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Dramatic loss of ozone in the lower stratosphere over Antarctica was first noticed by a research group.
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two United States chemists predicted that a class of chemicals called chlorofluorocarbons (CFCs), widely used in aerosol spray cans, would seriously damage the ozone
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Folklore has it that when the first measurements were taken
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international meeting in Montreal created the world's first environmental convention.
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an international team returned from the Antarctic to reveal that the cause of the ozone hole was human-produced chlorine and bromine molecules escaping to the stratosphere
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first global agreement to restrict CFCs came with the signing of the Montreal Protocol
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an international meeting in London voted for a strengthened Montreal Protocol under which CFCs, halons and other ozone-destroying chlorine compounds would be phased out
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Period: to
European scientists conducted SESAME, the Second European Stratospheric Arctic and Mid-latitude Experiment.
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ozone hole over Antarctica was arguably the largest on record, with average ozone levels over Antarctica the thinnest ever observed.
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a decrease in the size of the ozone hole is expected and decreasing levels of ozone-destroying CFCs have already been observed