NASA: Sea levels are rising faster than previously thought

Sea levels are rising faster than previously anticipated—and it's only going to get worse.

According to NASA, sea levels have risen an average of three inches in the past 23 years—with some locations measuring rises as high as nine inches since 1992.

Steve Nerem of the University of Colorado, Boulder, and lead of NASA's Sea Level Change Team notes, "it's pretty certain we are locked into at least three feet of sea level rise, and probably more...but we don't know whether it will happen within a century or somewhat longer."

%shareLinks-quote="NASA attributes the accelerated pace to three major causes: melting ice sheets, melting glaciers around the world and the expansion of warming seawater." type="spreadWord"%

The accelerated pace doesn't show any signs of slowing. In fact, if ice sheets collapse, it would accelerate even more; potentially putting entire coastal cities and oceanic populations at risk.

Predictions about just how long before this could occur are difficult due to the uncharted territory of ice sheet collapse. But not impossible. One such piece of equipment relied upon by NASA in its analysis is so precise it can measure the height of a dime from 40,000 feet.

The picture, however bleak, could be a best-case scenario: some analyses show a rise in excess of ten feet over the next century is plausible.

Can't get enough from NASA? See the Hubble Telescope's best pictures below: