The Ilulissat glacier in Greenland, a UN heritage site considered one of the wonders of the world, has shrunk by over 10 kilometers in just a few years, in one of the most alarming examples of global warming in the Arctic region.

"We are witnesses to one of the most striking examples of climate change in the Arctic," US expert Robert Corell said during a recent helicopter flight over the glacier.

The lower extremity of the glacier "has receded by more than 10 kilometers (six miles) in two or three years after having been relatively stable since the 1960s," he said.

Corell was in charge of the Arctic Climate Impact Assessment, a 1,400-page report written by more than 250 scientists and published in November 2004 which sounded alarm bells for the region.

The report warned that less than a century from now, the Arctic ice could melt completely during the summer, threatening many species and the lifestyle of the indigenous Inuit population.

Corell, a senior fellow with the American Meteorological Society in Washington D.C., took 22 environment ministers and other officials from around the world, meeting in Ilulissat last week for a conference on global warming, on a tour of the glacier to see the effects first-hand.

"We can't find any more concrete example of Arctic warming, which is twice as fast as in any other part of the world," Corell told AFP.

He said the glacier shrank by seven kilometers (4.3 miles) in a 12-month period from 2002 to 2003.

"The glacier front is calving (scientific term meaning to release) huge ice rocks and moving 35 meters (yards) per day or around 13 kilometers (eight miles) a year, and discharging icebergs in the sea," he said.

"When a glacier recedes, it means that it is diminishing, which is an obvious sign of global warming," Corell said.

The drastic effects of climate change on the glacier have also been studied by Jason Box, a professor with the Byrd Polar Research Center at Ohio State University in the United States.

He recently led a research project on the glacier financed by US space agency NASA, with logistical support from environmental group Greenpeace.

His team used a small inflatable boat outfitted with special equipment to measure the depth of the ice cap's lakes, and found that water production had increased by 30 percent in just 17 years.

"We've observed an increase in the melt rates in recent years, consistent with warming observed at coastal weather stations," he said in a Greenpeace video report from the area.

The environmental group sent its vessel Arctic Sunrise to Greenland for two months this summer to raise awareness about global warming, with the final days of the campaign taking place in the Ilulissat fjord.

"More water is moving through the Greenland ice sheet system and there appears to be a link between more abundant melt water and the observed increase in ice flow acceleration," Box said.

The volume of water in the inland ice is important because it affects the speed with which the icebergs travel to the sea, and thereby affects the water level of the world's oceans.

"It's not a tomorrow issue, but a today issue," Corell told the 22 ministers.

"There is no time to lose. Urgent action must be taken to respond to this problem," Martina Krueger, the head of the Greenpeace expedition to Greenland told AFP.

If global warming continues the way experts fear it will, Greenland's ice cap could melt within a few hundred years, raising the water level of the world's oceans by six to seven meters (20 to 23 feet).

That would threaten the lives of the more than 1.2 billion people who live within 30 kilometers (20 miles) of ocean shorelines.