Scientists Say Recovery of the Ozone Layer May Take Longer Than Expected

By KENNETH CHANG

Published: December 7, 2005

SAN FRANCISCO, Dec. 6 - The layer of ozone in the earth's upper atmosphere, which protects life from harmful ultraviolet radiation but which has been damaged by artificial chemicals, may take a decade or two longer to recover than previously thought, scientists reported Tuesday.

Until now, the ozone layer had been expected to return to its 1980 condition by about 2050. But at a meeting of the American Geophysical Union here, the scientists said new measurements and computer simulations suggested that continuing use of the chemicals - chlorofluorocarbons, or CFC's - would delay the recovery until about 2065.