The hole in the Ozone layer over the Antarctic was discovered in the 1980s. It regularly tends to form in August of every year reaching its maximum size late September or early October before it fills again in mid-December. The size totally depends on the weather. But this year the hole has found to be larger than it was last year.
Experts warned that such is the damage to the ozone layer, which shields the Earth from harmful ultra-violet rays, it will only attain full recovery in 2075. On September 13, the hole covered an area of 27 million square kilometers, while in 2007, the maximum reached was 25 million square kilometers, said the WMO.
Ozone provides a natural protective filter against harmful ultra-violet rays from the sun, which can cause sunburn, cataracts and skin cancer and damage vegetation.
Its depletion is caused by extreme cold temperatures at high altitude and a particular type of pollution, from chemicals often used in refrigeration, some plastic foams, or aerosol sprays, which have accumulated in the atmosphere.
Most of these chemicals, chlorofluorocarbons (CFCs), are being phased out under the 1987 Montreal Protocol, but they linger in the atmosphere for many years.
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