More Than 400 U.S. Cities May Be ‘Past The Point Of No Return’ With Sea Level Threats

Millions of Americans live in places where it’s too late to slow the threat of rising sea levels, a new study warns, and researchers are hoping those findings will serve as a call to action for cities that can still be saved by cutting carbon emissions.

The study, published Monday in the journal Proceedings of the National Academy of Sciences, examines how much rising sea levels will affect cities across the United States over time if carbon emissions stay the same or decrease. The most startling finding is that 414 towns and cities have already passed their lock-in date, or the point at which it’s guaranteed that more than half the city’s populated land will eventually be underwater no matter how much humans decrease carbon emissions; it’s just a matter of when.

That’s “the date where we let the genie out of the bottle, when it’s past the point of no return,” lead study author Benjamin Strauss of Climate Central told The Huffington Post.

Of those 414 cities, New Orleans stands to be one of the most compromised.

“Even in a best-case carbon emissions scenario, 98 percent of populated land in New Orleans would be below the future sea level,” Strauss said, because it’s so flat and low-lying. “So it’s really just a question of building suitable defenses or eventually abandoning the city.”

Those defenses could include higher levees around the city, but that’s not an ideal solution, Strauss said.

“How deep a bowl do you want to live in?” he asked. “We already saw with [Hurricane] Katrina what can happen when a levee is breached, and the higher the water gets and the taller the levee gets, the more catastrophic a levee breach would become.”

Conditions in New Orleans could be even worse than the study predicts, he noted, as it —> Read More