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New York City Is Weighing Ambitious Plans for Flood Defenses

Rising sea levels are threatening the city’s existence, but several bold plans could prevent the next catastrophe.

New York City faces a conundrum. Its low-lying land is at ever-increasing risk of flooding as climate change contributes to sea level rise, but many of those areas are also home to incredibly expensive real estate. In the short term, if it wishes to retain its position as a global center of business rather than simply relocating its residents, it needs to protect its inhabitants from the aquatic attack brought about by global warming.

In 2012, Superstorm Sandy brought a surge of water upon the city that was up to nine feet taller than a typical high tide. But a recent study in Nature estimated that by 2100, Antarctic thawing alone could raise sea levels by three feet, which suggests that extreme weather events could cause even more damage in the future.

There are many possible solutions. Some, such as the Blue Dunes concept, are audacious. That proposal suggests building a 40-mile chain of islands from New Jersey to Long Island to dissipate the huge quantities of energy within freak waves and reduce the impact of the next Sandy. Others—such as entirely redesigning streets and overhauling subterranean transport and utilities infrastructure—are likely too complex to enact.

The most compelling idea right now, it seems, has been proposed by Bjarke Ingels Group, a Danish architectural firm. That shouldn’t, perhaps, be surprising—the Europeans do, after all, know a thing or two about living with seas that are higher than land. BIG’s proposal is to build a gigantic berm around lower Manhattan, which could one day reach from 42nd Street in the east to 57th Street on the west. If, that is, the potential $3 billion required to build it can be scraped together.

Nicknamed “Big U,” the—let’s be honest—wall would in theory be designed to provide locals with more than just flood protection. Think landscaping, bike paths, and other modern urban design tricks which are used to make ugly things attractive. Critics suggest that budget constraints may stymie some of those ambitions, though, leaving Manhattan with, well, just a wall.

There are other criticisms—the most obvious being that the Big U would serve to protect Wall Street at the expense of other parts of New York, such as Brooklyn and Queens, which were hammered during Sandy. Then there’s the fact that it’s been designed to defend against a one-in-100-year flood with 30 inches of contingency built in for sea-level rise. That’s is unlikely to be enough protection in the long-term.

New York, then, faces difficult decisions over how to protect itself from rising waters and freak weather events. None of the solutions are cheap, nor without their faults. But at least one of them will have to be chosen if the city is to survive.

(Read more: Rolling Stone, Nature, “Life Below Sea Level in the New Age of Climate-Change Engineering”)

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