Sea levels may surge twice as fast as originally thought thanks to Antarctica

Rising sea levels are more threatening than originally believed, according to a new study on Antarctic glaciers in the journal Nature.

The study identified “previously underappreciated processes” by which glaciers melt that can contribute to rising sea levels. It found that warm ocean currents erode glaciers from beneath. As the stabilizing ice shelves on the edges of the glaciers melt, they expose sheer cliffs of ice, which then collapse into the ocean under their own weight.

These cliffs can be around 300 feet tall. The collapsing ice cliffs have “the potential to contribute more than a metre [about 3.3 feet] of sea-level rise by 2100,” the authors write. The study was led by Robert M. DeConto of the University of Massachusetts, Amherst and David Pollard of Penn State University.

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But according to Dr. Ben Strauss of the news and research organization Climate Central, the effects could be even worse.

In a conversation with NewsHour Weekend anchor Hari Sreenivasan, Strauss estimates that we could see “up to 6 feet of sea level rise by the end of the century,” taking into account the study and additional factors such as “a warming, expanding ocean and melting glaciers in Greenland.”

This amount of sea level rise would be far worse than any previous estimation. “[Six feet] used to be the extreme worst-case scenario,” says Strauss, “and now, it’s the middle of the new range.”

According to Strauss, different parts of the world would experience different levels of sea increase: “The least affected place will be Antarctica itself and the Southern Ocean, but pretty much all populated areas of the Earth will experience sea level rise.”

Areas north of the equator would be especially vulnerable, with East Asia and the East Coast of the United States being hit the hardest. In particular, Strauss singled out south Florida, Boston and New York City as potential disaster zones, projecting that “we would in New York see Hurricane Sandy-level floods every other year.”

This extreme jump in sea levels would only be the beginning of a global environmental catastrophe, according to Strauss.

“We can’t think of 6 feet as what we have to cope with. Six feet is the number in the year 2100, but after that, sea levels continue to rise at a pace exceeding one foot per decade,” he said. But Strauss is holding out hope that his dire prognostications will not come to pass.

“The silver lining here is these projections show Antarctica would be stable, if we can meet the goals of the recent Paris Agreement, if we can very aggressively reduce emissions,” he said.

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