An ice sheet model that includes previously under-appreciated processes indicates that sea level may rise almost 50 feet by the year 2500 due to Antarctic ice sheet melting if greenhouse gas emissions continue unabated. Penn State senior scientist David Pollard and colleagues reported the model in the journal Nature earlier this year.

Antarctica was the primary contributor to sea level rise in the past and may be the primary contributor in the future because much of its ice sits on ground. Floating ice, like that of the Arctic Ocean, is already in the water and if it melts, does not raise sea level. The Antarctic contribution will also probably dominate melt from the smaller Greenland Ice Sheet. While only parts of Antarctica will melt in the worst-case scenario, the melting suggested by the model would be sufficient to double the recent estimates by the Intergovernmental Panel on Climate Change for future sea-level rise over the next 100 years.

Members of the news media interested in talking to Pollard should contact A’ndrea Messer at 814-865-9481 or aem1@psu.edu.