Global warming 'past the point of no return'

Discussion in 'Lounge' started by Krell, Sep 17, 2005.

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  1. Krell

    Krell worthless dirtball Expert

    By Steve Connor, Science Editor

    Published: 16 September 2005



    A record loss of sea ice in the Arctic this summer has convinced scientists that the northern hemisphere may have crossed a critical threshold beyond which the climate may never recover. Scientists fear that the Arctic has now entered an irreversible phase of warming which will accelerate the loss of the polar sea ice that has helped to keep the climate stable for thousands of years.

    They believe global warming is melting Arctic ice so rapidly that the region is beginning to absorb more heat from the sun, causing the ice to melt still further and so reinforcing a vicious cycle of melting and heating.

    The greatest fear is that the Arctic has reached a "tipping point" beyond which nothing can reverse the continual loss of sea ice and with it the massive land glaciers of Greenland, which will raise sea levels dramatically.

    Satellites monitoring the Arctic have found that the extent of the sea ice this August has reached its lowest monthly point on record, dipping an unprecedented 18.2 per cent below the long-term average.

    Experts believe that such a loss of Arctic sea ice in summer has not occurred in hundreds and possibly thousands of years. It is the fourth year in a row that the sea ice in August has fallen below the monthly downward trend - a clear sign that melting has accelerated.

    Scientists are now preparing to report a record loss of Arctic sea ice for September, when the surface area covered by the ice traditionally reaches its minimum extent at the end of the summer melting period.

    Sea ice naturally melts in summer and reforms in winter but for the first time on record this annual rebound did not occur last winter when the ice of the Arctic failed to recover significantly.

    Arctic specialists at the US National Snow and Ice Data Centre at Colorado University, who have documented the gradual loss of polar sea ice since 1978, believe that a more dramatic melt began about four years ago.

    In September 2002 the sea ice coverage of the Arctic reached its lowest level in recorded history. Such lows have normally been followed the next year by a rebound to more normal levels, but this did not occur in the summers of either 2003 or 2004. This summer has been even worse. The surface area covered by sea ice was at a record monthly minimum for each of the summer months - June, July and now August.

    Scientists analysing the latest satellite data for September - the traditional minimum extent for each summer - are preparing to announce a significant shift in the stability of the Arctic sea ice, the northern hemisphere's major "heat sink" that moderates climatic extremes.

    "The changes we've seen in the Arctic over the past few decades are nothing short of remarkable," said Mark Serreze, one of the scientists at the Snow and Ice Data Centre who monitor Arctic sea ice.

    Scientists at the data centre are bracing themselves for the 2005 annual minimum, which is expected to be reached in mid-September, when another record loss is forecast. A major announcement is scheduled for 20 September. "It looks like we're going to exceed it or be real close one way or the other. It is probably going to be at least as comparable to September 2002," Dr Serreze said.

    "This will be four Septembers in a row that we've seen a downward trend. The feeling is we are reaching a tipping point or threshold beyond which sea ice will not recover."

    The extent of the sea ice in September is the most valuable indicator of its health. This year's record melt means that more of the long-term ice formed over many winters - so called multi-year ice - has disappeared than at any time in recorded history.

    Sea ice floats on the surface of the Arctic Ocean and its neighbouring seas and normally covers an area of some 7 million square kilometres (2.4 million square miles) during September - about the size of Australia. However, in September 2002, this dwindled to about 2 million square miles - 16 per cent below average.

    Sea ice data for August closely mirrors that for September and last month's record low - 18.2 per cent below the monthly average - strongly suggests that this September will see the smallest coverage of Arctic sea ice ever recorded.

    As more and more sea ice is lost during the summer, greater expanses of open ocean are exposed to the sun which increases the rate at which heat is absorbed in the Arctic region, Dr Serreze said.

    Sea ice reflects up to 80 per cent of sunlight hitting it but this "albedo effect" is mostly lost when the sea is uncovered. "We've exposed all this dark ocean to the sun's heat so that the overall heat content increases," he explained.

