The transatlantic current which brings mild weather to Western Europe has slowed down by 30%, according to the UK's National Oceanography Centre, raising fears of rapid climate change "within a decade".

The Gulf Stream current is 30% weaker today than half a century ago, scientists from the UK's National Oceanography Centre have discovered after taking measurements across the Atlantic.

The team of scientists warn that the slowing down could mean a rapid cooling for the UK and the rest of Western Europe, "not in a matter of days […], but probably within a decade." If the current were to stop, they say, cold Canadian style winters would become the norm in Western Europe.

The measurements were taken across the Atlantic from Morocco to Florida between spring 2004 and spring 2005. They included temperature, salinity, currents and pressure and were taken at various depths about every 50 kilometres. Similar measurements have already been taken along the same latitude in the past, in 1957, 1981, 1992 and 1998, said Harry Bryden of the National Oceanography Centre. But this is the first time that they are showing signs of a decline in the current's circulation, he said.

However, scientific journal Nature quotes other scientists as saying the available data only gives a snapshot of the situation. They point out that natural fluctuations should be considered too. Instruments have been installed that will monitor the current's circulation at all depths. They should give us a clearer picture in about four years, Nature says.