New Orleans Faces Inevitable Submersion by Ocean Within Decades, Study Warns

Residents navigate a flooded neighborhood in Barataria, Louisiana, near New Orleans, following Hurricane Ida in August 2021. | Brandon Bell/Getty Images

New Orleans has reached a critical threshold where ongoing sea-level rise and wetland erosion will soon make it unsustainable, according to a stark new study published in Nature Sustainability. The research concludes that the city may be completely surrounded by the Gulf of Mexico before 2100, necessitating immediate relocation efforts.

Why New Orleans Is at Risk

The study highlights three primary threats to the region:

• Rising sea levels: Driven by global heating, sea levels in southern Louisiana are projected to rise by 3–7 meters.
• Wetland loss: Up to 75% of the remaining coastal wetlands could disappear, causing the shoreline to shift inland by as much as 100 km (62 miles).
• Subsidence and industrial impact: The coastline has been destabilized by oil and gas extraction, compounding the effects of climate change.

These factors make southern Louisiana the most physically vulnerable coastal zone in the world, according to the researchers. The study compares current conditions to a period 125,000 years ago when similar global temperatures led to significant sea-level rise.

Implications for the City

New Orleans, with a population of approximately 360,000, faces an uncertain future. The paper warns that without immediate action, population decline will accelerate in a disorderly manner. Researchers emphasize that while climate mitigation remains essential, the region has already passed a critical tipping point.

"While climate mitigation should remain the first step to prevent the worst outcomes, coastal Louisiana has evidently already crossed the point of no return."

Levees and Flood Defenses Are Not Enough

Billions have been invested in levees, floodgates, and pumping systems since Hurricane Katrina in 2005. However, the study warns that these defenses will eventually become inadequate due to the accelerating threats. Upgrades to existing systems will only provide temporary relief.

"In paleo-climate terms, New Orleans is gone; the question is how long it has," said Jesse Keenan, a climate adaptation expert at Tulane University and co-author of the study. He added that the timeframe for planning a retreat is likely "decades rather than centuries."

"Even if you stopped climate change today, New Orleans’s days are still numbered. It will be surrounded by the Gulf of Mexico."

Call for Immediate Action

The researchers urge policymakers to begin planning for a managed retreat from New Orleans and surrounding areas. Without proactive measures, the transition could become chaotic and unplanned, exacerbating social and economic challenges.