Earth Equity News

Seven Foot Rise in Sea Levels Likely this Century. By Rob Young and Orrin Pilkey, YaleEnviro360, January 14, 2010. "Given the complexities of forecasting how much the melting of the Greenland and West Antarctic ice sheets will contribute to increases in global sea level, the IPCC chose not to include these giant ice masses in their calculations, thus ignoring what is likely to be the most important source of sea level rise in the 21st century. Arguing that too little was understood about ice sheet collapse to construct a mathematical model upon which even a rough estimate could be based, the IPCC came up with sea level predictions using thermal expansion of the oceans and melting of mountain glaciers outside the poles. Its results were predictably conservative -- a maximum of a two-foot rise this century -- and were even a foot lower than an earlier IPCC report that factored in some melting of Greenland's ice sheet.

"The message for the world's leaders and decision makers is that sea level rise is real and is only going to get worse. Indeed, we make the case in our recent book, The Rising Sea, that governments and coastal managers should assume the inevitability of a seven-foot rise in sea level. This number is not a prediction. But we believe that seven feet is the most prudent, conservative long-term planning guideline for coastal cities and communities, especially for the siting of major infrastructure; a number of academic studies examining recent ice sheet dynamics have suggested that an increase of seven feet or more is not only possible, but likely. Certainly, no one should be expecting less than a three-foot rise in sea level this century." Rob Young is director of the Program for Developed Shorelines at Western Carolina University. Orrin Pilkey, Professor Emeritus, is with the Duke University Division of Earth and Ocean Science.