The ozone hole ‘is healing and may be closed by 2050’
THE hole in the Antarctic ozone layer is on the mend, scientists revealed yesterday.
After fluctuations in its recovery attributed to the effects of volcanic eruptions and bans on aerosol chemicals, they said they have found ‘the first fingerprints of healing’.
Experts now predict that the hole in the layer of protective gas in the Earth’s stratosphere could close permanently by 2050.
The study found the hole has shrunk by about 1.7million square miles since 2000, when ozone depletion was at its worst. That is a patch of sky roughly 18 times the area of the UK and represents a decline of about one-fifth, according to the British and American scientists behind the research.
The finding is based on measurements taken in the key month of September, when the hole grows larger. The study also found that it is now taking about ten days longer to reach its largest size.
Experts have attributed the shrinking to the 1987 Montreal Protocol, which banned the use of chlorofluorocarbons (CFCs) found in aerosols, refrigerators and cleaning products. The researchers also took account of the influence of volcanic eruptions on the ozone layer.
‘Observations and computer models agree – healing of the Antarctic ozone layer has begun,’ said Dr Ryan Neely, from the University of Leeds, who was part of the international team that conducted the study.
Professor Susan Solomon, of the Massachusetts Institute of Technology in the US, whose research led to the strengthening of the Montreal Protocol, said: ‘We can now be confident the things we’ve done have put the planet on a path to heal.
‘Aren’t we amazing humans, that we did something that created a situation that we decided collectively, as a world, “Let’s get rid of these molecules”? We got rid of them, and now we’re seeing the planet respond.’
The ozone layer acts as a natural sun block, absorbing ultraviolet rays from the sun and allowing plants and animals to survive on Earth. But ozone is sensitive to chlorine – a component of CFC – temperature and sunlight.
The new study, published in the journal Science, found that more than half the shrinkage of the ozone hole was due solely to the reduction in atmospheric chlorine.
If this reduction continues, there is no reason why, barring future volcanic eruptions, the ozone hole should not close permanently by mid- century, Professor Solomon said.