The Antarctic ozone hole caused by pollutants has opened up earlier and more rapidly this year than ever before, the UN's World Meteorological Organisation reported yesterday.
The finding increases pressure on the world's environment ministers to agree on tough new restrictions on industrial and agricultural chemicals which strip out the earth's protective ozone layer. They are to meet in Vienna in December but preliminary negotiations have run into serious obstacles.
The thin layer in the upper atmosphere shields the earth's surface from harmful ultra-violet radiation. Each Antarctic spring for more than a decade the return of sunlight drives a complex chain of chemical reactions that result in more than half the ozone being destroyed over the frozen continent. The damage is repaired later during the southern hemisphere winter, with the ozone building up again.
World Meteorological Organisation officers told a Geneva press conference yesterday that the Antarctic ozone decline was the most rapid on record, at one per cent a day, and the hole now covered an area the size of Europe. It had reached twice the size it attained at this time of year in 1993 and 1995.
Scientists of the British Antarctic Survey, the organisation which first discovered the hole almost 10 years ago, said ozone readings at the UK's Faraday base were unexpectedly low.
Since 1987 nations have made a series of agreements on phasing out ozone- depleting chemicals and scientists have forecast that these should help the protective layer to begin a very gradual recovery around the turn of the century.
But the latest readings, combined with this year's record thinning of the ozone layer over the Arctic during the northern hemisphere spring, sound a warning to the Vienna negotiators.