The Antarctic ozone layer is slowly healing, scientists say. On September 9, it reached an annual maximum size of 8.83 million square miles, according to NASA and the National Oceanic and Atmospheric Administration (NOAA).
Although this is a large area, it is smaller than in many previous years, making it the fifth smallest ozone hole since 1992. Scientists say the recovery is happening because of the Montreal Protocol, an international agreement that banned chemicals that harm the ozone.
If this trend continues, the ozone layer could fully recover later this century.