Study: Earth's Polar Ice Sheets Vulnerable to Even Moderate Global Warming

New Analysis Indicates Rising Sea Levels could be Far Worse than Previously Predicted

12/16/2009

An additional 2 degrees of global warming could commit the planet to 6 to 9 meters (20 to 30 feet) of long-term sea level rise.

A new analysis of the geological record of the Earth's sea level, carried out by scientists at Princeton and Harvard universities and published in the Dec. 16 issue of Nature, employs a novel statistical approach that reveals the planet's polar ice sheets are vulnerable to large-scale melting even under moderate global warming scenarios. Such melting would lead to a large and relatively rapid rise in global sea level.

According to the analysis, an additional 2 degrees of global warming could commit the planet to 6 to 9 meters (20 to 30 feet) of long-term sea level rise.

This rise would inundate low-lying coastal areas where hundreds of millions of people now reside. It would permanently submerge:

New Orleans and other parts of southern Louisiana
much of southern Florida and other parts of the U.S. East Coast,
much of Bangladesh,
and most of the Netherlands

unless unprecedented and expensive coastal protection were undertaken.

And while the researchers' findings indicate that such a rise would likely take centuries to complete, if emissions of greenhouse gases are not abated, the planet could be committed during this century to a level of warming sufficient to trigger this outcome.

The study, "Probabilistic Assessment of Sea Level During the Last Interglacial Stage," was written by Robert Kopp, who conducted the work as a postdoctoral researcher in Princeton's Department of Geosciences and Woodrow Wilson School of Public and International Affairs; Frederik Simons, an assistant professor of geosciences at Princeton; Jerry Mitrovica, a professor of geophysics at Harvard; Adam Maloof, an assistant professor of geosciences at Princeton; and Michael Oppenheimer, a professor of geosciences and international affairs in Princeton's Woodrow Wilson School.

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