Even if humankind manages to limit global warming to 2 degrees C (3.6 degrees F), as the Intergovernmental Panel on Climate Change recommends, future generations will have to deal with sea levels 12 to 22 meters (40 to 70 feet) higher than at present, according to research published in the journal Geology.

The researchers, led by Kenneth G. Miller, professor of earth and planetary sciences in the School of Arts and Sciences at Rutgers University, reached their conclusion by studying rock and soil cores in Virginia, Eniwetok Atoll in the Pacific and New Zealand. They looked at the late Pliocene epoch, 2.7 million to 3.2 million years ago, the last time the carbon dioxide level in the atmosphere was at its current level, and atmospheric temperatures were 2 degrees C higher than they are now.

"The difference in water volume released is the equivalent of melting the entire Greenland and West Antarctic Ice Sheets, as well as some of the marine margin of the East Antarctic Ice Sheet," said H. Richard Lane, program director of the National Science Foundation's Division of Earth Sciences, which funded the work. "Such a rise of the modern oceans would swamp the world's coasts and affect as much as 70 percent of the world's population."