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1970 damage to this protective layer caused by atmospheric pollution
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1974 chlorofluorocarbons (CFCs), widely used in aerosol spray cans, would seriously damage the ozone layer
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The ozone layer above the Antarctic has been particularly impacted by pollution since the mid-1980s.
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1985- British scientists produced the first direct evidence that this was actually happening.
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1987- the combination of continuing cold conditions with sunlight brought the greatest rate of ozone depletion.
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Spring 2006 discovered ozone levels over Antarctica the thinnst ever observed
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1987- agreed to freeze production at 1986 levels and gradually cut it back, eventually eliminating use of the chemicals