The big melt: Antarctica's retreating ice may re-shape Earth

From the ground in this extreme northern part of Antarctica, spectacularly white and blinding ice seems to extend forever. What can't be seen is the battle raging underfoot to re-shape Earth.
Water is eating away at the Antarctic ice, melting it where it hits the oceans. As the ice sheets slowly thaw, water pours into the sea 118 billion metric tons per year for the past decade, according to NASA satellite calculations.
That's the weight of more than 356,000 Empire State Buildings, enough ice melt to fill more than 1.3 million Olympic swimming pools. And the melting is accelerating.
In the worst case scenario, Antarctica's melt could push sea levels up 3 meters worldwide in a century or two, recurving heavily populated coastlines.

Parts of Antarctica are melting so rapidly it has become "ground zero of global climate change without a doubt," said Harvard geophysicist Jerry Mitrovica.
Here on the Antarctic peninsula, where the continent is warming the fastest because the land sticks out in the warmer ocean, nearly 45 billion metric tons are lost each year, according to NASA.

The water warms from below, causing the ice to retreat on to land, and then the warmer air takes over. Temperatures rose 3 degrees Celsius in the last half century, much faster than Earth's average, said Ricardo Jana, a glaciologist for the Chilean Antarctic Institute.

As chinstrap penguins waddled behind him, Peter Convey of the British Antarctic Survey reflected on changes he could see on Robert Island, a small-scale example and perhaps early warning signal of what's happening to the peninsula and rest of the continent as a whole.
"I was last here 10 years ago," Convey said during a rare sunny day on the island, with temperatures just above freezing.
"And if you compare what I saw back then to now, the basic difference due to warming is that the permanent patches of snow and ice are smaller. They're still there behind me, but they're smaller than they were."

Robert Island hits all the senses: the stomach-turning smell of penguins; soft moss that invites the rare visitor to lie down, as if on a water bed; brown mud, akin to stepping in gooey chocolate. Patches of the moss, which alternates from fluorescent green to rust red, have grown large enough to be football fields.
Though 97 per cent of the Antarctic Peninsula is still covered with ice, entire valleys are now free of it, ice is thinner elsewhere and glaciers have retreated, Convey said.