Sea level rises of 70 feet forecast

Future generations could see sea levels rise up to 70 feet even if mankind limits global warming to 3.6 degrees Fahrenheit, US scientists say. Researchers led by Rutgers University earth science Professor Kenneth G. Miller said their finding came from an analysis of rock and soil cores in Virginia, Eniwetok Atoll in the Pacific and New Zealand from the late Pliocene epoch, 2.7 million to 3.2 million years ago, when the carbon dioxide level in the atmosphere matched the current level and atmospheric temperatures were 3.6 degrees F higher than now. Their analysis found the conditions then had created significant sea level rises due to global melting of ice. "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 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." The research shows the sensitivity of the Earth's great ice sheets to temperature change, Miller said, suggesting even a modest rise in temperature results in a large sea-level rise. "The natural state of the Earth with present carbon dioxide levels is one with sea levels about 20 meters [65 feet] higher than at present," he said. However, he said, "You don't need to sell your beach real estate yet, because melting of these large ice sheets will take from centuries to a few thousand years. The current trajectory for the 21st century global rise of sea level is 2 to 3 feet due to warming of the oceans, partial melting of mountain glaciers, and partial melting of Greenland and Antarctica."