Ozone recovery could face delays
The predicted recovery of the infamous hole in the ozone layer could take much longer than expected, according to research released this week.The hole has been making a steady recovery since an international ban on ozone-destroying CFCs, the Montreal Protocol, came into play in 1987.
While existing CFCs in the atmosphere continued to eat away at the ozone following the agreement, the situation peaked in 1997 and trends since then suggest the Antarctic hole is slowly healing.
Before this week's announcement there was a consensus view in the scientific community that the hole would have returned to pre-industrial proportions by 2050.
But according to researchers speaking at the American Geophysical Union meeting on Tuesday, these estimates could be off by as much as 15 years.
While CFCs have been phased out since the 1980s, and alternatives are readily and cheaply available, there still remain huge reservoirs of the chemicals in the Western world, particularly in America.
Although manufacture of the chemicals has been extremely limited in recent years there are still stockpiles which, under the agreement, can legally be used and at some point will lead to further emissions.
This means, say the geophysicists, that the hole is likely to remain until 2065.
The ozone layer acts as a protective membrane for Earth's atmosphere, filtering harmful rays from the sun like a giant sun screen.
While the research team did not predict the likely consequences of the slowed recovery it is possible it will have health implications for those living towards the poles, as the incidence of melanoma and other skin cancers is much higher in areas with limited protection.
By Sam Bond
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