Our Radiant Planet: Depletion of the Ozone Layer

Our Radiant Planet: Depletion of the Ozone Layer

Ozone is a relatively unstable form of molecular oxygen containing three oxygen atoms produced when upper-atmosphere oxygen molecules are split by ultra violet light. Stratospheric ozone is found in a broad band, extending generally from 15 to 35km above the earth. Although the ozone layer is surprisingly thin, it acts as a protective shield to the earth, as it filters out most of the harmful solar ultraviolet radiation (in particular UV-B) that would otherwise reach our planets surface.

Humans have damaged the ozone layer by adding molecules containing chlorine and/or bromine that lead to ozone destruction. The largest group among these are chloroflurocarbons (CFC's). At ground level, these molecules are very stable and have many uses in industrial and domestic applications, such as in spray cans, industrial solvents, degreasing compounds, and cooling in fridges. However when released into the stratosphere, such molecules can be broken down by energetic light rays (UV-C radiation) in a reaction that liberates an atom of chlorine, which destroys ozone by oxidising with the Ozone molecules, forming