Sea ice melts faster than expected

Discussion in 'Environment' started by Chris, Apr 5, 2009.

  1. Chris
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    Chris Gold Member

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    WASHINGTON (AP) — Arctic sea ice is melting so fast most of it could be gone in 30 years. A new analysis of changing conditions in the region, using complex computer models of weather and climate, says conditions that had been forecast by the end of the century could occur much sooner.

    A change in the amount of ice is important because the white surface reflects sunlight back into space. When ice is replaced by dark ocean water that sunlight can be absorbed, warming the water and increasing the warming of the planet.

    The finding adds to concern about climate change caused by human activities such as burning fossil fuels, a problem that has begun receiving more attention in the Obama administration and is part of the G20 discussions under way in London.

    "Due to the recent loss of sea ice, the 2005-2008 autumn central Arctic surface air temperatures were greater than 5 degrees Celsius (9 degrees Fahrenheit) above" what would be expected, the new study reports.

    That amount of temperature increase had been expected by the year 2070.

    The Associated Press: Study: Arctic sea ice melting faster than expected
     
  2. Old Rocks
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    Old Rocks Diamond Member

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    Which leads to this
    Melting Arctic Ocean Raises Threat of ‘Methane Time Bomb’ by Susan Q. Stranahan: Yale Environment 360


    Melting Arctic Ocean Raises Threat of ‘Methane Time Bomb’
    Scientists have long believed that thawing permafrost in Arctic soils could release huge amounts of methane, a potent greenhouse gas. Now they are watching with increasing concern as methane begins to bubble up from the bottom of the fast-melting Arctic Ocean.
    by susan q. stranahan

    For the past 15 years, scientists from Russia and other nations have ventured into the ice-bound and little-studied Arctic Ocean above Siberia to monitor the temperature and chemistry of the sea, including levels of methane, a potent greenhouse gas. Their scientific cruises on the shallow continental shelf occurred as sea ice in the Arctic Ocean was rapidly melting and as northern Siberia was earning the distinction — along with the North American Arctic and the western Antarctic Peninsula —of warming faster than any place on Earth.

    Until 2003, concentrations of methane had remained relatively stable in the Arctic Ocean and the atmosphere north of Siberia. But then they began to rise. This summer, scientists taking part in the six-week International Siberian Shelf Study discovered numerous areas, spread over thousands of square miles, where large quantities of methane — a gas with 20-times the heat-trapping power of carbon dioxide — rose from the once-frozen seabed floor.

    These “methane chimneys” sometimes contained concentrations of the gas 100 times higher than background levels and were so large that clouds of gas bubbles were detected "rising up through the water column," Orjan Gustafsson of the Department of Applied Environmental Science at Stockholm University and the co-leader of the expedition, said in an interview. There was no doubt, he said, that the methane was coming from sub-sea permafrost, indicating that the sea bottom might be melting and freeing up this potent greenhouse gas.
     
  3. Old Rocks
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    Old Rocks Diamond Member

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    This is the beginning of the nightmare feedback that has been haunting those that have studied this problem.

    The preliminary findings of the International Siberian Shelf Study 2008, being prepared for publication by the American Geophysical Union, are being overseen by Igor Semiletov of the Far-Eastern branch of the Russian Academy of Sciences. Since 1994, he has led about 10 expeditions in the Laptev Sea but during the 1990s he did not detect any elevated levels of methane. However, since 2003 he reported a rising number of methane "hotspots", which have now been confirmed using more sensitive instruments on board the Jacob Smirnitskyi.

    Dr Semiletov has suggested several possible reasons why methane is now being released from the Arctic, including the rising volume of relatively warmer water being discharged from Siberia's rivers due to the melting of the permafrost on the land.

    The Arctic region as a whole has seen a 4C rise in average temperatures over recent decades and a dramatic decline in the area of the Arctic Ocean covered by summer sea ice. Many scientists fear that the loss of sea ice could accelerate the warming trend because open ocean soaks up more heat from the sun than the reflective surface of an ice-covered sea.
    Exclusive: The methane time bomb - Climate Change, Environment - The Independent
     
  4. Old Rocks
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    More on the subject
    Melting Methane: A Storehouse of Greenhouse Gases Is Opening in Siberia - SPIEGEL ONLINE - News - International

    Shakhova and her colleagues gathered evidence for the loss of rigor in the frozen sea floor in a measuring campaign during the Siberian summer. The seawater proved to be "highly oversaturated with solute methane," reports Shakhova. In the air over the sea, greenhouse-gas content was measured in some places at five times normal values. "In helicopter flights over the delta of the Lena River, higher methane concentrations have been measured at altitudes as high as 1,800 meters," she says.

    The methane climate bomb is also ticking on land: A few years ago researchers noticed higher concentrations of methane in northern Siberia. The Siberian permafrost is known as one of the tipping points for the earth's climate, since the potent greenhouse gas develops wherever microorganisms decompose the huge masses of organic material from warmer eras that has been frozen here for thousands of years.

    "A Wake-Up Call for Science"

    Data from offshore drilling in the region, studied by experts at the Alfred Wegener Institute for Polar and Marine Research (AWI), also suggest that the situation has grown critical. AWI's results show that permafrost in the flat shelf is perilously close to thawing. Three to 12 kilometers from the coast, the temperature of sea sediment was -1 to -1.5 degrees Celsius, just below freezing. Permafrost on land, though, was as cold as -12.4 degrees Celsius. "That's a drastic difference and the best proof of a critical thermal status of the submarine permafrost," said Shakhova.
     
  5. Old Rocks
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  6. ItsFairmont
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    ItsFairmont Member

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    I like it.

    I can't stand cold weather. A tropical planet sounds great to me.


    Have any of you spent time in Hawaii? There's a reason people flock to it on vacations but not Minnesota.



    Sure, it sounds naive, but global warming is not a problem. Let it warm. Let's enjoy it.


    It's only people and animals that will suffer. The Earth itself will be just fine. And, as happened in the last 500 million years, species will come and go.


    You can't have a static climate. It's not possible.


    The earth will even it all out in the end. Relax.


    If I found out tomorrow that a big asteroid was headed toward earth and that we'd all die in a year, I'd say, "wow. Let's enjoy that last year."


    Take a deep breath, folks. This isn't our world. We're just another in a long line of temporary guests.
     
    Last edited: Apr 5, 2009
  7. elvis
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    elvis BANNED Supporting Member

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  8. Old Rocks
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  9. elvis
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    elvis BANNED Supporting Member

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  10. Sinatra
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    Sinatra Senior Member

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    Now that is what I'm talking about! :clap2:
     

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