Ice sheets in Antarctica may be melting faster than previously predicted and could contribute three feet of sea level rise by 2100, nearly doubling the most recent prediction by the International Panel on Climate Change. That’s according to researchers from Penn State University and the University of Massachusetts, who published their predictions last week in the journal Nature.
The last report by the IPCC predicted that total sea level rise would be no more than three feet by 2100, and that Antarctica would not contribute substantially to that rise. Now, however, this new study suggests that Antarctica alone will contribute three feet in a business-as-usual scenario.
Why the difference? As National Geographic wrote last week, previous models were based primarily on historical data, while the new study is based on the physics of ice. In addition, the model also takes into account factors that were only recently recognized as being important to the stability of Antarctica’s ice, according to the New York Times.
The Western Antarctic ice sheet sits on bedrock hundreds to thousands of meters below the ocean surface. One factor that helps hold it together are floating ice shelves. But, warming ocean waters can “quickly erode ice shelves,” the authors wrote, leaving the ice sheet vulnerable without its “buttressing” support system.
The researchers also applied their new models to sea-level events in the past. In one case, they were able to accurately reproduce an event 125,000 years ago when seas rose 20 to 30 feet higher than they are today.
Robert DeConto, a lead author of the study from the University of Massachusetts told the Guardian that the new prediction could “spell disaster for many low-lying cities.” Boston, Hong Kong, London, Miami, New Orleans, New York City, Shanghai, Sydney and Venice are just some of the many cities that would be at risk. And disaster could come at a much sooner timeframe than previously predicted. Children born today would be faced with the consequences.
However, the paper’s authors note that if measures are taken to reduce greenhouse gas emissions, it would be possible to prevent the major ice sheet in West Antarctica from collapsing. The climate agreement signed in Paris would take steps in that direction, although would not go far enough.