Saturday, February 05, 2011

Rising Seas Look Inevitable

by Sid Perkins for Science Now
It may be too late to stop the seas from eventually rising and flooding Earth's coastlines. Even if humans manage to eliminate carbon dioxide emissions completely by the year 2100, ocean warming set in motion by the end of this millennium could trigger the collapse of the West Antarctic Ice Sheet and flood New York City, Hong Kong, and other coastal cities, a new study suggests.
Sea level rises when meltwater from land-based masses of ice, such as glaciers, flows into the ocean. But sea level also increases when heat from the atmosphere gets mixed into the upper layers of the ocean, causing that water to expand. In recent decades, this thermal expansion has provided, on average, only about one-quarter of the 1.8 millimeters of sea level rise seen each year, but its contribution is increasing, studies suggest. Read More