Dramatic loss of ozone in the lower stratosphere over Antarctica was first noticed by a research group.
two United States chemists predicted that a class of chemicals called chlorofluorocarbons (CFCs), widely used in aerosol spray cans, would seriously damage the ozone
Folklore has it that when the first measurements were taken
international meeting in Montreal created the world's first environmental convention.
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
first global agreement to restrict CFCs came with the signing of the Montreal Protocol
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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European scientists conducted SESAME, the Second European Stratospheric Arctic and Mid-latitude Experiment.
ozone hole over Antarctica was arguably the largest on record, with average ozone levels over Antarctica the thinnest ever observed.
a decrease in the size of the ozone hole is expected and decreasing levels of ozone-destroying CFCs have already been observed
