I have said it before, and I am going to say it again, global warming is not a gradual process. My theory is that it only appears gradual because we are in the first steps of an exponential growth pattern. Global warming mechanisms tend to “feed” off each other, melting sea ice means more darker water exposed so more heat is absorbed leading to more ice melting, CO released from permafrost due to global warming means more CO in the air leading to more warming, plants suck up CO when they have too much they pump out less water, less water means less water vapor to reflect sun light, less water in the air means more in the rivers and streams which leads to sea level rise, you get the idea… these are but a few of the MANY feedback loops that could throw us into a downward spiral of global warming, and now it seems there is another feedback loop starting. The Greenland ice sheet is melting faster than we thought, much faster.

The amount of ice flowing into the sea from large glaciers in southern Greenland has almost doubled in the past 10 years, possibly requiring scientists to increase estimates of how much the world’s oceans could rise under the influence of global warming, according to a study being published Friday in the journal Science.

The authors said there is evidence the rise in flows would soon spread to glaciers farther north on the vast island, whose ice sheet is nearly 2 miles thick in places and holds enough water to raise global sea levels 20 feet or more should it all flow into the ocean.

The study, which compared satellite measurements of the ice in 1996, 2000 and 2005, was performed by NASA’s Jet Propulsion Laboratory in California and the University of Kansas.

“When you have this widespread behavior of the glaciers, where they all speed up, it’s clearly a climate signal,” Eric Rignot, the study’s author, said in an interview. “The fact that this has been going on now over 10 years in southern Greenland suggests this is not a short-lived phenomenon.”

More here.

The study is the first to examine the rate of change in glaciers to establish how much ice is being lost from Greenland.

The Greenland Ice Sheet – a mass of glacial ice and snow covering 1.9 million sq km – is twice the size of France and Germany put together.

It could raise the global sea level by 7m if it melted entirely.

In the past 20 years, air temperature in southeast Greenland has risen by 3C.

Eric Rignot, of the California Institute of Technology, said Greenland could be contributing as much as 0.5mm to the global sea-level rise each year.

Details of the study were also published yesterday in the journal .

Last September, American experts warned if trends continued, the summertime Arctic Ocean could be ice-free by the end of the century.

A recent British report warned that melting ice could increase sea levels by 12m unless temperatures stabilised.

And here.

GREENLAND’S glaciers are melting into the sea twice as fast as previously believed, the result of a warming trend that renders obsolete predictions of how quickly the Earth’s oceans will rise over the next century.

The new information, from satellite imagery, gives fresh urgency to worries about the role of human activity in global warming. The Greenland data is mirrored by findings from Bolivia to the Himalayas, scientists said, noting that sea-level rise threatens widespread flooding and severe storm damage in low-lying areas worldwide.