Ozone hole over Antarctica on the road to recovery

Last Updated: May 17, 2011, 13:04 PM IST

London: Researchers in Australia have claimed that the hole in the ozone layer over Antarctica is on the road to recovery, 22 years after the Montreal Protocol to ban chlorofluorocarbons (CFCs) and related ozone-destroying chemicals came into force.

The team is the first to detect a recovery in baseline average springtime ozone levels in the region.

"I think this is the first convincing observationally-derived evidence of the ozone rebound," the Nature quoted Adrian McDonald, an atmospheric scientist at the University of Canterbury in Christchurch, New Zealand, as saying.

"It`s the first where the statistical significance is high enough, and you can see the pattern well enough, that you feel comfortable in believing it," added McDonald.

The results of Murry Salby, an environmental scientist at Macquarie University in Sydney, Australia, revealed a fast decline in ozone levels until the late 1990s, then a slow rebound that closely matches what theoretical calculations had predicted, said David Karoly, a climate scientist at the University of Melbourne, Australia.

"It is the sort of result that was expected, but is the first to provide detection of an increase in Antarctic ozone levels," he said.

Salby`s data reveal that average springtime Antarctic ozone levels have already recovered by 15 percent since the late 1990s. However, projecting forward, natural weather-related fluctuations mean that even as late as 2085, ozone will still drop below 1980 levels for at least one year in every 10.