    Current computer models suggest that the Arctic will be entirely ice-free during summer by the year 2070 but some scientists now believe that even this dire prediction may be over-optimistic, said Professor Peter Wadhams, an Arctic ice specialist at Cambridge University.

    "When the ice becomes so thin it breaks up mechanically rather than thermodynamically. So these predictions may well be on the over-optimistic side," he said.

    As the sea ice melts, and more of the sun's energy is absorbed by the exposed ocean, a positive feedback is created leading to the loss of yet more ice, Professor Wadhams said.

    "If anything we may be underestimating the dangers. The computer models may not take into account collaborative positive feedback," he said.

    Sea ice keeps a cap on frigid water, keeping it cold and protecting it from heating up. Losing the sea ice of the Arctic is likely to have major repercussions for the climate, he said. "There could be dramatic changes to the climate of the northern region due to the creation of a vast expanse of open water where there was once effectively land," Professor Wadhams said. "You're essentially changing land into ocean and the creation of a huge area of open ocean where there was once land will have a very big impact on other climate parameters," he said.





    http://news.independent.co.uk/world/science_technology/article312997.ece



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  2. sister_sue48

    sister_sue48 Member

    I have always been interested in global warming. I found your post very interesting.
    Thanks:icon_sunn
     
  3. Auggie2k

    Auggie2k Back to business! Established Member

    Rights lads, were all going for a swim! (J/K)

    Interesting read, nice one krell!
     
  4. Krell

    Krell worthless dirtball Expert

    And thank to YOU

    I want to keep our members posted on when and where to buy liferafts etc.

    I watched Water World again to make sure im up on all the futuristic flood technologies

    and how to handle hot flood victims with bratty kids


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  5. origin

    origin exploited of deleted.....

    nice imformative post i enjoyed it! thanks :)

    l8
     
  6. Excrement_Cranium

    Excrement_Cranium Just Sick Established Member

    Have they found any evidence of a global warming cycle?

    I know there is a theory that the hole is the ozone is actually part of the Earth's natrual cycle. And if I remember right, during the reign of giant lizards, the world was mostly tropical.

    Could we just be accelerating ourselves into a preset oblivion?
     
  7. ferrarimodena360

    ferrarimodena360 Yada Yada Yada

    thank god for wifi

    lol
     
  8. shawners

    shawners Hurt no more my son.

    with the chaos cloud comming, im sure global warming isnt the worst of our problems =)
     
  9. Auggie2k

    Auggie2k Back to business! Established Member

    Lol, good one!
     
  10. bobhss

    bobhss Cornerstone 2007

    If they know we've past the point of no return I want my CFCs back!
     
  11. mfgbypooter

    mfgbypooter Super Pooper Staff Member Moderator

    I live pretty high up I'm ready for some ocean front property.

    *
     
  12. riderx

    riderx Member

    that has been on my mind for quite a while.
    you know what upsets me man?
    the heat is terrible and i am hot blooded i am always sweating i have ac on 75 right now.
    its only going to get worse.

    there are things that can be done to help curve global warming* but it remains to be unseen
     
  13. Auggie2k

    Auggie2k Back to business! Established Member

    Yeah, the heat we had this summer (and even for Ireland) was roasting. Thing is though hot summers bring cold ass winters and I was out last night and I couldn't feel my hands - and it's only september!
     
  14. riderx

    riderx Member

    but of course auggie
    are you kidding me last year we had some nice snow storms, which i dont mind.
    i love the cold, you can do something about it, put on extra clothes etc outside, but with the heat index and going out u wear a little clothes or no clothes at all, and u burn, not excluding the fact if your sick or something or have asthma, you would be screwed.

    then u have to worry about heat stroke etc.
    with the cold you put on a coat if u want, and you are cool
    i love the cold weather i wasnt born in the summer either :)
    cheers
     
  15. RACKnRAIL

    RACKnRAIL 今は知っているでしょ Staff Member Moderator

    Mother nature has a harsh way of telling us humans to fuck off and start smelling the coffee.
     
  16. Excrement_Cranium

    Excrement_Cranium Just Sick Established Member


    Try less sweaty activity..... oh hot blooded one.
     

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