That number could go higher depending on the amount of ice melt and the quantity of greenhouse gas emissions.
The United Nations estimates a five feet sea-level rise would be enough to swamp 17 million people in low-lying Bangladesh alone.
The new study factors in the loading and unloading of ice from North America during the ice ages preceding the long-ago sea-level rise.
As the ice sheets grew, their weight pushed down the land beneath them while causing land at the edges--Bermuda and the Bahamas--to bulge upward, says Raymo.
When the ice pulled back, the continent rebounded, and the islands sank.
"We're re-thinking many of our estimates of past sea-level rise now that we're more aware of the effects of unloading of ice," said Bil Haq, program director in the National Science Foundation's (NSF) Division of Ocean Sciences, which funded the research. "We now have a meaningful way of calculating the rebound.
"This study is a good example of collaboration between paleoceanography and geophysics to resolve an important issue: the question of future sea-level rise."
Today, both Greenland and West Antarctica are losing mass in a warming world, but signals from East Antarctica are less clear.
Raymo said the research helps show that "catastrophic collapse" of the East Antarctic ice is probably not a threat today.
"However, we do need to worry about Greenland and West Antarctica."
|Contact: Cheryl Dybas|
National Science Foundation