In 25 years, West Antarctica tripled its rate of ice loss

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Satellite surveys showed that, prior to 2012, Antarctica lost ice at a steady annual rate of 76 billion tons and contributed 0.2 millimeters per year to sea level rise.

Louisa Casson, of Greenpeace UK's Protect the Antarctic campaign, said: "Governments can take a historic step forward in October this year if they decide to create an Antarctic Ocean Sanctuary, protecting 1.8 million square kilometres in what would be the largest protected area on Earth".

The next 10 years will be critical for the future of Antarctica, and choices made will have long-lasting consequences, says an global group of award-winning Antarctic research scientists in a paper released Thursoday. Over thousands of years the layers of snow build up and compact, forming a sheet of ice up to thousands of metres thick and thousands of kilometres across.

Writing in Nature, the authors are all winners of the Tinker-Muse Prize for Science and Policy in Antarctica and experts in such disciplines as biology, oceanography, glaciology, geophysics, climate science and policy.

Each of these plays an important environmental role: the ice sheet holds enormous freshwater reserves, the ice shelves feed freshwater into the ocean, and the sea ice is more reflective of sunlight than the water it floats in, which reduces the amount of heat the planet absorbs. As the continent rose, the ice sheet began to self-stabilize.

"If you start removing mass from there, you can have a very large scale evacuation of ice into the ocean and significant sea level rise", she continued. "Under natural conditions, we don't expect the ice sheet to lose ice at all", continues Shepherd, "There are no other plausible signals to be driving this other than climate change". The Antarctic Peninsula is also seeing ice melt. "This information could have an impact on our projected timelines for ice shelf collapse and resulting sea level rise due to climate change". Globally sea levels are rising by about 3mm a year.

"There are about 150 different estimates of ice loss from Antarctica and Greenland and they use different methods, they cover different proportions of the ice sheets and they cover different time periods", Shepherd said.

"If you're close to the ice sheet that's losing mass you don't really feel the effects as much".

Hamish Pritchard summer clouds swirl around the Staccato Peaks of Alexander Island off the Antarctic Peninsula. In a study released Wednesday
In 25 years, West Antarctica tripled its rate of ice loss

Antarctica is the largest ice sheet on Earth and nearly 220 billion tonnes of it is melting into the ocean each year.

As lead author Andrew Shepherd of the University of Leeds in the United Kingdom told the New York Times, this six-inch rise in the world's sea levels would translate into a dramatic increase of floods in the Brooklyn borough of New York City.

Because of all the melted ice, the global sea level has risen by 7.6 millimetres.

Antarctica is covered by ice sheets that get channelled into the oceans through a network of ice streams and glaciers and the continent has seen a reduction in the extent of floating ice shelves. None." The Times explains: "Dale said that global carbon emissions from energy had risen by 1.6% last year, after three years of "little or no growth".

Antarctica's glaciers carry ice from the interior of the continent to the ocean.

"If we aren't already alert to the dangers posed by climate change, this should be an enormous wake-up call", he added.

Or alternatively, he continued, Antarctica could drive faster changes, ones that "begin to exceed what we're going to be able to cope with".

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