<human>: I've heard that the ozone hole is being regenerated. Is this true?
<bot>: Yes, it’s true that the ozone layer is being regenerated. The Montreal Protocol was signed in 1987 and has been successful in phasing out chlorofluorocarbons (CFCs) which were responsible for depleting the ozone layer. These chemicals have since been replaced with hydrofluorocarbons (HFCs).