Coastal communities, including those in Newfoundland and Labrador, could be drowned by significant sea level rise before the end of the century according to a new report released by the U.S. government.

Boris Worm, a marine scientist at Dalhousie University in Halifax, N.S., says a report by the American National Oceanic and Atmospheric Administration suggests sea levels could rise by 2.5 metres by the year 2100.

"They were asking the question, how will any given amount of sea level rise be felt in the U.S. and what are the likely scenarios for sea level rise given current emissions," he told CBC Radio's The Broadcast.

It really means a complete rethinking of how we live close to the coast. - Boris Worm

"They've come up with a range of projections, and the notable thing here is that that range of projections is a lot larger than it used to be."

Worm said less than a decade ago, the expectation was between one and two feet of sea level rise by the end of the century.

"They've now corrected this and said it's going to be a lot more, and it could be up to 8.2 feet," he said.

"If that comes true, it means New York turns into some kind of modern Venice, Venice turns to some kind of Atlantis, and I don't know what it means for Newfoundland … it really means a complete rethinking of how we live close to the coast."

'Threat to human life'

Worm said this kind of sea level rise could be devastating for coastal communities and that significant investment is needed to protect these areas.

"It could mean that a lot of coastal properties that are built close to the water would be at risk, a lot of the infrastructure — roads often hug the coastline," he said.

"What we have to add on top of that is the rising risk of floods, severe floods, those that destroy property and are a threat to human life."

Even one foot of sea level rise could increase the risk of severe flooding by up to 25 times, according to the report.

Higher than average rise in N.L.

Worm said water levels will rise between one to eight feet around the world on average, however eastern Canada including Newfoundland is expected to see a higher than average rise.

'These ice shelves are collapsing from the inside out.' - Boris Worm

The change in expected sea rise is connected to new evidence related to the instability of the Greenland and Antarctic ice shelves, which were previously thought to be stable.

"What we've been learning very recently is that these ice shelves are collapsing from the inside out. That means that the ocean is hollowing them out from underneath, the ocean that is warming," he said.

"The smoking gun that we've been looking for — lots of melt water, billions of cubic metres of melt water, in fact — hasn't been there, and so we were tricked into believing that nothing was happening, while all this time the ocean was eating away at these ice shelves."