The Ozone Hole

In 1984, scientists announced the discovery of an ozone hole over Antarctica. This phenomenon was traced to ozonedepleting chemicals such as CFCs. The ozone hole was touted as a harbingerof what was to become of the ozone layer worldwide. Thanks to efforts to reduce ozonedepleting chemicals, the ozone layer is mending itself. The ozone hole, however, has continued to persist. More than 20 years after its discov ery, the ozone hole still covers an area of about 24 million square kilometers— about the size of North America. Scientists are still trying to determine why the ozone hole persists, even though the ozone layer is regenerating.

The dark inner- blue area shows the hole in the ozone layer.