ice core and clam shell data suggests that between 800 and 1300 CE the regions around the fjords of southern Greenland experienced a relatively mild climate several degrees Celsius higher than usual in the North Atlantic, with trees and herbaceous plants growing and livestock being farmed. Barley was grown as a crop up to the 70th parallel. What is verifiable is that the ice cores indicate Greenland has experienced dramatic temperature shifts many times over the past 100,000 years. Basically Greenland had quite a bit less glaciers a few hundred years ago.

      July 25, 2012 at 5:21 pm | Report abuse |
    • neoritter

      Also, I never said that's why it was called Greenland. Check your reading comprehension.

      July 25, 2012 at 5:23 pm | Report abuse |
    • Olaf Big

      Some coastal areas were and still are green in the summer. Greenland's interior was never green on human memory. As the article points out, the ice shield is one mile thick, and it certainly has not grown that thick in the last one thousand years.

      July 25, 2012 at 5:42 pm | Report abuse |
  7. Alexander

    Actually scientists say we live in a short warm period between ice ages in which entire human civilization occurred. The next ice age is just around the corner if we talking n geological time scale so people just pls enjoy the warmth while you still have the time. Next ice age will be tough and will last for at least 10000 years.

    July 25, 2012 at 4:58 pm | Report abuse |
    • skookumchuck

      Don't be afraid. Global warming will flood the coastal cities of the USA and turn the agrcultural zones into deserts lomg before another ice age happens.

      July 25, 2012 at 5:06 pm | Report abuse |
  8. DV

    neoritter, they called it Greenland to entice settlers, not because it had no ice cap

    July 25, 2012 at 4:58 pm | Report abuse |
  9. Alex

    To bad we can't somehow transport that huge glacier that broke off to the areas in the U.S. suffering from drought.

    July 25, 2012 at 5:04 pm | Report abuse |
  10. tmac

    You're from Texas... Your opinion doesn't count when you come from a state that attempted to remove Thomas Jefferson from its High School curriculum.

    July 25, 2012 at 5:12 pm | Report abuse |
    • MosesHorwitz

      But TJ put his thingy in a blacky! How shameful!

      July 25, 2012 at 6:24 pm | Report abuse |
  11. HIDE BEHIND

    Data source please as to temperatures being higher 1200 years ago?
    There was a much drier period during the twelth century true but I cannot find any scientific studies that show higher temperatures.
    Just the opposite in fact, average mean temperatures in 4-5°F below present period as of 2007-2008. seems norm.
    It is the higher temperature today and its rate of increase that has vlimatologist so concerned about our present drought conditions here and around globe.
    As too tipping of Magnetic North while this too has happened in past, including almost or complete reversals in its fields but, there has also been an increase in rate of that tipping within last few years.
    From personal perspective, what an interesting time I live within.

    July 25, 2012 at 5:14 pm | Report abuse |
  12. marcia

    you are absolutely correct and in line with most scientists findings today. We are on the verge of a small ice age.

    July 25, 2012 at 5:15 pm | Report abuse |
    • skookumchuck

      Sure Marcia, and peace is breaking out all over the world and the USA's economic future looks bright.

      July 25, 2012 at 5:22 pm | Report abuse |
    • normsw

      She's right, dumbo. Look back at the 1880s, when all of Europe & most of the northern hemisphere was locked in a mini-ice age.Try looking up historical facts before you run off at the brain.

      July 26, 2012 at 5:18 am | Report abuse |
  13. Dan

    Greenland's ice melted? And low-lying seaside cities didn't flood into oblivion? Shock.

    July 25, 2012 at 5:26 pm | Report abuse |
    • sqeptiq

      Read the article. There was some melting pretty much everywhere, not melt out.

      July 25, 2012 at 5:44 pm | Report abuse |
  14. skookumchuck

    Cooling the Warming Debate: Major New Analysis Confirms That Global Warming Is Real

    ScienceDaily (Oct. 21, 2011) — Global warming is real, according to a major study released Oct. 20. Despite issues raised by climate change skeptics, the Berkeley Earth Surface Temperature study finds reliable evidence of a rise in the average world land temperature of approximately 1°C since the mid-1950s.

    July 25, 2012 at 5:27 pm | Report abuse |
  15. Hope

    The ENVIRONUTS as you call them aren't concerned about the carbon footprint of the U.S. as much as they are other countries like Dubai who's small area produces THRICE the carbon of the U.S. and China who don't have enviroNUTS. Just sayin'.

    July 25, 2012 at 5:30 pm | Report abuse |
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