Scientists Say Slower Atlantic Currents Could Mean a Colder Europe - New York Times

By ANDREW C. REVKIN Published: December 1, 2005 Scientists say they have measured a significant slowing in the Atlantic currents that carry warm water toward Northern Europe. If the trend persists, they say, the weather there could cool considerably in coming decades. Some climate experts have said the potential cooling of Europe was paradoxically consistent with global warming caused by the accumulation of heat-trapping 'greenhouse' emissions. But several experts said it was premature to conclude that the new measurements, to be described today in the journal Nature, meant that such a change was already under way.The currents, branching off from the Gulf Stream, are part of an oceanic system that disperses tropical heat toward the poles and makes Northern Europe far warmer than its latitude would suggest.Warming, in theory, could stall the salty, sun-heated, north-flowing currents by causing fresh water to build up in high-latitude seas as ice melts and more precipitation falls.The scientists, from the National Oceanography Center in Britain, measured sea temperature, currents and other conditions across the Atlantic from the Bahamas to Africa last year and found a 30 percent drop in the flow of warming waters since a similar set of measurements were taken in 1957. The team, led by Harry L. Bryden, wrote that even though they had measurements from only 5 years out of the past 50, the pattern of change seen at various depths supported the idea that the shift was a significant trend and not random variability."