Record ozone loss over Antarctica
This year's Antarctic ozone hole is deeper than ever before and started forming earlier than ever before, Greenpeace said on September 24.
The US National Oceanic and Atmospheric Administration has revealed that satellites and balloons released at the South Pole measured a drop of stratospheric ozone over Antarctica that was 15% greater than at the same time last year.
Satellite studies released a week later by the National Aeronautics and Space Administration confirmed a serious ozone loss. Preliminary results from NASA's Total Ozone Mapping Spectrometer on board the Nimbus-7 satellite showed that the area of the 1992 Antarctic ozone hole is the largest on record.
The previous surface area covered by low total ozone values typically has reached near 19.9 million square kilometres. On September 23, the surface area covered reached 23 million square km, an increase from 1991 of approximately 15%.
By comparison, the surface area of Australia is 7.7 million square km.
The next Montreal Protocol meeting in Copenhagen in November is unlikely to agree to anything near the necessary emergency phase-outs of ozone-depleting substances.
"If industry plans to allow continued production of the ozone-destroying so-called 'alternatives' — HCFCs — are not stopped by the Montreal Protocol, it will be 2060 before the ozone layer may return to 'normal'. By then it could be too late", said Dr Bill Hare of Greenpeace International.
"Even if governments agree to an emergency phase-out of all chlorine-based ozone-destroying chemicals by 1995 under the Montreal Protocol, the stratosphere will not return to normal until 2045.
The World Meteorological Organisation has said that ozone levels above Antarctica began to decline "unusually early" this year.
Dr Hare said that volcanic eruptions, principally Mount Pinatubo, combined with record levels of ozone-depleting chlorine, have contributed to this year's record Antarctic ozone destruction. But he noted that if the stratosphere was not already primed with chlorine from CFCs, the Pinatubo eruption would not have resulted in an ozone hole.
He said that alternatives to these chemicals were becoming available now. n