News Column

Florida Is Ground Zero for Global Warming

May 8, 2014

Wendy Koch, USA TODAY

Miami skyline (file photo)
Miami skyline (file photo)

Miami and other parts of South Florida, where streets routinely flood at lunar high tides, comprise one of the most vulnerable hot spots for climate change.

"It's remarkable. We get calls from people asking: 'It didn't rain, so why is my street underwater?'" says Broward County Commissioner Kristin Jacobs, noting the region's decades-old system to drain water is now causing it to bubble back up.

"I have a photo of a man swimming -- doing the backstroke -- in his cul de sac," she says, adding that 30% of her county -- just north of Miami -- is 5 feet or fewer above sea level.

Jacobs attended the White House's release Tuesday of the National Climate Assessment, a massive study by scientists that finds rising temperatures are already affecting the United States. It notes Miami -- along with New Orleans, Tampa, Virginia Beach and Charleston, S.C. -- is most at risk for sea-level rise.

As Earth's temperature warms, so do the seas, because warmer water takes up more room than cooler water. Globally, sea level has risen about 8inches since reliable record-keeping began in 1880 and is most likely to rise another 1 to 4 feet by 2100, the report says.

That's bad news for the highly developed coasts of Florida's southern tip, where land is flat, low-lying and swampy.

"The underlying rock is limestone, which allows groundwater to seep in," says Leonard Berry, director of Florida Atlantic University's Center for Environmental Studies, noting he's seen even swanky cars like Lamborghinis flooded. He says the porous bedrock makes it difficult to build a sea wall that will keep out saltwater intrusion, because such a barrier would have to go down at least 60 feet.

"Trillions of dollars of investments ... are going to be vulnerable," Berry says, especially since the region is prone to hurricanes that can bring storm surges made worse by sea-level rise.

The region also has a disproportionate share of elderly residents, many ironically drawn to Florida for its balmy weather, says Vicki Arroyo, executive director of the Washington, D.C.-based Georgetown Climate Center. She says the elderly, more susceptible in heat waves and less apt to relocate in storms, were hardest hit when Hurricane Katrina hit New Orleans in 2005.

Even a sea-level rise of 6 inches will be costly in South Florida. "That will happen in the next two to three decades," says Ben Strauss of Climate Central, a Princeton-based non-profit group that used federal data for its Surging Seas database. The region's most likely rise in sea level will range between 5 and 13 inches by 2040, according to federal projections.

So by mid-century, Strauss says there's at least a 78% chance of severe flooding of at least 2 feet above the high-tide line.

Sea levels are rising more quickly in other places, notably Virginia's Norfolk area, but Strauss says South Florida is vulnerable because of its topography, population and infrastructure.

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Original headline: Global warming's ground zero



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