A stark new study has concluded that New Orleans has reached a 'point of no return' due to ongoing sea-level rise and rampant erosion of wetlands in southern Louisiana, which will see the city surrounded by the Gulf of Mexico within decades. The paper, published in the journal Nature Sustainability, estimates that the New Orleans area 'may well be surrounded by the Gulf of Mexico before the end of this century' as the climate crisis accelerates.
Multiple Threats Facing Southern Louisiana
Low-lying southern Louisiana faces multiple threats, including rising sea levels driven by global heating, strengthening hurricanes, and the gradual subsidence of a coastline carved apart by the oil and gas industry. The study compares today's rising global temperatures with a period of similar heat 125,000 years ago, which caused a rise in sea level of 3-7 metres. This scenario would lead to the loss of three-quarters of the region's remaining coastal wetlands, causing the shoreline to migrate as much as 100km (62 miles) inland, thereby stranding New Orleans and Baton Rouge.
Immediate Action Required
The researchers state that this makes the region the 'most physically vulnerable coastal zone in the world' and requires immediate action to prepare a smooth transition for people away from New Orleans, which has a population of about 360,000. Louisiana has already experienced population loss in recent years, and this trend will accelerate in a disordered way should no action be taken, the paper warns.
'While climate mitigation should remain the first step to prevent the worst outcomes, coastal Louisiana has evidently already crossed the point of no return,' the perspectives paper adds. Billions of dollars have been spent to fortify New Orleans with a vast network of levees, floodgates, and pumps erected after 2005's catastrophic Hurricane Katrina. However, the growing threats mean the levees will not be able to save the city in the long run.
Expert Views
Jesse Keenan, an expert in climate adaptation at Tulane University and a 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.' Keenan stressed that even if climate change stopped today, New Orleans's days are still numbered because it will be surrounded by open water and cannot be kept afloat below sea level.
Keenan urged city, state, and federal leaders to begin work to help support people moving away from the New Orleans region in a coordinated way, starting with the most vulnerable communities such as those in Plaquemines parish who live 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. 'There is an opportunity for palliative care, we can transition people and the economy. We can get ahead of this.'
Challenges and Political Will
New Orleans faces obvious challenges as it sits in a bowl-shaped basin below sea level, with 99% of its population at major risk of severe flooding, the worst exposure of any US city according to a separate study released last week. Wanyun Shao, a co-author of that study and a geographer at the University of Alabama, said: 'Even compared to all other US cities, New Orleans really stands out, which is alarming. There is no specific timeline to how long New Orleans has left but we know it's in big trouble. They are facing one of the highest sea level rises in the world and I don't know how long human effort can fight against that tide. It's like a timebomb.'
Shao agreed that relocation of people would have to take place, despite it being a politically and emotionally charged issue. 'Managed retreat, no matter how unappealing it may be, is the ultimate solution at some point,' she said.
Land Loss and Mitigation Efforts
Since the 1930s, Louisiana has lost 2,000 sq miles of land to coastal erosion, equivalent to the size of Delaware, with a further 3,000 sq miles set to vanish over the next 50 years. The rate of land loss is so rapid that a football pitch-sized area is wiped out every 100 minutes. To help counter this, Louisiana last decade settled upon a plan to harness the Mississippi River's natural ability to rebuild land, known as the Mid-Barataria Sediment Diversion project, which broke ground in 2023. However, Louisiana's Republican governor, Jeff Landry, scrapped the project last year, arguing its $3bn cost was too high and that it threatened the state's fishing industry.
Proponents of the project, funded via a settlement from BP over the Deepwater Horizon disaster, decried the decision as disastrous for the state. Garret Graves, a Republican former congressman who once led the state's coastal restoration agency, called it a 'boneheaded decision' that would result in one of the largest setbacks for the coast and community protection in decades. According to the new research paper, the loss of the sediment diversion plan 'effectively means giving up on extensive portions of coastal Louisiana, including the New Orleans area.'
Legal and Future Outlook
A legal effort to force oil and gas companies to pay for damage to Louisiana's coastline is also in doubt. This month, the US Supreme Court allowed the fossil fuel industry to federally contest a state jury decision that Chevron pay $740m to remedy harm caused to wetlands. Keenan said the combination of these decisions is driving a scenario where the state has stopped trying to build land, accelerating the timeline for New Orleans's demise.
While the US has never wholesale moved a major city before, numerous communities have relocated for economic reasons in the past, with some now being shifted due to the climate crisis. Keenan suggested that the government could start planning and building appropriate infrastructure in safer areas on the other side of Lake Pontchartrain, north of New Orleans. 'This could be an opportunity for New Orleans to help migrate people further north, invest in long-term infrastructure and make that sustainable,' he said. 'That exodus has already begun, so if nothing is done, people will just trickle out over time and it will be an uncoordinated mess. The market will speak as people won't be able to get insurance. Louisiana has to stop the bleeding and acknowledge this is happening. But at the moment there is no plan.'
Timothy Dixon, an expert in coastal environments at the University of South Florida who was not involved in the new paper, said the study highlights the challenge Louisiana faces with subsiding land combined with rising sea levels. 'New Orleans is not going to disappear in 10 years or anything like that, but policymakers really should've thought about a relocation plan a century ago,' he said. 'Governments may not have the ability to just command people to leave, but people will volunteer to move and we are seeing that already. I'm not optimistic our political system is capable of dealing with this stuff, it will take leadership and unpopular decisions. Also, many people don't want to move. They love where they are born.'
Landry's office was contacted for comment but did not respond.
