Satellites reveal sudden Greenland ice melt

 
Nasa images reveal the extent of the  surface melt over Greenland’s ice sheet on July 8 (l) and July 12 (r) The first image shows Greenland's ice sheet on 8 July, the second, taken four days later, shows the area where ice has melted at the surface

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The surface of Greenland's massive ice sheet has melted this month over an unusually large area, Nasa has said.

Scientists said the "unprecedented" melting took place over a larger area than has been detected in three decades of satellite observation.

Melting even occurred at Greenland's coldest and highest place, Summit station.

The thawed ice area jumped from 40% of the ice sheet to 97% in just four days from 8 July.

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Melting events of this type occur about once every 150 years on average. With the last one happening in 1889, this event is right on time”

End Quote Lora Koenig Nasa Goddard Space Flight Center

Although about half of Greenland's ice sheet normally sees surface melting over the summer months, the speed and scale of this year's thaw surprised scientists, who described the phenomenon as "extraordinary".

Nasa said that nearly the entire ice cover of Greenland, from its thin, low-lying coastal edges to its centre, which is 3km (two miles) thick, experienced some degree of melting at its surface.

Until now, the most extensive melting seen by satellites in the past three decades was about 55% of the area.

According to ice core records, such pronounced melting at Summit station and across the ice sheet has not occurred since 1889.

"When we see melt in places that we haven't seen before, at least in a long period of time, it makes you sit up and ask what's happening," Nasa chief scientist Waleed Abdalati said.

"It's a big signal, the meaning of which we're going to sort out for years to come."

Watch this space

He said that, because this Greenland-wide melting has happened before - in 1889 - scientists are not yet able to determine whether this is a natural but rare event, or if it has been sparked by man-made climate change.

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The observation is in my view much more important than the recently reported break up of a large iceberg from Petermann Glacier”

End Quote Poul Christoffersen Scott Polar Research Institute

"Ice cores from Summit show that melting events of this type occur about once every 150 years on average. With the last one happening in 1889, this event is right on time," said Lora Koenig, a glaciologist from Nasa's Goddard Space Flight Center in Maryland and a member of the research team analysing the satellite data.

"But if we continue to observe melting events like this in upcoming years, it will be worrisome."

Prof Eric Wolff, from the British Antarctic Survey (Bas) told BBC News: "There have clearly been some very warm days in Greenland this month. As a result, the surface snow has melted across the whole ice sheet.

"This is confirmed by some of my international colleagues who are on the ground at the NEEM ice core drilling site in north Greenland - they are reporting several days with temperatures above zero, and ice layers forming in the snow.

"While this is very unusual, as always we cannot attribute any individual extreme event to climate change: We will have to wait and see if more such events occur in the next few years to understand its significance for both the climate and the health of the ice sheet."

Dr Poul Christoffersen, a glaciologist and engineer at the Scott Polar Institute in Cambridge, told BBC News: "The melting seen in the satellite data is unprecedented, as it extends all the way across the ice sheet including the summit, which is located 3,200 m above sea level. Melting is usually limited to less than 2000m elevation."

The news comes just days after Nasa satellite imagery revealed that a massive iceberg, twice the size of Manhattan, had broken off the Petermann Glacier in Greenland.

"The observation [from Greenland] is in my view much more important than the recently reported break up of a large iceberg from Petermann Glacier," Dr Christofferson added.

Nasa's Tom Wagner said: "This event, combined with other natural but uncommon phenomena, such as the large calving event last week on Petermann Glacier, are part of a complex story."

Scientists said they believed that much of Greenland's ice was already freezing again.

 

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  • rate this
    +2

    Comment number 580.

    562 Argent Pur - It's been answered numerous times but like all deniers you'll ignore it anyway. CO2 emissions from volcanoes caused the planet to gradually heat back up over millions of years, melting the ice.
    The difference between that and modern day, is that now we're seeing rapid warming in just a few decades, unprecedented in the planet's history. Likely cause: human intervention.

  • rate this
    -7

    Comment number 579.

    563 , 'climate change causes more extreme weather'

    really, why's that then?, I'd ask you to proove but you couldn't.

  • rate this
    -5

    Comment number 578.

    Brought to us by the liberal biased staff of BBC, this non-event deserves to be taken off off the news page. Lead page news?? I think not !! Once every 150 years the normal melt gets stronger. SO WHAT?! You cannot prove "global warming" as a reporter. And global warming is a periodic phenomenon that cannot be attributed to industrial activity. Get a grip people. You are making fools of yourselves.

  • rate this
    -1

    Comment number 577.

    I would be more worried about cutting down swathes of the Amazon ect which will make a difference when air quality drops and as a result billions die out. We are already seeing a lot of species of plants and animals gone because of humans.

