A piece of news that nobody quite knows how to process is followed by a certain kind of silence. In New Orleans, a recent paper co-authored by Tulane University’s Jesse Keenan in Nature Sustainability has created precisely that kind of quiet. Don’t panic. Really, not denial. Just the odd, suspended silence of a city being informed, in calm, scholarly terms, that it has already crossed a boundary it will never be able to cross again.
The working assumption in coastal Louisiana for many years was something like this: we have until 2050, maybe a little longer, to figure things out. The levees would continue to be raised by engineers. After each storm, the streets would continue to be drained by pumps. Even with their current state of disrepair, the wetlands would hold the line for a sufficient amount of time. It now appears to be a generous assumption. According to the study, which is based on paleoclimate data from an interglacial period approximately 125,000 years ago, southern Louisiana is facing a rise in sea level of three to seven meters and the loss of roughly three-quarters of its remaining coastal wetlands. Researchers predict that the shoreline may move up to 60 miles inland, effectively stranding both Baton Rouge and New Orleans.
When Keenan spoke to Leila Fadel of NPR earlier this month, he used a line that sticks in your memory. “In paleo-climate terms, New Orleans is gone; the question is how long it has.” That sentence has a subtle brutality to it. It doesn’t dispute. It is not hedging. It just watches.
It is difficult to overlook the contradiction when strolling through the Lower Ninth Ward on a muggy afternoon. stilted houses. Old waterlines are covered with new paint. restaurants promoting brunch. After Katrina, a city spent two decades and billions of dollars constructing a fortress of levees, floodgates, and pumps, only to be informed that the fortress would never be sufficient. Approximately 80% of the city’s land area is at or below sea level. In Keenan’s words, it is basically a bowl. The ground, which has been heavily damaged by decades of oil and gas extraction, is slowly sinking while the water surrounding the bowl rises.
Thus far, the political reaction has been muted. That is not wholly unexpected. It is not a successful campaign message to inform 360,000 people that their city is the world’s most physically vulnerable coastal zone. Nor is it suggesting—no matter how subtly—that preparations for a well-organized retreat north should start now, while there is still time to do it effectively. Some local officials believe that talking about moving would be tantamount to leaving the city. Quietly, others worry that it would be worse to not have the conversation.
The timeline might turn out to be more compassionate than the paper implies. Climate forecasts are not predictions. Sea level rise is accompanied by lag, uncertainty, and feedback loops that could have unanticipated resolutions. However, the timeline might also be more severe. Hurricanes are becoming more powerful. The loss of wetlands is already increasing. Since 2000, the coastal zone’s population has been steadily decreasing, with each significant storm pushing the curve lower. In other words, depopulation caused by climate change has already started. It is not anticipated in the paper. It’s explaining it.
The study’s cultural significance is what sticks out when you read it with the local responses. The French Quarter. The second line. The meal. the genius of improvisation that gave country jazz its name. None of that can be repeated in a drier location. People can be moved by you. A culture that developed, root and branch, in a particular swampy area is difficult to relocate.
It’s difficult to ignore how infrequently cities receive this kind of warning when observing this develop from a distance. The majority of disasters don’t leave a paper trail. There are footnotes in this one. The question of whether anyone acts on them is quite different.
