Melting ice sheets now largest contributor to sea-level rise

BBC : A team led by Eric Rignot of NASA’s Jet Propulsion Laboratory and the University of California, Irvine, has just published the results of a 20-year study into the extent and causes of global sea-level rise. The gradual warming of Earth’s lower atmosphere raises sea levels in two ways—by warming seawater, thereby lowering its density, and by melting icecaps and glaciers, thereby increasing the amount of seawater. Until recently, the warming of seawater was the bigger contributor. Now, however, the melting of ice has taken the lead. On average, sea levels now are rising at a rate of 3 mm a year.