Coastal cities in the U.S. - New Orleans, Boston, and Miami chiefly among them - are facing an increasing likelihood of being engulfed in rising sea levels brought on by climate change.

According to Agence France Press, a new study published in the journal Proceedings of the National Academy of Sciences suggested the sea level rise for some of these cities is irreversible. Regardless, it advocates for immediate action in cutting carbon emissions and implementing clean energy systems to start making a difference.

"Some of this could happen as early as next century," study lead author Ben Strauss, vice president for sea level and climate impacts at Climate Central, told AFP. "But it might also take many centuries.

"Just think of a pile of ice in a warm room. You know it is going to melt, but it is harder to say how quickly."

Cities like New Orleans and Miami may not be able to avoid sea levels eventually rising to claim significant portions of land.

"Some cities appear to be already lost," Strauss told CBS News. "For New Orleans, there are levees, it's possible to build levees higher and stronger for some time, but that's not necessarily safe or sustainable in the long run. We've already seen what can happen when levees break, when the sea level gets higher, the bigger the tragedy can be.

"We have a lot of resources, a lot of money compared to most places at risk, I think we have an opportunity to invest, to find an economic opportunity and reduce the pain of loss," he said. "We can pioneer those kinds of measures that could become an expertise we could export to the world. It could be a service."