New Orleans may be surrounded by the Gulf of Mexico before the end of this century, according to a May 2025 analysis in Nature Sustainability. The city sits below sea level in a shrinking delta, making it especially exposed to sea level rise projected at 10 to 23 feet for coastal Louisiana.

75% of remaining wetlands could vanish and shoreline retreat may reach 62 miles inland. Louisiana has already lost 2,000 square miles of wetlands since the 1930s, stripped by development, oil and gas canals, and river levees that starved them of sediment.

About 99% of New Orleans residents face high flood risk. The city lost 25% of its population after Hurricane Katrina, with departures spiking after each major storm. Experts warn that waiting for a crisis risks a chaotic retreat that deepens inequality for the poorest residents. Gov. Jeff Landry cancelled a 2025 sediment diversion project meant to protect the region.