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.
I am begining to suffer a Ron Cobb vision of George Bush staggring through a blizzard a petrol bowser and nothing to connect it to.