thinkprogress.org - Joe Romm - June 23, 2013

Scientist: ‘Miami, As We Know It Today, Is Doomed. It’s Not A Question Of If. It’s A Question Of When.’

Jeff Goodell has a must-read piece in Rolling Stone, “Goodbye, Miami: By century’s end, rising sea levels will turn the nation’s urban fantasyland into an American Atlantis. But long before the city is completely underwater, chaos will begin.”

Goodell has talked to many of the leading experts on Miami including Harold Wanless, chair of University of Miami’s geological sciences, department, source of the headline quote. The reason climate change dooms Miami is a combination of sea level rise, the inevitability of ever more severe storms and storm surges — and its fateful, fatal geology and topology, which puts “more than $416 billion in assets at risk to storm-related flooding and sea-level rise”:

South Florida has two big problems. The first is its remarkably flat topography. Half the area that surrounds Miami is less than five feet above sea level. Its highest natural elevation, a limestone ridge that runs from Palm Beach to just south of the city, averages a scant 12 feet. With just three feet of sea-level rise, more than a third of southern Florida will vanish; at six feet, more than half will be gone; if the seas rise 12 feet, South Florida will be little more than an isolated archipelago surrounded by abandoned buildings and crumbling overpasses. And the waters won’t just come in from the east – because the region is so flat, rising seas will come in nearly as fast from the west too, through the Everglades.

Even worse, South Florida sits above a vast and porous limestone plateau. “Imagine Swiss cheese, and you’ll have a pretty good idea what the rock under southern Florida looks like,” says Glenn Landers, a senior engineer at the U.S. Army Corps of Engineers. This means water moves around easily – it seeps into yards at high tide, bubbles up on golf courses, flows through underground caverns, corrodes building foundations from below. “Conventional sea walls and barriers are not effective here,” says Robert Daoust, an ecologist at ARCADIS, a Dutch firm that specializes in engineering solutions to rising seas.

The latest research “suggests that sea level could rise more than six feet by the end of the century,” as Goodell notes, and “Wanless believes that it could continue rising a foot each decade after that.”

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