Figure 1: A graph comparing ozone levels at the south pole to levels present before the formation of the ozone hole sourced from the NOAA Global Monitoring Laboratory [1].
The figure above is showing a comparison of ozone concentrations in the atmosphere above the South Pole between the years 1967 and 2017. The x axis is the year of measurement and the y axis is the percentage of increase or decrease from the reference level (average of values between 1962 and 1978). Three different values are plotted: the annual average in blue, the average across a reference month for each year (October) in light blue, and a trendline for the October measurements in red. The measurement was done via The Dobson Spectrophotometer at the South Pole, which measures ozone concentration by comparing incoming amounts of light from the sun at wavelengths that are strongly absorbed by ozone with those that are not [1].
Ozone concentrations have immense implications on human life. Observations at the South Pole are also important to establish the worldwide trend. Ozone strongly absorbs incoming ultraviolet light which can damage human DNA and lead to skin cancer in high doses [2]. Depletion in ozone layers worldwide would lead to increases in skin cancer rates and other skin diseases. This would also require people to stay away from sunlight more often and wear sunblock whenever possible to avoid these effects. Chlorofluorocarbons, chemicals commonly used in refrigerators and aerosol sprays since the 1960s, were discovered to be responsible for a depletion of ozone in the atmosphere in 1985 and were subsequently banned [2]. This can clearly be seen reflected in the data, as ozone at the south pole was on a downward trend since the 1960s, reaching a minimum in 1997. Although production was stopped earlier it took time for natural cycles to reduce the effects of chlorofluorocarbons and restore ozone. This process is still taking place, as shown by the gradual upward trend of ozone. While not all areas of the world were affected as significantly as the South Pole, the declining ozone concentration was still hazardous to all humans and it is for the better that it is being restored.
- US Department of Commerce. (2005, October 01). GML South Pole ozone hole. Retrieved April 09, 2021, from https://www.esrl.noaa.gov/gmd/dv/spo_oz/ozdob.html
- World of change: Antarctic ozone hole. (n.d.). Retrieved April 09, 2021, from https://earthobservatory.nasa.gov/world-of-change/Ozone