Ozone hole is bigger than it has ever been

[KevinTheOmnivore]

http://news.ft.com/servlet/ContentSe...=1012571727085

Ozone hole is bigger than it has ever been

By Clive Cookson in Manchester
Published: September 12 2003 19:45 |
Last Updated: September 12 2003 19:45

The Antarctic ozone hole is bigger than it has ever been at this time of year, threatening populated regions of south America and New Zealand with harmful levels of ultraviolet radiation.


Last year's hole was smaller than those recorded over the previous decade, leading to hopes that the protective ozone layer in the upper atmosphere was beginning to recover from its destruction by man-made CFC chemicals. But early observations reported on Friday to the British Association science festival at Salford University show that the hole, which appears every southern spring, is returning with a vengeance. The findings suggest that reduction of CFCs will take longer than expected to benefit the ozone layer.

Alan Rodger, who runs the British Antarctic Survey ozone-monitoring programme, said: "Last year's smaller hole should be regarded as exceptional and clearly a one-off event. It was... nothing to do with any reduction in ozone depleting chemicals."

The concentration of ozone destroying chemicals at the Earth's surface has fallen since 1994, following international agreement to phase out CFCs and related compounds through the Montreal Protocol. But levels in the stratosphere lag behind the surface by several years.

Dr Rodger said they are probably near their peak. "We predict that it will be a decade or more before we can say unambiguously that the ozone hole is recovering - assuming that the decline in ozone depleting chemicals continues," he said.