A new study published in the journal Nature said sea levels could rise six feet or more if nothing is done to reduce carbon emissions, potentially inundating many coastal areas, submerging nations and remaking maps of the world.
The study focused on what will happen to the West Antarctic ice sheet, one of the most elusive aspects of sea-level science.
Scientists have long believed the ice sheet would melt from climate change and contribute to higher sea levels. But they believed that the melting, and the rising sea levels it would cause, could occur over many hundreds or even thousands of years.
The new study, by Robert DeConto, a geoscientist at the University of Massachusetts at Amherst, and David Pollard, a geoscientist at Pennsylvania State University, based its finding on models it developed from studying ancient sea-level and temperature changes. The scientists found that drastic sea-level rise could happen within a lifetime.
As alarming as the study might have seemed to the public and to policy-makers, Benjamin Horton, a coastal geologist at Rutgers University in New Jersey who studies sea level, told the Los Angeles Times it did not surprise many people in his field.
The obvious solution, Horton said, is to move quickly away from burning fossil fuels that contribute to climate change and rapidly expand solar, wind and other renewable forms of energy.
"We have a choice right now," he told the paper. "If we strongly mitigate against greenhouse gases we can keep the sea-level rise to a manageable level. These papers are not all doom and gloom. They are providing a warning, and we as a scientific community are trying to stress the urgency on climate change.
"This is a dire warning, a dire prediction, but we can do something about it."