Susan Solomon, a senior scientist at the National Oceanic and Atmospheric Administration in the US, told the International Herald Tribune that the Gulf Stream and North Atlantic Current seem to be more stable - and less susceptible to global warming - than previously thought: 'We now believe we are much farther from that threshold, thanks to improved modelling and ocean measurements,' she said.
The opinion was backed up by the latest report from the Intergovernmental Panel on Climate Change, which drew on the data from 23 different climate models to conclude that it is 'very unlikely' that the northwards flow of warm water in the Atlantic would stall this century, although it is still expected to weaken.
'The bottom line is that the atmosphere is warming up so much that a slowdown of the North Atlantic Current will never be able to cool Europe,' Helge Drange, a professor at the Nansen Environmental and Remote Sensing Center in Bergen, Norway, told the paper.
Scientists believe that for the warm water current to stop, the entire Greenland ice sheet would have to melt fast enough to create a huge freshwater 'pool' in the North Atlantic. This dilution would interrupt the currents of salt water which flow up from the South, then sink as the salt-water becomes cooler and hence more dense.
Some environmentalists remain to be convinced that European cooling is not a threat. In his latest book, Six Degrees, climate change campaigner Mark Lynas writes that 'another decade's worth of information will need to be collected and analysed to be sure'.
This article first appeared in the Ecologist May 2007
