ROBERT SIEGEL, host:
From NPR News, this is ALL THINGS CONSIDERED. I'm Robert Siegel.
MICHELE NORRIS, host:
And I'm Michele Norris.
We continue our series on national parks with a visit to one of the most vulnerable national treasures in the U.S. - Everglades National Park. Most of the park, at the southern tip of Florida, is just a few feet above sea level and that's a big problem when it comes to global warming.
As NPR's Greg Allen reports, park officials say there's only one way to counter rising sea levels and that's to restore the Everglades to the way it used to be.
GREG ALLEN: It's a big job, in fact the largest environmental restoration project ever undertaken and may end up costing close to $20 billion. And what do you get for all that money?
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ALLEN: Bob Johnson is just the person to show you.
Mr. BOB JOHNSON (Director, South Florida Natural Resources Center): We're right on the edge of the Marl Prairies that form the eastern edge of Shark Slough, which is the main flow way of the park.
ALLEN: Johnson is the director of the South Florida Natural Resources Center, the person who oversees the health of the Everglades for the National Park Service. We're on an observation platform that overlooks the heart of the Everglades, thousands of acres of fresh water wetlands, mostly saw grass with scattered trees on either side of a wide, slow-flowing channel - Shark River Slough.
Mr. JOHNSON: Think about this as a flood plain. Shark River Slough is the central river. And those areas historically stayed wet not only all year, but for long durations of time - 10, 15, 20, 30 years at a time, it would stay continuously wet.
ALLEN: But that was then, most years now the saw grass prairies in the Everglades dry out. That's led the changes in vegetation and the animals that use the area, fewer wading birds like woodstorks and roseate spoonbills, for example. But Johnson says the big casualty in the Everglades, the key part of the ecosystem that's hurt most by the increasing dry periods, is something that decidedly less glamorous - the thick layer of decomposing vegetation: peat.
As the peat is lost, the ground subsides making it more vulnerable to seawater incursion. Compounding the problem - Florida is in the middle of an extended drought, which brings other threats to the ecosystem.
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Unidentified Woman: …watching and waiting. A fire (unintelligible) on half of homes as a massive brushfire burns in the Everglades.
Unidentified Man: And the smoke from the…
ALLEN: Fire is a natural part of 1.2-million-acre Everglades ecosystem, but increasing dryness has allowed fires in some areas to burn down into the peat, blazes that become difficult to put out and which cause lasting damage. Most of these problems can be traced back to flood control projects, completed in the 1950s and '60s, the protected developed areas in South Florida which channeled precious water away from the Everglades. The multibillion-dollar restoration plan aims to undo much of that damage.
But in recent years, park managers and environmental groups have become concerned about another threat to the park - global warming. In the Everglades, Bob Johnson says big chunks of habitat have already been lost because of sea level rise, including much of Cape Sable, formerly home to what's now one of the nation's most endangered species: the Cape Sable seaside sparrow. Since the 1930s, Johnson says, the sea level has climbed in the Everglades by 9 inches.
Mr. JOHNSON: That's enough to move the sea level to a point where it's actually progressing faster than the peat can be deposited and the vegetation communities can keep with it. And so you see just the change - we have this large mangrove zone, instead of the mangrove zone slowly migrating inland; it's basically disappearing and being replaced by open water areas.
ALLEN: To hold off the incursion of seawater, Johnson says there's really only one possible response - to restore freshwater flows in the park.
Sarah Fain, with the National Parks Conservation Association, says the best solution is to recreate a continuous flow channel from Everglades Park north to Lake Okeechobee, 70 miles away.
Ms. SARAH FAIN (Manager, Everglades Restoration Program): You have to be providing that water into the park in order to restore the ecosystem, to build back up the peat that helps increase the elevation of the Everglades. So I think one of the keys is to what we call decompartmentalize the Everglades, we need to take away those barriers.
ALLEN: That effort got a big boost last month when the state of Florida made a deal to buy 300 square miles of land from U.S. Sugar, one of the biggest landowners north of the park. But even if the restoration effort is successfully completed, Everglades researcher Bob Johnson says change is inevitable. The park will continue losing coastal areas and fresh water marshland. And if predictions of sea level rise prove true, in another century, large sections of the Everglades will be inundated.
Which raises a question: Why spend billions of dollars to save an ecosystem that ultimately may be doomed anyway? Johnson says because the Everglades is more than just a wilderness area, it's a safety buffer for six million people who live in South Florida.
Mr. JOHNSON: Not only is it the water supply area, not does it help control flooding in South Florida, but raising water levels in the Everglades is going to postpone, you know, set back impacts of sea level rise on water supply and flood control in developed areas. And so, we're kind of all in this together in terms of the benefits of restoring the Everglades.
ALLEN: Compared with parks that have geysers, mountains or breathtaking canyons, Johnson concedes, the Everglades is a low-key place. It was the first national park created not because of its natural beauty, but to preserve an endangered wilderness area. But the future of the Everglades, he says, is something that's important not just to some alligators and birds, but also to the health of the entire region.
Greg Allen, NPR News, Miami.
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