Britain faces big chill as ocean current slows

Discussion in 'Your Bloody Soap Box' started by Wurm, May 16, 2005.

  1. Wurm

    Wurm New Member

    Joined:
    Aug 6, 2004
    Messages:
    2,203
    Likes Received:
    0
    Jonathan Leake, Science Editor
    The Times Online (UK)
    May 08, 2005
    http://www.timesonline.co.uk/article/0,,2087-1602579,00.html


    CLIMATE change researchers have detected the first signs of a slowdown in the Gulf Stream - the mighty ocean current that keeps Britain and Europe from freezing.

    They have found that one of the "engines" driving the Gulf Stream - the sinking of supercooled water in the Greenland Sea - has weakened to less than a quarter of its former strength.

    The weakening, apparently caused by global warming, could herald big changes in the current over the next few years or decades. Paradoxically, it could lead to Britain and northwestern and Europe undergoing a sharp drop in temperatures.

    Such a change has long been predicted by scientists but the new research is among the first to show clear experimental evidence of the phenomenon.

    Peter Wadhams, professor of ocean physics at Cambridge University, hitched rides under the Arctic ice cap in Royal Navy submarines and used ships to take measurements across the Greenland Sea.

    "Until recently we would find giant 'chimneys' in the sea where columns of cold, dense water were sinking from the surface to the seabed 3,000 metres below, but now they have almost disappeared," he said.

    "As the water sank it was replaced by warm water flowing in from the south, which kept the circulation going. If that mechanism is slowing, it will mean less heat reaching Europe."

    Such a change could have a severe impact on Britain, which lies on the same latitude as Siberia and ought to be much colder. The Gulf Stream transports 27,000 times more heat to British shores than all the nation's power supplies could provide, warming Britain by 5-8C.

    Wadhams and his colleagues believe, however, that just such changes could be well under way. They predict that the slowing of the Gulf Stream is likely to be accompanied by other effects, such as the complete summer melting of the Arctic ice cap by as early as 2020 and almost certainly by 2080. This would spell disaster for Arctic wildlife such as the polar bear, which could face extinction.

    Wadhams's submarine journeys took him under the North Polar ice cap, using sonar to survey the ice from underneath. He has measured how the ice has become 46% thinner over the past 20 years. The results from these surveys prompted him to focus on a feature called the Odden ice shelf, which should grow out into the Greenland Sea every winter and recede in summer.

    The growth of this shelf should trigger the annual formation of the sinking water columns. As sea water freezes to form the shelf, the ice crystals expel their salt into the surrounding water, making it heavier than the water below.

    However, the Odden ice shelf has stopped forming. It last appeared in full in 1997. "In the past we could see nine to 12 giant columns forming under the shelf each year. In our latest cruise, we found only two and they were so weak that the sinking water could not reach the seabed," said Wadhams, who disclosed the findings at a meeting of the European Geosciences Union in Vienna.

    The exact effect of such changes is hard to predict because currents and weather systems take years to respond and because there are two other areas around the north Atlantic where water sinks, helping to maintain circulation. Less is known about how climate change is affecting these.

    However, Wadhams suggests the effect could be dramatic. "One of the frightening things in the film The Day After Tomorrow showed how the circulation in the Atlantic Ocean is upset because the sinking of cold water in the north Atlantic suddenly stops," he said.

    "The sinking is stopping, albeit much more slowly than in the film - over years rather than a few days. If it continues, the effect will be to cool the climate of northern Europe."

    One possibility is that Europe will freeze; another is that the slowing of the Gulf Stream may keep Europe cool as global warming heats the rest of the world - but with more extremes of weather.


    -------------------

    This is pretty scary stuff, and apparently is no longer mere "speculation". But in Bush's myopic fantasy world, none of this is happening...


    Gee, we wouldn't want Big Industry to have to spend any of their enormous profits to clean up their act, would we? And who needs fuel-efficient cars when we can "fill 'er up" every 5 miles in our gas-hogs??
     
    Tags:


  2. limerickman

    limerickman Moderator

    Joined:
    Jan 5, 2004
    Messages:
    16,130
    Likes Received:
    115
    This phenomena has been apparent for the past 10 years or so.
    Britain and Ireland's climate is totally dependent on the Gulf stream - which ensures mild winters and relatively mild summers.

    Studies conducted in this country show that water temperatures are dropping in winter and increasing in summer.
    The effect of this can be seen on plantlife on the south coast of Ireland.
    Flora that grows in warmer climates, could previously be cross fertilised in locations along the south coast.
    In the past 10 years, the success of this cross fertilisation has dramatically decreased because temperatures are dropping.
     
  3. MountainPro

    MountainPro New Member

    Joined:
    Aug 11, 2004
    Messages:
    3,071
    Likes Received:
    1
    near where i live we have some plants and trees that, according to scientist, are from the gulf of Mexico. They are growing right on our beaches and are a direct result of the gulf stream. The seed pods float in the current and as soon as they hit land the start to grow.

    the instances of these plants arriving here are reducing however...
     
  4. limerickman

    limerickman Moderator

    Joined:
    Jan 5, 2004
    Messages:
    16,130
    Likes Received:
    115
    Yeah, my old next door neighbour (not O'Connor who nearly burned down me cottage) was a botanist.
    I remember him telling that plants from West Indies were cross fertilised and managed to grow in the Burren (in County Clare on the Irish west coast).
    Until recently these plants prospered.
    This is no longer the case because the temperature has dropped marginally year on year since 1989.
     
  5. Wurm

    Wurm New Member

    Joined:
    Aug 6, 2004
    Messages:
    2,203
    Likes Received:
    0
    I think you guys in the Isles ought to start practicing your CXing skills more, coz that's what your road cycling may start to look like if this cooling continues.

    :confused:
     
Loading...
Loading...