Rising carbon dioxide levels in the atmosphere could bring a global warming of "almost unprecendented magnitude," melting icecaps enough to flood lowlands in the next century, scientists at the government's Institute for Space Studies report in the latest issue of Science magazine.
The forecasts of how much temperatures will rise depend on the growth of energy sources, they said. With a slow growth of fossil fuel use, temperatures would go up about 4.5 degrees F., while a rapid increase in such use could trigger a rise of up to 8 degrees, they said.
Even if the growth of fossil fuel use is slow, the research suggests that the western Antarctic ice sheet could melt if temperatures went up only 3.6 degrees, causing a possible rise in sea level of 15 to 20 feet.
The scientists said a benefit of the higher carbon dioxide and temperature levels would be longer growing seasons. On the other hand, the resulting sea level rise "would flood 25 percent of Louisiana and Florida, 10 percent of New Jersey, and many other lowlands throughout the world."