The seasonal thinning of the ozone layer above the Arctic has been less pronounced this winter and spring than in previous years, the World Meteorological Organisation (WMO) said in Geneva today.
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Image of ozone hole over Antarctica, courtesy of NASA
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But the agency warned the phenomenon reflected natural variations and not a reconstitution of the ozone layer, which has been damaged by emissions of chlorofluorocarbon (CFC) gases.
The WMO said while ozone layer measurements over the Arctic were higher this winter than in previous years, they were still down by about five per cent from their pre-1980 levels, when the confirmed process of ozone layer destruction had not yet begun.
Higher ozone levels registered this spring were explained by the fact that stratospheric temperatures had been higher than normal in the region in recent months.
These relatively high temperatures had prevented formation of stratospheric polar clouds which cause and accelerate ozone layer destruction, a WMO statement explained.
AFP