"First North Pole Ozone Hole Forming?"

"Spawned by strangely cold temperatures, 'beautiful' clouds helped strip the Arctic atmosphere of most of its protective ozone this winter, new research shows.

The resulting zone of low-ozone air could drift as far south as New York, according to experts who warn of increased skin-cancer risk.

The stratosphere's global blanket of ozone—about 12 miles (20 kilometers) above Earth—blocks most of the sun's high-frequency ultraviolet (UV) rays from hitting Earth's surface, largely preventing sunburn and skin cancer.

But a continuing high-altitude freeze over the Arctic may have already reduced ozone to half its normal concentrations—and 'an end is not in sight,' said research leader Markus Rex, a physicist for the Alfred Wegener Institute for Polar and Marine Research in Bremerhaven, Germany."

Christine Dell'Amore reports for National Geographic News March 22, 2011.