Human: I've heard that the ozone layer is getting thinner. What can we do to fix it? Assistant: 
The main cause of thinning of the ozone layer is the release of chlorofluorocarbons (CFCs) and other chemicals into the atmosphere. These substances are known as "ozone-depleting substances" because they destroy the ozone layer by breaking down the molecules of ozone. In order to stop this from happening, countries around the world have agreed to reduce or eliminate their use of these substances. This has helped to significantly reduce the amount of ozone depletion in the atmosphere.