Ozone hole could reach record size

The ozone hole has formed again over the Antarctic and is showing signs of growing toward record size, the UN’s weather organisation said today.

“It is developing quite rapidly this year, in a very similar manner to the record-breaking year 2000,” said Carine Richard-van Maele, spokeswoman of the World Meteorological Organisation in Geneva.

The hole, actually a thinner-than-normal area in the protective layer high up in the earth’s atmosphere, has been reforming at the end of Antarctic winter every year since the mid-1980s.

This year it had developed “some time during the month of August,” said Michael Proffitt, a leading expert on the ozone hole at WMO. “It’s a gradual process.”

“The ozone hole now appears to be 9.65 million square miles in area, 10% below the record size recorded in mid-September 2000,” Proffitt said.

He forecast that the hole would peak in size later this month.

The ozone hole forms in the polar vortex, the circular wind pattern that forms annually in the stratosphere over Antarctica.

Reduction of the ozone layer can let harmful ultraviolet rays from the sun reach the earth’s surface. Too much UV radiation can cause skin cancer and destroy tiny plants at the beginning of the food chain.

One cause of ozone depletion is the chlorine and bromine released by man-made chemical compounds such as chlorofluorocarbons, which were contained in some aerosols.

Although emissions of the chemicals have been curbed under a global accord, scientists predict it will take about 50 years for the ozone hole to close.