Sea levels, as we know, are incredibly sensitive to rises in global temperatures. A study released earlier this month revealed that the increase of a mere degree celsius could lead global sea levels to rise by as much as two meters. But according to a new study published in the Proceedings of the National Academy of Sciences, the implications are especially grim for the US. At the current rate of carbon emissions, over 1,700 cities, including New York, Boston and Miami, will be “locked in” by greenhouse gas emissions by this century’s end. While the study doesn’t specify when these cities would begin to fall under water, the “locked in” date marks a point at which cities would not be able to escape being submerged by water in the future. In other words, by 2100, scores of US cities will have sealed their fate.
Even more striking: Nearly 80 cities and more than 800,000 people will have sealed their fate by 2023. Cambridge, Massachusetts, which houses both Harvard University and the Massachusetts Institute of Technology, will have done so by 2060. As will Norfolk, Virginia, home to America’s largest navy base.
Unfortunately, bigger cuts to carbon emissions by the US and other big polluters may not help. “Even if we could just stop global emissions tomorrow on a dime, Fort Lauderdale, Miami Gardens, Hoboken, New Jersey will be under sea level,” author of the paper Benjamin Strauss told the Guardian. Already, half of U.S. shorelines are vulnerable to sea level rises.
Still, curbing carbon emissions could save as many as 1,000 cities from partial submergence, the study found. Even without dramatic cuts, incremental steps to lower emissions will likely spare hundreds of cities from that fate, including mega-centers like New York.
This article originally appeared on Quartz.