New Orleans has reached a “point of no return” and relocation of its residents should begin immediately, as the city could be surrounded by the Gulf of Mexico before the end of this century due to the climate crisis, a new study has concluded. The paper, published in the journal Nature Sustainability, warns that ongoing sea-level rise and rampant wetland erosion in southern Louisiana will swallow the area within a few generations.
The study, which compared current global temperatures with a period of similar heat 125,000 years ago, estimates that southern Louisiana faces 3-7 metres of sea-level rise and the loss of three-quarters of its remaining coastal wetlands. This would cause the shoreline to migrate as much as 100km (62 miles) inland, effectively stranding New Orleans and Baton Rouge. The region is described as the “most physically vulnerable coastal zone in the world”.
Jesse Keenan, a climate adaptation expert at Tulane University and co-author of the paper, said: “In paleo-climate terms, New Orleans is gone; the question is how long it has.” He added that the timeframe for planning a retreat is “most likely decades rather than centuries”. Even if climate change were halted today, the city’s days are numbered, as it sits in a bowl-shaped basin below sea level and cannot be kept afloat indefinitely.
Billions of dollars have been spent on levees, floodgates and pumps since Hurricane Katrina in 2005, but the study warns these defences will not save the city in the long run. Keenan called for coordinated efforts to help people move away, starting with the most vulnerable communities, such as those in Plaquemines parish outside the levee system. “New Orleans is in a terminal condition, and we need to be clear with the patient that it is terminal,” he said.
The study notes that Louisiana has already experienced population loss, and this trend will accelerate in a disordered way without action. A separate study released last week found that 99% of New Orleans’ population faces major risk of severe flooding, the highest exposure of any US city. Co-author Wanyun Shao, a geographer at the University of Alabama, described the situation as “a timebomb” and agreed that relocation is inevitable.
