The ice breaker L'Astrolabe is seen in the Antarctic sea in this undated handout photo.

ON BOARD L'ASTROLABE, Southern Ocean: As Captain Benoit Hebert steers the icebreaker l'Astrolabe on Monday through a stormy Southern Ocean heading for Antarctica his thoughts will soon turn to the dangers of icebergs.

Large icebergs have recently been spotted floating hundreds of kilometres (miles) north of Antarctica -- a sign of the accelerating melt of East Antarctica due to climate change.

But Hebert's thoughts will also be on a gathering on the other side of the earth in Copenhagen, where he hopes world leaders will agree to dramatically cut greenhouse gas emissions blamed for global warming.

Hebert has been sailing the icy seas around Antarctica and the Arctic for more than 15 years and has seen first hand the effects of global warming.

"Climate change is a lot more visible in the north in the Arctic rather than in the Antarctic. The Arctic is made up of pack ice which is melting.," he said.

Total summer ice cover in the Arctic Ocean was only about half the level it was in 1950, according to the International Panel on Climate Change.

The Arctic is warming at about three times the global rate and global warming will leave the Arctic Ocean ice-free during the summer within 20 years, says one British polar scientist.

Climate Optimists

East Antarctica has been losing ice at an average rate of 5 to 109 gigatonnes a year from April 2002 to January 2009, but the rate accelerated from 2006, says University of Texas scientists.

Fifteen years ago Hebert sailed the Southern Ocean to Antarctica and has been back on the sea route from Australia to the French base of Dumont D'Urville for the past two years.

While scientists document an increase in Antarctic melt, Herbet is optimistic the southern ice continent will survive.

"I haven't noticed any increase in melting ice during my time sailing this route," he said. "All the scientists know that the pack ice in the Arctic will disappear very soon."

"Whereas Antarctica is fresh water ice, it's a very large continent. I don't think Antarctica is a threat."

Alexandre Trouvilliez, an engineer in environmental hydrology, is travelling to Antarctica to measure and quantify blowing and drifting snow to estimate surface ice mass.

Trouvilliez is optimistic that Copenhagen will see the world act to stop global warming as it includes many nations not party to the Kyoto Protocol, like the United States and China.

"I think one of the biggest advances will be the emergent countries like China joining and making great advances," he said. "I hope the outcome will be the reduction of the number of C02 and methane gases."

Benoit Vanniere, a volunteer PHD student travelling to Antarctica to measure the temperature, is also optimistic.