Part of the show Science Question and Answer - New Horizons Mission
Connor in Tillingham asked:
Could you tell me if the ozone hole is now getting smaller since CFCs have been banned?
It's not actually getting any smaller yet but it's stopped getting any bigger, which kind of amounts to the same thing. What we see is a lag between the CFCs or chlorofluorocarbons, which are implicated in causing the ozone hole, going into the atmosphere. Then they react over Antarctica and damage ozone and make the hole bigger. If you see the hole not getting any bigger then that means that the reaction causing it must be slowing down, and at the same time ozone's continuously being remade. So the two processes must now be in balance, meaning that if it keeps on slowing down, within the next few years the hole should start to shrink a little bit. But let's not be too over-confident or complacent about this because the ozone hole is about the size of the American continent.