Antarctica's ozone hole: Jubilee Science
It’s 1985, Liz has been sat on the throne for 33 years. Ireland will win the 5 nations, Like A virgin will soar to the top of the charts and Super Mario Bros will hit household screens.It’s also the year that an unexpected discovery will be made. It will revolutionize science, establishing one of the most successful global environmental policies of the twentieth century. Joe Farman, Brian Gardiner and Jonathan Shanklin, three researchers from the British Antarctic Survey, stare at over 20 years worth of data. If their recordings are correct, stratospheric ozone levels have been on the decline since the 1970s. Farman suggests a man made compounds called chlorofluorocarbons or CFCs, often found in aerosols and cooling devices like fridges, could be responsible...
In 1987 the role of the CFC in ozone depletion is confirmed beyond doubt. Aircraft 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 thought to be a wondrous discovery, insoluble in water, non-carcinogenic, non-toxic and non-flammable. It was even known to be relatively unreactive in the lower atmosphere. However, upon reaching the upper atmosphere, the stratosphere, and in the presence of UV light, chlorine atoms break away which react with ozone molecules, O3, stealing an oxygen atom to form chlorine monoxide. Further reactions with loose oxygen molecules effectively make this process neverending, CFCs stay in the stratosphere and continuously deplete our protective ozone layer. It also just so happens that the conditions found in Antarctica exacerbate this reaction.
A quick call to arms. By the end of 1987 the Montreal protocol had been made, the declaration to phase out ozone depleting substances. To date 197 countries have signed the agreement. Ozone levels are on the rise 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 massive, at its biggest encompassing the entirety of Antarctica.
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