    All this man made hype over warming just as an excuse to add more taxes needs knocking on the head. The dinosaurs thrived in the warm in their day..

  • rate this
    -2

    Comment number 576.

    People are egotistical. They think their tiny amount of time on Earth is of huge significance, whereas it isn't really, when you think that it's about 4.5 billion years old. I'm sure there have been many changes in the weather in that time. It's great to look after the planet, be as "green" as possible, but some people seem to need to "believe" or have faith in global warming like it's a religion.

  • rate this
    -5

    Comment number 575.

    30,000 years ago Britain was buried under 1km thick ice, as our Earth is a living organism it's fair to assume that it's happened before and will happen again, point is, are we polluting humans accelerating this natural cycle, problem is, we now know that evolving species can change radically in just a few generations, so it's possible that the great freeze could encroach within a very few years.

  • Comment number 574.

    This comment was removed because the moderators found it broke the house rules. Explain.

  • rate this
    -5

    Comment number 573.

    It's been proven through ice records that in the past the temperature increased and then the amount of CO2 in the atmosphere increased about 100 years after, this has been shown to be almost exact through a number of ice ages and melts. As such whilst mankind may not be helping matters the temperature will rise anyway. This was shown in the graphs Al Gore used himself in presentations.

  • rate this
    -3

    Comment number 572.

    524. Neil Smith
    Current av temp is 12-13c, so hugely less and current CO2 is also hugely less at around 400ppm. So there is a correlation and causation between increased CO2 in the atmosphere causing increased temps.

    I think that is called "cherry picking" data, something AGW disciples are prone to. In the Carboniferous period there was 3x today's CO2 and almost identical average temperature.

  • rate this
    +1

    Comment number 571.

    As satellite images are 'new' in terms of global climate change we dont know if this a regular(in geological time) melt and freeze scenario.
    Life on earth has been wiped out several times in the past when man was not around so it is not man alone which causes climate change or making a cause for the next extinction. Caution in what we do is right but trying to make us feel guilty for change...?

  • rate this
    +2

    Comment number 570.

    544.Nifton

    "Doesn't prove any corelation with global warming though..."

    It's hard to debate with ignorant people... Correlation aren't proven, it's worked out by statistics. What you meant was CAUSALITY!

  • rate this
    -5

    Comment number 569.

    How do we know they don't alter the 'photographs'. Knowing who owns NASA I wouldn't trust them as far as I could throw them! They are part of the NWO with hidden agendas.

  • rate this
    -1

    Comment number 568.

    Global warming being a myth or not is irrelevant
    Just look at hard facts & any fool can see that warmer interglacials cause extreme weather which are costly to the world wide economy
    Floods - Drought - Extreme storms that cause billions in damage are costing governments lot's of Tax Money to clean up
    Insurance claims increase & Insurance companies go bankrupt or raise premiums
    Think about it......

  • rate this
    +3

    Comment number 567.

    First time in my or my fathers lifetimes and I'm 59. It is at least an interesting event. I will watch with interest to see if it happens again in my life time then it will be really very very interesting.
    Devi Jankoit is only the surface ice that melted not the entire ice cap so don't get too excited. The minumum ice cover in the Arctic ocean in mid september could be quite dramatic this year

  • rate this
    -3

    Comment number 566.

    The only proven link is between man-made carbon dioxide, and government-made beurocracy and taxation.

  • rate this
    -3

    Comment number 565.

    As the article states, this melt is in line with historical records, so nothing untoward to worry about. Indeed, while temperature record graphs show an underlying trend, the actual temperature is very variable. Studies do show an underlying warming trend, while there has been an increase in extreme weather events over recent years. It's likely at least part of this is natural... (TBC)

  • rate this
    -2

    Comment number 564.

    PLN@546: I thought 'denier' had something to do with nylon stockings.....
    Another fine mesh you've gotten into!

  • rate this
    +1

    Comment number 563.

    558 Steven
    "Has the number of worldwide natural disasters actually increased as a result of climate change??"

    We can't tell yet. Only the dishonest few (like Al Gore) would ever claim certainty that climate change has brought about more natural disasters.
    It is however true that climate change will cause more extreme weather, but you can't link an individual case to climate change.

  • rate this
    -3

    Comment number 562.

    To the people who marked my comment at 529 down, why not try and answer the question instead.

    "Without man made carbon emissions, how did the planet warm up enough to melt miles of ice on its surface and end the last ice age ?"

    It's a perfectly reasonable question and we would all like to hear the wisdom of your answers.

  • rate this
    -1

    Comment number 561.

    524.Neil Smith
    "So there is a correlation and causation between increased CO2 in the atmosphere causing increased temps."

    Only in recent times, but if you look at the relationship over Geological timescales (hundreds of millions of years) it isn't a very good correlation...

 

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