Antarctic Ozone Hole Forms Unusually Early

NASA animation of the 2003 ozone hole forming over Antarctica.

A hole in the stratospheric layer of ozone over Antarctica has appeared earlier than usual in 2007, according to a report by the United Nations weather agency.

The World Meteorological Organization (WMO) said it is too early to tell if the ozone hole will become larger than the record size measured in 2006.

Geir Braathen, a senior scientific officer with the WMO's atmospheric research and environment program, said the ozone hole could stretch northward to reach the southern tip of South America by October.

Thinning of the ozone layer has been linked to increased exposure to the sun's damaging ultra-violet rays, which can cause skin cancer.

While use of ozone-depleting chlorofluorocarbons (CFCs) has waned due to a worldwide treaty restricting their use, the WMO says large amounts of chlorine and bromine remain in the atmosphere and are likely to keep causing holes in the protective layer for years to come.

Animation: NASA