If drastic cuts aren’t made in greenhouse gas emissions, the watery New York landscape that followed Hurricane Sandy could be the new normal in less than a century—and that same soggy future goes for Boston, Miami, Norfolk, and hundreds of other U.S. cities and towns. For some, the destiny is already certain.

“Even if we could just stop global emissions tomorrow on a dime, Fort Lauderdale, Miami Gardens, Hoboken, New Jersey will be under sea level,” Climate Central researcher Benjamin Strauss told the Guardian.

Strauss outlined his projections in a report published in the Proceedings of the National Academy of Sciences late last month. He used another recent PNAS study to determine when cities would be “locked-in” to future higher tide lines that could threaten a given percentage of the population. The base study, authored by Anders Levermann and other scientists, found that average global sea levels will eventually rise 4.2 feet for every one-degree Fahrenheit jump in temperature.

That means, at today’s emission rates, 25 percent of the current populations of more than 1,700 cities and towns would live under a future high-tide level rise by 2100, according to the Guardian. Even changing that amount to 50 percent only drops the number of cities threatened to 1,400 (an interactive map on the Climate Central website allows users to dial the ominousness up or down based on factors such as pollution, lock-in year, and population percentage threatened).

“Hundreds of American cities are already locked into watery futures and we are growing that group very rapidly,” Strauss told the Guardian. “We are locking in hundreds more as we continue to emit carbon into the atmosphere.”

If the cities are to be saved, Strauss writes in a Climate Central article, it will take “a halt to global emissions growth by 2020, followed by rapid global emissions reductions, and a massive program to remove carbon from the atmosphere, resulting in net negative emissions — atmospheric clean-up — by late in the century.”

Far from net negative emissions, the American Meteorological Society’s annual State of the Climate report, released Tuesday, indicates global CO2 emissions were at an all-time high in 2012. Other greenhouse gases were also on the rise, according to the report.

For some, the inclination might be to view Strauss’s projections as far away and likely to be addressed in the long run. But for many coastal communities, the encroaching ocean is an ever-present problem.

From deteriorating beaches in New York to disappearing wetlands in Louisiana, climate change—along with poor land stewardship—has come home to roost. Communities are facing more frequent and extreme storms, and have fewer natural bulwarks to protect them.

By some estimates, at least half the coastal properties between Maine and Texas have lost significant amounts of marshlands and barrier islands. Louisiana, for instance has thought to have lost nearly 2,000 square miles in the past 80 years.

“Louisiana is in many ways, one of the best examples of starting to see some of the near-term implications of climate change,” environmental policy expert Jordan Fischbach, told USA Today. "In some ways, I feel like it is the canary in the coal mine because they are seeing effects that change people's day-to-day lives."

If that’s true, then the view from Louisiana State Highway 1, should be a good indicator of what the future of Strauss’s report might look like.

"All the open water you are seeing was once wetlands," Hilary Collis of the Coalition to Restore Coastal Louisiana, told USA Today. "Just a few millimeters at a time it sank, and now it's gone."