Wetlands Quagmire "Talking about the town of New Orleans itself is kind of tricky," says shorelines researcher Rob Young of Western Carolina University. "If we wanted to spend a lot of money, we could defend the city for some time. It's one of America's cultural draws." On the other hand, he gives smaller communities in the area a life expectancy of about 10 years. Nor will tearing down levees to restore wetlands help, Young said, adding that the popular belief that wetlands protect communities against storm surges is all wet. "So many environmental groups -- even those I am a member of -- bought into this idea that wetlands restoration will solve this," said Young. "In my opinion there's simply no evidence that the level of wetland protection would make any difference for storm protection." The problem is that the storm surge models used for that argument suffer from gaping unknowns, the biggest being that actual storm surges are notoriously hard to measure, says Young. The most accurate method is to go into an area after a storm and measure high-water lines and debris left in high places. But there are no high places in wetlands to get that data, so it's a guessing game at best. "No one has ever measured a storm surge over a wetland," said Young. "I'm all for wetland restoration. I think there is a lot of value in wetlands. But it's not going to save these communities in the Bayou." "The only thing that will stop a storm surge is a coastal forest, and there are no coastal forests here," added Dokka. Planning for the Inevitable People communicating these hazards to coastal residents can't always take such a hard line, however. "We wouldn't go into New Orleans, which is still trying to recover from the effects of Katrina, and say 'get out'," said Sandra Eslinger of the National Oceanic and Atmospheric Administration. "That's not an option." Instead, she says she tries to encourage rebuilding infrastructure with an eye toward what the area is going to look like in the next 50 or 100 years. In the short term, that means rebuilding the levees so they hold back water successfully. It also means raising houses as an added level of protection, should the levees fail. As New Orleans continues to sink and sea level continues to rise, residents have to weigh the resilience of the levees and floodgates against their ability to retain ties to friends and family, church, and everything that defines their identity. "Just because the physical infrastructure is at risk, you can't just tell people to move to another location and it's that simple, because it's not," Eslinger says. "Sense of place is truly important." Eslinger is trying to incorporate long-term forecasts in sea level rise into local community planning, but says it's very difficult. "The longest term people think about is buying a home, maybe a 30-year time horizon. A 50 to 100-year time horizon is a different way of thinking," she said, though during that time global sea levels could rise half a meter, imperiling millions living in coastal communities. "In the long term the answer is that some of the communities are going to be abandoned," concludes Young. And New Orleans? "That's a political question, not a scientific one," he says. "At the end of the day, those of us who are scientists just have to look at the science." Related Links: Discovery News blog: Strike Slip Discovery News blog: Earth Impacts Treehugger.com: Interview with Chris Mooney, author of "Storm World" |
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