A new study published in the journal Science indicates it’s now too late to stop the rise of the seas, which will increase by 20 feet and swallow much of our coastline in the coming decades.

Andrea Dutton, the lead author of the study and a geochemist at the University of Florida, said that the sea levels will rise by at least 20 feet and possibly more, and that’s only if global warming is held to just an increase of 2 degrees Celsius, the stated goal of governments worldwide that many already say is too optimistic of a goal, according to a Salon.com report.

The beginning of ice sheets melting now appears irreversible, and there is evidence that in past instances of the Earth’s history where the temperatures increase by 1 to 3 degrees Celsius, there was a similar rise in sea levels, the paper claims.

Dutton said that as the planets warm, the poles were warm at an even faster rate and could raise significant concerns about the ice sheets in Greenland and Antarctica. It will take many years for this sea level rise to happen, there is not much that can be done to stop it at this point, she said.

If such sea level rise does happen, it would completely change the American coastline.

The most recent case where sea levels rose this much was 125,000 years ago, scientists believe, when levels were 20 to 30 feet higher than the present and the global average temperature was about one degree Celsius higher. There was another warm period about 400,000 years ago when there was about a one to two degree Celsius warming, resulting in sea levels at 20 to 40 feet above today’s.