Question

If CFC's cause ozone holes and atmospheric gases are freely diffusible, then why don't these ozone holes get filled up from the surrounding atmosphere.

Answer 1

Ozone holes are increasing in size instead of getting filled up because of the continuous increase in the air pollution, that is continuously increasing the concentration of CFC's in the atmosphere. Presence of high level of CFC's in the atmosphere is not allowing the filling up of the holes istead increasing it.