One of the world's largest glaciers, on the west coast of Greenland, is shrinking at an alarming rate as a result of global warming - with potentially dire consequences.

Ilulissat, a Unesco-listed glacier, is shedding ice into the sea faster than ever before, according to one of Denmark's top experts on glaciology. Andreas Peter Ahlstroem, a researcher with the Geological Survey of Denmark and Greenland institute, said that the glacier has receded by more than 15 kilometres since 2001.

"Its calving rate (breaking off of ice) has never been so rapid," he said.

The Ilulissat glacier and icefjord have been on Unesco's world heritage list since 2004 and is the most visited site in Greenland, its ice and pools of emerald-blue water admired by tourists and studied by scientists and politicians around the world.

The Danish government chose Ilulissat as the venue for recent talks with some 30 countries to discuss ways to slow global warming - a place that Shfaqat Abbas Khan, a glacier expert from the Danish Space Centre, describes as the "most visible and striking example of climate change."

The glacier is the most active in the northern hemisphere, producing 85 million tonnes of icebergs per day, according to Dr Khan.

He has been studying Ilulissat using satellites, GPS or through his own visits to the area and says December's UN climate change conference in the Danish capital of Copenhagen may come too late to save the glacier.

"A lot of glaciers in Greenland are melting at more or less the same pace and even with an ambitious agreement at the summit ... it will be impossible to stop this," Dr Khan said.

The melting ice is both a consequence and a cause of global warming: ice reflects heat, as opposed to water which absorbs it and warms up the climate, thus causing more glaciers and snow to melt.