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. bignevermo

    Let's see, 2012 – 150 would put it at 1939. That means Global Warming started when the Carter went to war with Nevada"

    lets see that would make Penn State not so good a college to go to if you think 150 years ago is 1939...
    just sayin!

    July 25, 2012 at 1:37 pm | Report abuse |
    • snowdogg

      "the last such melt happened in 1889"

      July 25, 2012 at 1:44 pm | Report abuse |
    • InCanada

      2012-150=1862. Am I missing something?

      July 25, 2012 at 1:46 pm | Report abuse |
    • mike

      Nice mathematics. lol

      July 25, 2012 at 1:58 pm | Report abuse |
    • TonyInNYC

      "once in about every 150 years" is not the same as "150 years ago"

      July 25, 2012 at 2:07 pm | Report abuse |
    • sam

      what kind of math were you just doing there... 1939 wth?!?!? more like 150 years from 1889 like it says in the article which would put that cycle at 2039. America, where we can't do math good, or any edumacation subject good...pitiful

      July 25, 2012 at 2:11 pm | Report abuse |
    • John

      These types of meltings happen, ON AVERAGE, every 150 years. The last such one to happen was in 1889. To anyone that refuses to think, this means that this melt and the last one like it happened sooner to each other than average.


      July 25, 2012 at 2:14 pm | Report abuse |
    • scientist

      the average is 150 years, this round happened to be less than the average amount of time, if anything it is a sign that global warming is speeding up the process

      July 25, 2012 at 2:22 pm | Report abuse |
    • LynnElla

      Note the word "about" – not "exactly" but "about"

      July 25, 2012 at 2:24 pm | Report abuse |
  2. Green -Shawn

    This is global warming people. Someone needs to do something about it. Everyone needs to voice themselves.

    The 3rd paragraph in this artical is crap. This is a lie this is really contributed to the Global Warming we are seeing all over the planet. Look what just happened in China with the floods. Look at all the record high temps in the US so far this year. 2005 was the warmest on record and we crushed that this 2012.
    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.

    Please for all man kind REDUCE YOUR CARBON FOOTPRINT. Spread the word. Not government not scientists no is going to do this for you. Have we been so blind the last 20 years to ignore the problem or just blatant ignorant to the planet.

    July 25, 2012 at 1:38 pm | Report abuse |
    • SgtSerge

      And you are just going to leave out the core samples???? the facts is happens about every 150 years does not mean anything?

      Wow, you make us people that try and educate people on the real issues look so dumb.

      July 25, 2012 at 1:43 pm | Report abuse |
    • ladyfonseca

      Hey Greenie, The Earth has been warming since the ice age, otherwise we would living in igloos. You CANNOT stop global warming from occuring. If it is because of our "carbon footprint" why were floods, blizzards and other catastrophic weather events happening long before gas guzzeling cars, electricity, and other forms of pollution were invented?

      July 25, 2012 at 1:49 pm | Report abuse |
    • oldpatriot

      Fools will never give it up, if it happens every 150 years as stated then it cannot be global warming because it supposedly only impacts the last 200 years, to have ice based evidence of regular ice melts on a `50 year cycle shows that its not increasing, its not more frequent and its not global warming.

      It is nothing but natural weather variations.

      July 25, 2012 at 1:49 pm | Report abuse |
    • biologixco

      blah blah blah.
      For every American trying to do the right thing, there are 3 chinese and 2 indians doing their best to UNDO any effort you just made. Its a lost cause. I wouldn't even worry about it. Chicken Littles come out of the woodwork every time it gets hot, or there's a drought.

      July 25, 2012 at 1:51 pm | Report abuse |
    • Allen

      I don't dispute the possibility of global warming. I would argue that mother nature has its own quirks. Like mini ice ages, solar storms, and reverse polarization. To say that Mother Nature has no say in the increase in temperature is a very dangerous statement, and I would say that your strong opinion about mankind's influence may be a little over stated. But I do believe that we should look into technology to reduce or reverse the carbon footprint mankind is leaving. But to ask everyone in the world to change their behavior is egotistical and impossible. People will do what they know, and what they need to do to survive.

      July 25, 2012 at 2:16 pm | Report abuse |
  3. SgtSerge

    Climate change is real, the question is are we causing it or is it natural.
    Without baseline metrics of the natual climate change model we can never really see what our impact is.
    It is anti-climate change it is rational and letting scientists to the job.
    Pretty simple they release the data as they find it, some says one thing, others say another. Hence why we need baseline metrics to even start to answer this puzzle.

