Ozone hole: One of the longest-lived on record is about to close

By Adam Vaughan

One of the longest-lived ozone holes on record is expected to close this Wednesday after several weeks of exposing wildlife and people in Antarctica to very high levels of ultraviolet radiation. 

The Montreal Protocol’s ban on gases, including CFCs, causing the destruction of the ozone layer have put the hole on track to heal by around the middle of the century. But the swing this year is a reminder of how much the ozone layer can vary annually depending …