PORTLAND – Glaciers and ice sheets in the polar regions appear to be melting at a faster rate than anticipated, threatening a rise in sea level and heightened risk of flooding along the Maine coast, recent research indicates.

Previous forecasts said oceans would rise by up to 2 feet by the next century, but new findings now suggest that the earlier predictions may be too conservative.

Some experts, including Gordon Hamilton of the University of Maine’s Climate Change Institute, are concerned about a possible 3 feet rise within this century, which would be more than enough to flood parts of the coast and cause extensive storm damage.

“What feels like a big storm, and the property damage associated with it, will be coming more often,” said Stephen Dickson, state marine geologist at the Maine Geological Survey. “There will be a lot more vulnerable coastal property.”

Dixon and others are mapping coastal sections to try to determine which areas would be most vulnerable. Beach development rules, he said, may have to be changed to reflect the higher danger in the worst-case scenario.

One town that could be affected is Old Orchard Beach, where homes, condos, hotels, shops and an amusement park sit within a few feet of maximum sea level.

Wes Hurst, who lives in Old Orchard, has been following the reports of rising seas but isn’t overly concerned.

“I figure this place has been here over 100 years,” said Hurst, expressing confidence that the higher waters won’t be a problem for another two or three generations.

Dickson said property owners typically don’t think about what might happen 100 years in the future.

“People are more worried about next year’s nor’easters,” he said. “But the reason it’s important is that future nor’easters might be coming in at a higher level.”

Warmer waters and glacial melting has caused a nearly one foot rise in sea levels off Portland over the last 100 years, a change that has contributed to storm-related erosion at Higgins Beach in Scarborough and damage to beachfront homes at Camp Ellis in Saco.

Researchers now say that greenhouse gases accumulating in the atmosphere have accelerated the rate of melting near the north and south poles.

“There’ve been at least seven papers in the last three months that show, in one aspect or another, the change is happening faster than predicted,” Dickson said.

Hamilton visited Greenland last summer to document the migration and melting of large glaciers and was shocked at the changes from just two years before.

“Everybody’s sitting up and taking notice because nobody knew these things could happen this fast,” Hamilton said.

The implications are huge, he said, because the melting of the ice in Greenland alone would raise sea levels by more than 20 feet.

“Whole nations will just disappear in the next couple of decades if nothing changes,” he warned.

While nearly all of Maine would feel the impact in some way if sea levels rose 3 feet, he said, “the geography of the coast and the geography of wealth in Maine kind of collide south of Portland, and that’s the area most susceptible.”