An increasing number of studies are starting to shape the apocalyptic image of global warming and its negative effects. Last week, Rutgers researchers announced that global ocean levels are rising twice as fast today as they were 150 years ago, and that the culprit was global warming. Another study, this time carried out by the Bern University warned that carbon dioxide and methane levels were 27% higher and 130% respectively than they have been in the last 650,000 years.

It's a well known-fact that, because of the increase in greenhouse gases, the circulation of the oceans is disturbed and the latest study carried out by the National Oceanography Centre in Southampton comes with an additional proof to that.

According to the researchers, the powerful ocean current which transports warm water to Britain and northern Europe has weakened dramatically in recent years because of the global warming. As a result, the inhabitants of these regions are likely to experience harsher winters and cooler summers.

The scientists estimate that the energy involved in the circulation process is equivalent to that produced by 1 million power plants. Harry Bryden, the author of the study, warns that the volume of water brought by the current which drives the Gulf Stream has decreased by 6 million tones of water per second.

Alarmed by this discovery, the researchers have devised a 4.8 million pound monitoring network which should provide an answer to the question: "Is the weakening of the current of short-term variation or is it part of a devastating long-term process?"

"Models show that if it shuts down completely, 20 years later, the temperature is 4C to 6C degrees cooler over the UK and north-western Europe," Dr Bryden said.

According to Guardian Unlimited, the current works as a conveyor belt which circulates the heat from the equatorial regions to the Arctic Circle. Warm surface water coming up from the tropics gives off heat as it moves north until, eventually, it cools so much in northern waters that it sinks and circulates back to the south.