"Ozone Layer Faces Record Loss Over Arctic"

"GENEVA -- The depletion of the ozone layer shielding Earth from damaging ultraviolet rays has reached an unprecedented low over the Arctic this spring because of harmful chemicals and a cold winter, the U.N. weather agency said Tuesday.

The Earth's fragile ozone layer in the Arctic region has suffered a loss of about 40 percent from the start of winter until late March, exceeding the previous seasonal loss of about 30 percent, the World Meteorological Organization said.

The Geneva-based agency blamed the loss on a buildup of ozone-eating chemicals once widely used as coolants and fire retardants in a variety of appliances and on very cold temperatures in the stratosphere, the second major layer of the Earth's atmosphere, just above the troposphere."

John Heilprin reports for the Associated Press April 5, 2011.