New research is showing that rising sea levels will sink Miami in the not-so-distant future.

The catastrophe is happening, according to a blog in the Miami New Times. The question is when South Florida will sink.

The answer, according to new work by a University of Miami researcher: even more quickly than we thought.

“People ask me all the time: ‘When is it going to happen? When will we start seeing sea level rise?’” Brian McNoldy, a senior research associate at the university’s Rosenstiel School of Marine and Atmospheric Sciences, told the paper. “We’ve already passed that. It’s happening.”

To chart that rise, McNoldy recently crunched nearly two decades’ worth of data from a tidal monitoring station on Virginia Key. First he looked at the heights of high, low and mean sea level measured at the station from 1996, when it was set up, until today.

In research that was posted in February, he reported that in 2014 the linear trend in all three was more than three inches higher than in 1996.

Even more worrying, though, the data suggest that the trend is accelerating. By charting just the highest tide each day and breaking that info into five-year chunks, McNoldy found that the high-water mark rose by an average of 0.3 inches a year overall — but a much higher 1.27 inches a year during the last five years.

“It was surprising,” McNoldy says. “I didn’t realize that over such a short time, going back to only 1996, you’d see that much of a trend.”

One challenge in convincing people to take the threat of rising seas seriously is that the change is incremental; it’s not a sudden Pompeiian eruption, but a slow-motion disaster.

But McNoldy says he hopes his data add more fuel to the growing conversation about what to do in Miami, where the risks include not only billions of dollars’ worth of property along the coastline, but also a fresh-water table — the drinking water source for millions — that could soon be infiltrated by rising seawater.

McNoldy does not have any answers, but he’s glad we’re talking about them.

“That’s one good thing about Miami,” he says. “Here people do recognize what’s happening and they are trying to do things, while other parts of our country are turning their backs.”

Cover photo courtesy of Bill Cooke via the Miami New Times. This post originally appeared here.