Ice Caps Melting Fast: Say Goodbye to the Big Apple?

It is hard to shock journalists and at the same time leave them in awe of the power of nature. A group returning from a helicopter trip flying over, then landing on, the Greenland ice cap at the time of maximum ice melt last month were shaken. One shrugged and said:"It is too late already."

What they were all talking about was the moulins, not one moulin but hundreds, possibly thousands. "Moulin" is a word I had only just become familiar with. It is the name for a giant hole in a glacier through which millions of gallons of melt water cascade through to the rock below. The water has the effect of lubricating the glaciers so they move at three times the rate that they did previously.

Some of these moulins in Greenland are so big that they run on the scale of Niagra Falls. The scientists who accompanied these journalists on the trip were almost as alarmed. That is pretty significant because they are world experts on ice and Greenland in particular. We were visiting Ilulissat, Greenland, once a stronghold of Innuit hunters but now with so little ice that the dog sleds are in danger of falling through even in the depth of winter. But it is not the lack of sea ice that worries scientists and should be of serious concern to the inhabitants of coastal zones across the world. Cities like New York and states like Florida are in the front line.

Scientists know this already, but just to give you some idea of the problem, the Greenland ice cap is melting at such a fast rate it is triggering earthquakes as pieces of ice several cubic kilometres in size break up.

Scientists say the acceleration of melting and subsequent speeding up of giant glaciers could be catastrophic in terms of sea level rise and make previous predictions published this year by the Intergovernmental Panel on Climate Change (IPCC) far too low. The glacier at Ilulissat, which it is believed spawned the iceberg which sank the Titantic, is now flowing three times faster into the sea than it was 10 years ago.

Robert Correll, chairman of the Artic Climate Impact Assessment, from Washington told me:"We have seen a massive acceleration of the speed with which these glaciers are moving into the sea. The ice is moving at 2 metres an hour on a front five kilometres long and 1,500 metres deep. "That means that this one glacier puts enough fresh water into the sea in one day to provide drinking water for a city the size New York or London for a year."

Professor Correll, who is also director of the global change programme at the Heinz Centre in Washington said the estimates of sea level rise in the IPCC report in February had been "conservative" and based on data two years old. The range of rise this century had been predicted to be 20 to 60 centimetres, but would be the upper end of this range at a minimum and some now believed it could be two metres. This would have catastrophic effects for European and US coastlines.

He said newly invented ice penetrating radar showed that the melt water was pouring through to the bottom of the glacier creating a melt water lake 500 metres deep causing the glacier "to float on land. "These melt water rivers are lubricating the glacier, like applying oil to a surface and causing it to slide into the sea. It is causing a massive acceleration which could be catastrophic."

The glacier is now moving at 15 kilometres a year into the sea although in periodic surges it moves even faster. He has seen a surge, which he had measured as moving five kilometres in 90 minutes - an extraordinary event.

If all of Greenland melts, something we were previously assured would take thousands of years, but now could be hundreds, then sea level round the world would rise seven metres. That is without any contribution from the Antarctic, the glaciers of Alaska, the Rockies, the Himalayas, or the ocean water expanding as it warms.