The oceans are rising faster than at any point in the last 28 centuries, and human emissions of greenhouse gases are primarily responsible, scientists reported Monday.

They added that the flooding that is starting to make life miserable in many coastal towns — like Miami Beach; Norfolk, Va.; and Charleston, S.C. — was largely a consequence of those emissions, and that it is likely to grow worse in coming years.

The scientists confirmed previous estimates, but with a larger data set, that if global emissions continue at a high rate over the next few decades, the ocean could rise as much as three or four feet by 2100, as ocean water expands and the great ice sheets in Greenland and Antarctica begin to collapse.

I think we can definitely be confident that sea-level rise is going to continue to accelerate if there’s further warming, which inevitably there will be.

Experts say the situation will grow far worse in the 22nd century and beyond, likely requiring the abandonment of many of the world’s coastal cities.

“I think we can definitely be confident that sea-level rise is going to continue to accelerate if there’s further warming, which inevitably there will be,” said Stefan Rahmstorf, a professor of ocean physics at the Potsdam Institute for Climate Impact Research in Germany and co-author of a paper released Monday by the Proceedings of the National Academy of Sciences.