The extent of the Antarctic Ozone Hole

The ozone hole over Antarctica was growing rapidly throughout the 1980s and early 1990s, as the data in the chart shows. At its largest, the ozone hole was more than 25 million square kilometers — slightly bigger than the size of Sub-Saharan Africa. The earth’s ozone layer is important as the ozone absorbs most of the sun’s ultraviolet radiation, and helps to keep Earth habitable.

Human emissions of ozone-depleting substances — mostly chlorofluorocarbons — were breaking down ozone high in the atmosphere. But in 1987, the world agreed to phase out these ozone-depleting substances by signing the Montreal Protocol. Since then, emissions have fallen close to zero. As a consequence, the ozone hole stopped growing in the late 1990s. It will take decades to recover fully, but it’s slowly starting to rebuild.