Dr Simon Boxall of the National Oceanography Survey said that while the planet as a whole will get much warmer the UK will see temperatures plunge as the ocean currents and weather patterns around the world change.
At the moment north west Europe particularly Britain is warmer than it should be because of the effect of the North Atlantic Drift bringing warm water from the Tropics.
This then warms sea breezes which keep temperatures mild on land.
But the process that causes this movement could be “switched off” by global warming if the Arctic heats up too much.
It will mean colder harsher winters similar to last month will become the norm and summers will become cooler and wetter.
Researchers believe that the melting of glacial ice could be contributing to the ocean becoming less saline or “freshening” and warmer – potentially leading to changes in the circulation of the seas.
Currently cold water in the high Arctic sinks into the deep sea like a plug hole pulling warmer water up from the Gulf Stream and giving north-west Europe its mild weather.
But increased levels of fresh water and warming Arctic seas could reduce the pull of the current and unbalance weather patterns around the world.
The scientists were speaking ahead of an expedition to the Arctic ice cap as part of efforts to establish how it is melting – which will help them predict if the ocean currents will change.
Explorers with the Catlin Arctic Survey expedition will venture out on to the ice to drill holes down into the ocean measuring temperature salinity and flow of the fresh water just below the sea ice.
Dr Boxall who is based at Southampton University and devised the expedition said the changes in conditions in the Arctic were “not just about polar bears and their habitats it’s about the habitats in Britain and worldwide”.
“As the ice melts you not only get loss of habitat you get changes to the current” he said.
Dr Boxall said that the North Atlantic Drift could turn off now or in 50 years but when it stops it will be sudden – take about three years – and change the UK climate to one like north west Canada and Alaska.
He said: “The extension of the Gulf Stream that affects the climate around the world could weaken or change.”
Referring to a disaster movie depicting a world thrown into a deep freeze he said: “It’s not as catastrophic The Day After Tomorrow-type scenario but UK winters would become slightly cooler and summers would be slightly wetter and cooler.
“It’s not catastrophic – we’re not going to see the English Channel freezing over. But we are more likely to be skiing in Yorkshire than sitting under palm trees.”