Antarctic ozone hole widens

New measurements reveal a widening hole
(Photo: National Oceanic and Atmospheric Administration)

By environment correspondent Alex Kirby

The ozone hole over Antarctica has grown more rapidly than scientists had expected.

The World Meteorological Organisation (WMO), a United Nations body, says satellite observations of the sunlit part of Antarctica show an average decrease of about 30% in the total amount of ozone.

A WMO spokesman, Taysir al-Ghanem, said: "This is an alarming rate of decrease.

"It is double the amount we had observed two weeks ago, and this could lead to a much greater ozone hole."

The Earth's protective layer of ozone shields all living things against harmful ultra-violet (UV) radiation from the Sun.

The radiation is linked to increases in skin cancers, eye disorders and the suppression of the immune system.

Doubling

The WMO says: "The latest satellite observations in the sunlit portion of the Antarctic perimeter show an average decrease of about 30% in the total amount of ozone overhead when compared to the 1964-76 norms.

"This is double the 15% reported two weeks ago and unusual for this early period.

"The amount and extent of loss has appeared earlier than in previous years.

"The sunlit region surrounding Antarctica continues to have considerably less ozone than normal, and this has been demonstrated with both ground-based and satellite measurements.

"However, prevailing meteorological conditions in the stratosphere, particularly during the Austral spring, strongly influence the extent and intensity of ozone loss and may substantially reduce the total seasonal depletion."

Concern

WMO's ground-based and satellite instruments need sunlight to work, and the new measurements have been made as the Antarctic winter ends and the sunlight becomes stronger.

The chief scientist at Greenpeace UK, Dr Doug Parr, told BBC News Online: "These data show that depletion is happening earlier and is potentially longer-lasting, and that's a trend we've been seeing for the past few years.

Antarctic wildlife may face new stresses

"The seas around Antarctica are now going to be exposed to more UV radiation.

"The other question that bothers me is whether what is happening to the ozone shows some sort of feedback from climate change.

"We are ignorant of the effects of UV radiation on some marine organisms when they're developing, and for that reason this is worrying news."

The chief culprit in ozone depletion is a family of man-made gases, notably chlorofluorocarbons (CFCs), which were widely used in aerosols and refrigeration.

Agreement

Others, like halons, are used in fire extinguishers, while methyl bromide is a soil fumigant.

The international agreement on ozone-depleting substances is the Montreal Protocol, adopted in 1987. This aims to reduce and eventually eliminate emissions of the chemicals that do the damage.

Environmental groups say the Protocol's provisions will allow ozone depletion to continue for a dangerously long time. But many scientists believe that the damage is on its way to being arrested and reversed.