The ozone layer
Ozone layer will recover to pre-1980 levels in 50 years plus
Depletion of the Earth’s protective layer of stratospheric ozone was one of the defining environmental concerns of the late 1980s, following the discovery of a major ozone “hole” over the Antarctic. But following the entry into force of the Montreal Protocol to the Vienna Convention for the Protection of the Ozone Layer in 1989 and a complete phase-out of chlorofluorocarbon production by 1996, the depletion of the ozone layer has slowed markedly. Without the Montreal Protocol, the Earth would have been on track to lose two thirds of its ozone layer by 2065, leading to dramatic increases in skin cancer. Instead, thanks to multilateral action, the ozone layer is recovering steadily and Antarctic ozone is likely to return to pre-1980 levels sometime between 2060 and 2075.