Sea Level Is Accelerating

Satellite data confirm what computer models have warned for years: Oceans are rising faster as the planet warms, and coastal communities face increasing flood risk.

Rising sea levels increase the risk of storm surge flooding in coastal cities like Charleston, South Carolina, shown here after Hurricane Matthew. Credit: Brian Blanco/Getty Images

Even cities that already know they're at risk may not be able to prepare fast enough without additional investments in disaster relief and resilience. That includes Tampa, where his university is based. The city has been listed as one of the 10 cities globally most vulnerable to sea level rise. If the rates of adaptation and mitigation don't keep pace, damage from storm surges and extreme rains is likely to increase.

Some scientists also warn that a rapid disintegration of Antarctica's ice sheets could push sea level up much faster and higher, by as much as 4 to 10 feet by 2100. 

The last time Earth was as warm as it is now was about 125,000 years ago, and we know sea level was 6 meters higher than it is today, Nerem said. "The big question is, now long will it take to get there."

Combined with analyses of long-running sea level data from coastal tide gauges and related research on ice sheet stability, scientists can now create a surprisingly detailed picture of how sea level rise will affect coastal communities, even down to the neighborhood level, as shown in these NOAA maps.

As Steve Nerem, Associate Director of the Colorado Center for Astrodynamics Research at the University of Colorado Boulder and one of the study’s authors, told ThinkProgress, the study’s conclusions are based on the assumption that “the ice sheets [will] just continue going along at what they’ve been doing for the last 25 years.”

Basically, he said, the study “has a major caveat that [it assumes that] sea level continues to change into the future at the same rate and acceleration of change as the last 25 years. Like I said, that’s probably not going to happen, [our findings are] probably on the low end.”


The researchers, however, are very confident that sea levels will continue to rise at an accelerated rate.

This expected increase is compared to just 7 cm – or 2.7 inches – of the global average sea level rise experienced since 1993. As the study notes, one of the main causes behind the accelerating sea level rise is the melting of ice sheets in Greenland and Antarctica – and this is one of the biggest variables that will impact how quickly the seas will continue to rise.

Because of this, the researchers say their findings are a “conservative” estimate. If the climate starts to change even more rapidly, then the rate of sea level rise could increase even more.