The Antarctic Ozone Hole
You will no doubt have heard of the hole in the ozone layer above the Antarctic. CFCs (chlorofluorocarbons) cause ozone depletion when they are released into the atmosphere. These gases were widely used in refrigerators and as propellant in aerosol sprays. The Montreal Protocol of 1987 effectively banned their use by most leading industrial nations, though a few nations have actually increased their use of CFCs since this time. Developed countries have been reducing their consumption of HCFCs and were due to completely phase them out by 2020. Developing countries agreed to start their phase out process in 2013 and are now following a stepwise reduction until the complete phase-out of HCFCs by 2030.
The extreme cold of the Antarctic may also be a factor in ozone depletion, as there is a similar hole over the Arctic.Read More: Melting Ice Sheets