Hole in ozone layer above the Antarctic is growing: Scientists warn of rising CFC levels

THE DEEPEST hole recorded in the Antarctic ozone layer has been detected by scientists working for the British Antarctic Survey (BAS). They warn that the situation could become progressively worse over the next 10 years.

Two-thirds of the protective ozone layer had been destroyed by the end of September - 10 days before scientists had expected to record this year's lowest values. This year's depletion may not be over yet.

Ozone provides a vital protection against the sun's ultra-violet radiation for all life on the surface. Increasing ultraviolet radiation could trigger blindness and skin cancers.

Dr Brian Gardiner, head of the ozone section of the BAS, warned that the concentrations of chlorofluorocarbons (CFCs), the chemicals responsible for ozone depletion, will continue to rise until the turn of the century. 'For all I know, it's going to get worse for 10 years,' he said.

Researchers had expected that there would be limits to the extent of ozone depletion, Dr Gardiner said. 'If you had asked us in 1987, when we looked at the vertical distribution of ozone, it seemed that depletion was confined to a certain height range, and so there was a limit to how much could be eaten away: only that middle layer.' Now, it appears, that idea is wrong.

Dr Gardiner warned: 'Lots of people think that everything is behind us because of the Montreal Protocol (which limits industrial CFC production).'

But all that has happened is that the rate of increase of CFCs has lessened, he said, adding: 'We are pouring more CFCs into the air every year than the atmosphere is losing.'

But ozone is only one problem and is relatively minor, Dr Gardiner said. 'We have always regarded the Antarctic ozone hole as a nice gesture by nature to have given us this warning in a far-off, sparsely populated area of the world.'

While a two-thirds depletion over Antarctica is comparatively easy to detect, there is a 10 to 15 per cent depletion over the highly populated northern mid-latitudes, which would have been much harder to detect had scientists not been alerted by the problems in the Antarctic.

The ozone hole does indicate how human activities can interfere with the earth's atmosphere and climate on a global scale. A potentially more serious example is global warming and this will have to be tackled early, Dr Gardiner said.

He hopes that 'in 50 years, our successors will not be asking 'why didn't these morons learn from the one question to deal with the other'?'