But scientists are still unable to make predictions precise enough for people to plan how to handle the loss of land and threat to coastal communities expected over this century, two researchers point out in a commentary this week in the May 4 issue of the journal Science.

 

"We know sea level is going to rise, but how much, and how fast, and where, we really still don't know," co-author Josh Willis, a climate scientist at NASA's Jet Propulsion Laboratory, told LiveScience. 

 

It turns out the ocean isn't like water in a bathtub; it doesn't rise uniformly as more water pours in. As global warming raises sea levels, some places are expected to see higher-than-average increases, and a few places may even see decreases.

Currently, projections suggest that over the course of this century, sea levels will rise between 8 inches and 6.6 feet (20 centimeters and 2 meters) around the planet. Scientists know this increase will be driven by the expansion of water as it warms (warmer water takes up more space) and the melting of ice, most importantly, ice stored in the massive ice sheets that cover Greenland and Antarctica.