Scientists will brave extreme conditions to investigate the rising acidity of the Arctic Ocean in one of the first expeditions of its kind, it was announced yesterday.

The Catlin Arctic Survey 2010, starting next month, will explore the effects of increasing carbon dioxide emissions as experts warn the issue could have devastating impacts on marine life.

A team of leading international research scientists will face minus 45 C temperatures, with a wind chill factor of minus 75 C, during the two-month trip.

They will also battle against the threat of frost bite, thin ice and polar bears.

Carol Turley, of the Plymouth Marine Laboratory, said the expedition, between winter and spring, was thought to be one of the first of its kind.

"This will be one of the first chances for scientists to investigate ocean acidification under natural field conditions under the Arctic sea ice," she said.

Based on current carbon dioxide emissions, scientists predict 10% per cent of the Arctic surface could be corrosive by 2018 and 50 per cent by 2050 - levels not seen on earth for millions of years.

And it is thought the entire Arctic surface could be corrosive by the end of the century. Polar explorer Pen Hadow, director of the mission, said: "It's my view that never has there been a greater need for exploration if we are to understand how the natural world works.

"Hardly anyone goes to the Arctic Ocean - they don't see it, they don't experience it and, inevitably, the understanding is low on a global basis of what the Arctic Ocean is."

Jean-Pierre Gattuso, of the Universite Pierre et Marie Curie, said more carbon dioxide is absorbed into cold water than warmer seas, making the Arctic Ocean particularly vulnerable.

"Ocean acidification is the 'other carbon dioxide problem'," he said.

"It is certain that it will impact marine ecosystems, although we do not fully understand how all marine species will cope."

The survey will include a 310-mile trek across floating sea ice as researchers take samples from the sea and ice.

Mr Hadow said a better analysis of oceans, which absorb about a quarter of man-made carbon dioxide, was vital to understand the effects of climate change as experts predict the Arctic Ocean will be ice-free during summers within 20 years.

"We know that disappearing ice cover and potential impacts of acidity are parts of some big ocean changes," said Mr Hadow.

"Since it is widely viewed as a bellwether for wider global change, it is important we understand better what is happening."

Rising acid levels in sea water reduces the availability of the carbonate mineral - used by many marine organisms to form their shells.

This could result in a slower growth of shells and might impact on species including lobsters, crabs, mussels, oysters and sea urchins.

Six scientists will be among the group of 12 travelling to an "ice base" - about 750 miles from the North Geographic Pole.

Helen Findlay, of Plymouth Marine Laboratory, will be among those taking part in the expedition - starting on March 11 and running to the end of April.

"This is a really exciting opportunity for me as a field scientist," she said.

"It is an area of the Arctic that has not been well studied before."

The team will consume more than 6,000 calories a day - around the equivalent of six traditional cooked English breakfasts.

But they expected to lose between five and 10 kilograms in weight by the time they return.

Results of the research, due to be compiled around the end of the year, will be made available to scientists in Europe, Canada and the US.