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What's left of Antarctica's Larsen B Ice Shelf, at least 10,000 years old and 27 times the size of Manhattan, is weakening quickly and likely to disintegrate within five years, according to a new NASA study.
NASA's Ala Khazendar, who led the study at the agency's Jet Propulsion Laboratory in Pasadena, California, said, while it's fascinating to have a front-row seat to the dramatic transformation, it's really bad news for the planet.
"Our study shows that the remaining parts will be gone soon, in the blink of an eye," Khazendar told VICE News. "A lot of these changes that we are witnessing in the polar regions, amongst others, are probably already set in motion. There is no turning back."
Ice shelves are permanent floating sheets of ice that are connected to landmasses around the world, and more than 99 percent of the freshwater ice on Earth is contained in ice sheets in the Antarctic and Greenland. While the shelves disintegrating and shattering into icebergs won't increase the sea level directly, they act as a barrier between the massive glaciers that lie behind them and the ocean. And in absence of the shelves, the glaciers flow more quickly into the ocean, leading to sea level rise. Scientists say the world's oceans are rise, on average, an estimated 3 millimeters per year — and accelerating.
"It is really startling that an ice shelf we know that has existed for 10,000 years has disappeared so quickly. We should keep this image in mind," Khazendar told VICE News. "If it hasn't happened yet, this should be a wake-up call for us to act in order to try lessen the impact of our activities on the climate."
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Located on the eastern side of the Antarctic Peninsula, which has warmed 2.5 degrees Celsius (4.5 degrees Fahrenheit) in the past 50 years — one of the fastest warming regions anywhere on Earth. Larsen B was the site of what Khazender called "the defining moment in our field." In 2002, two-thirds of the shelf collapsed, seven years after another large piece, Larsen A, disintegrated.
And sobering news emerged this week about Larson B's mammoth neighbor, Larsen C. About ten times the size of B, just a bit smaller than West Virginia, scientists had long debated whether Larsen C was thinning due to warmer air or warmer ocean currents.
A study published by the British Antarctic Survey (BAS) found that both, in fact, are to blame. When it comes to the fast-warming Antarctic, lead author of the BAS study Paul Holland told VICE News: "Nowadays, it's more remarkable to find something that hasn't changed."
"The changes we see are surprising when we first see them, and then we scientists become used to them," he said. "It is now commonplace in the scientific literature that glaciers are accelerating, thinning, retreating, and collapsing."
In total, the glaciers in the Antarctic Peninsula — including those held back by Larsen B and C — could contribute about half a meter (1.5 feet) of global sea level rise, according to the US Geological Survey. And, while nobody is predicting the entire Antarctic ice sheet will melt, it contains enough ice to raise the seas by a staggering 60 meters (200 feet) if it did.
"I think it is possible that Larsen C Ice Shelf could collapse within the lifetime of my children, perhaps well within it, but perhaps not at all," Holland told VICE News. "That is a very shocking prospect indeed."
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The International Panel on Climate Change warns that seas could rise by up to 1 meter (3 feet) by 2100, putting flagship world cities, like Shanghai, New York, Mumbai, and London, at serious risk without major adaptation.
And that much rise is enough to put the world's lowest-lying places in jeopardy. Twenty million Bangladeshis could be forced off their land with a meter of rise, and countries like the Marshall Islands, which sit 2 meters (7 feet) above sea level, and Kiribati, home to 100,000 people, could be swallowed entirely into the sea.
Last year, hedging their bets against a future forced climate migration, the Kiribati government bought land 1,200 miles away in Fiji. Also last year, a Kiribati man sought to become the world's first "climate change refugee," arguing that global warming was gradually destroying his homeland and his family would face "serious harm" if they returned. He lost his bid for asylum in New Zealand.
"Some of the island nations feel they're facing an existential threat to their own survival. They almost feel desperate about what's taking place," Khazendar told VICE News. "It will be very destructive, and that's why we and so many research groups are putting a lot of effort to try to quantify by how much the sea level will rise and how quickly."
Follow Darren Ankrom on Twitter: @darrenankrom