JAKOBSHAVN GLACIER, Greenland (AFP) - The chaotic cavalcade of blueish ice tumbling into the sea from the world's fastest-moving glacier is sounding a daily climate change alarm, say scientists ahead of International Polar Day on Friday.
The Jakobshavn Glacier, on Greenland's west coast, is melting twice as fast as 10 years ago and advancing toward the sea at 12 kilometres (seven miles) per year, compared with six kilometres (three and a half miles) before.
In its 4th Assessment report issued earlier this year, the UN's Intergovernmental Panel on Climate Change (IPCC) said the world's oceans could rise by 50 centimeters (20 inches), putting tens of millions, perhaps hundreds of millions of people at risk by century's end.
But that estimate does not factor in the latest findings about the melting of glaciers in Greenland and loss of ice in Antarctica, which many experts say could eventually increase sea levels, and the rate at which they rise, by several fold.
Jakobshavn, moving toward the ocean at a clip of 30 to 40 metres a day, is but a single icy tongue reaching out from the Greenland icesheet, a massive block of ice and snow up to three kilometres (1.9 miles) thick covering 80 percent of the island, which is four times the size of France.
If the sheet's entire 2.85 million cubic kilometres (685,000 cubic miles) of ice were to melt, it would lift sea levels by seven metres (23 feet), swamping every major coastal city in the world.