In the stratosphere, 15-30 km above the earth’s surface, a high concentration of ozone is found in what we call the ozone layer. Despite its very low thickness (300 Dobson units, or about only three millimeters), it has an essential function for life on Earth as it protects us from the dangerous radiations of the Sun. More specifically, due to the chemical structure of ozone (O3), this layer can absorb a lot of UVB rays that would otherwise reach the earth in a density that would be harmful for life on our planet. Lucky us!
False-color view of total ozone over the Antarctic pole on 6 February 2023. The purple and blue colors are where there is the least ozone, and the yellows and reds are where there is more ozone. Source: NASA
However, this ozone layer faces challenges and is not homogeneous in space and time. In fact, in the 1980s, scientists discovered a large hole in this layer above Antarctica and attributed it to anthropogenic activities, more specifically to the use of chlorofluorocarbons (CFCs). CFCs are chemical substances that were widely used in refrigerant gases and as propellants in aerosol sprays, which were abundantly used in very common products such as hairsprays, refrigerators, aircon, ... It sounds pretty bad that we destroyed our protective layer for the use of these items, however, there is a silver lining: politicians and scientists came together and banned the use of all CFCs in the hope the ozone layer would repair itself.
Fast forward to current times, the ozone is slowly but surely repairing, and it is estimated that by 2050-2060 it should be completely restored. Although there is a long way to go, we are on the right path. Hooray for science!
Want to read more about this topic? Have a look at the detailed description of the discovery and action taken upon the discovery here. Or have a look at these nice graphs. Still want to read more? Than click here!
Written by Lotte De Maeyer
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