    July 25, 2012 at 1:40 pm | Report abuse |
    • conrad

      A warming world isn't the only reason to reduce our carbon footprint. We are polluting the planet to such a degree that it is not inhabitable; this is already true in many areas particularly waterways which cannot support acquatic or avian life.

      July 25, 2012 at 2:24 pm | Report abuse |
  4. snowdogg

    "Greenland has lost 150 gigatons of ice per year over the last 20 years"

    That is a LOT of margaritas!!!

    July 25, 2012 at 1:42 pm | Report abuse |
  5. Jeff

    Roger, what evidence. Could you please enumerate the evidence? Here is a link to a good longterm view of global. These might help alleviate some anxiety related to this topic.

    July 25, 2012 at 1:46 pm | Report abuse |
  6. lupus

    Flat earthers were quaint and their beliefs never harmed anyone. Climate change denialists will kill us all.

    July 25, 2012 at 1:48 pm | Report abuse |
    • James

      Tell it to those who were burned at the stake for suggesting otherwise.

      July 25, 2012 at 1:52 pm | Report abuse |
  7. Photographed Rorschach Test

    i see salmon on ice...on the left...and thawed salmon...on the right...

    July 25, 2012 at 1:49 pm | Report abuse |
    • Hope


      If you only knew...


      Build a sanctuary...


      July 25, 2012 at 1:59 pm | Report abuse |
  8. SgtSerge

    Lupus...... I have no idea what you are trying to say but but "Climate change denialists will kill us all." makes anyone who is trying to educate people on this very tough. The sky is not falling, but getting a baseline metric to the natural long term climate history will go a long way in finding out how we impact our environment. That is not a denial, it is how things have to work. No one knows.... NO ONE. That is the point we need to find out.

    July 25, 2012 at 1:51 pm | Report abuse |
  9. MAD

    Let me know when it's over 9000

    Until then, I'll be driving my hummer and eating shark fin soup.

    July 25, 2012 at 1:51 pm | Report abuse |
  10. james ainoris

    Big oil and coal politicizes this most critical issue... lets switch off lush dimbaugh and al gore and look only at the science.. question how many people cars planes trains ships airconditioners oil heat coal and gas power plants cows farmland tractors bachoes and people existed before 1900ce? Is it resonable to postulate that the addition of all the pollution from said above devices may effect earths natural cyclic swing of ocean temp? The last time this happened (1880s) the co 2 level was 40% lower (see ice air bubble testing varifying increase since industrial revolution) .... no one wants to stop first! currently china and india pump out huge amounts exceeding america and europe... I hope the scientists are wrong for my childrens sake..remmeber the ozone layer... disputed by knuckleheads also as a "liberal conspiracy " in the 70s. G-d save us from politics... james ainoris

    July 25, 2012 at 1:54 pm | Report abuse |
    • Hope


      July 25, 2012 at 2:04 pm | Report abuse |
    • BigHwasdemo

      The extra CO2 will just get sucked up by the more warm and lush tropical vegetation. Just give it a little time and we won't need to import bananas or coconuts. But we may be buying more corn and wheat from Canada. Wouldn't 85 degree water be nice in Nantucket?

      July 25, 2012 at 2:18 pm | Report abuse |
  11. Grey

    So 123 years ago they had global warming? Must have been all the horse manure.

    July 25, 2012 at 1:57 pm | Report abuse |
  12. BigHwasdemo

    Apparently this will open up some nice ocean front property, resorts with skiing year round.

    July 25, 2012 at 2:10 pm | Report abuse |
  13. millarddjr


    do you really believe that chart? Written by two people with no formal training in climatology, based on records from a defunct organization that only existed for 30 years, that can only be found referenced on deeply religious sites?

    Please. If you're going to make an argument against climate change, fine. But please use real data.

    July 25, 2012 at 2:11 pm | Report abuse |
  14. NeoGraphix

    I thinking it might be a good retirement area in 20 years or so.

    July 25, 2012 at 2:14 pm | Report abuse |
  15. xfiler93

    more global warming hype by CNN and the hoaxers. this is not RARE or unprecedented.

    July 25, 2012 at 2:26 pm | Report abuse |
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