It’s 1985, Liz has been sitting on the throne for 33 years. Ireland will win all 5 nations, Like A virgin will top the charts and Super Mario Bros will land on home screens. It is also the year when an unexpected discovery will be made. It would revolutionize science, establishing one of the most successful global environmental policies of the 20th century. Joe Farman, Brian Gardiner and Jonathan Shanklin, three researchers from the British Antarctic Survey, examine more than 20 years of data. If their records are correct, stratospheric ozone levels have been falling since the 1970s. Farman suggests that a man-made compound called chlorofluorocarbons or CFCs, often found in aerosol sprays and cooling devices like refrigerators, could be responsible…
In 1987, the role of CFCs in the depletion of the ozone layer was confirmed beyond doubt. Aerial measurements reveal unprecedented volumes of ClO in Antarctica’s upper atmosphere, a product of the reaction between CFCs and ozone.
CFCs contain fluorine, carbon and chlorine. They were considered a marvelous discovery, insoluble in water, non-carcinogenic, non-toxic and non-flammable. It was even known to be relatively unresponsive in the lower atmosphere. However, upon reaching the upper atmosphere, the stratosphere, and in the presence of UV light, chlorine atoms break off and react with ozone molecules, O3, stealing an oxygen atom to form chlorine monoxide. Further reactions with bulk oxygen molecules effectively make this process endless, CFCs remain in the stratosphere and continually deplete our protective ozone layer. It also happens that the conditions encountered in Antarctica exacerbate this reaction.
A quick call to arms. By the end of 1987, the Montreal Protocol had been concluded, the declaration of the phasing out of substances that deplete the ozone layer. To date, 197 countries have signed the agreement. Ozone levels are rising and the hole is slowly healing, but we won’t see the full effects of the ban until 2050. CFCs take 50 years to break down, and the hole was huge, at its largest encompassing the entire Antarctica. .