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What Happened To The Ozone Layer?
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Remember when the ozone layer had a massive, growing hole? Well, now it’s shrinking.
What is the Ozone layer
The ozone layer is a protective layer of gas in Earth’s stratosphere that absorbs most of the Sun’s harmful ultraviolet (UV) radiation. It is made up of ozone O₃ molecules and is located about 15 to 35 kilometers above Earth’s surface. This layer acts like a shield, protecting humans, animals, and plants from excessive UV exposure, which can cause health issues like skin cancer, cataracts, and harm to ecosystems by absorbing radiation from the sun. Ozone concentrations vary naturally with seasons and latitudes, these natural reductions has always been followed by a recovery however in the 1970’s scientists discovered that the ozone shield was being depleted well beyond natural processes.
What happened in the 1980s
Scientists noticed that in the 1980s, over the South Pole, the ozone layer was depleting fast. They suspected that certain chemicals in everyday products called chlorofluorocarbons (CFCs) were rising into the atmosphere and destroying ozone molecules. However, they weren’t sure until a scientist, Susan Solomon, went to the South Pole and confirmed it. Her work became the basis for the UN Montreal Protocol, which banned chlorofluorocarbons (CFCs) in 1987.
The chart above shows the high usage of ozone depleting gases in 1986 and by 2021 most of the gases have been phased out.
How does depletion happen ?
The main culprits when it comes to ozone depletion are chlorine and bromine. When these atoms come in contact with the ozone layer in the stratosphere, they destroy ozone molecules. One atom of chlorine or bromine can destroy 100,000 ozone molecules.
There are natural processes that accelerate the depletion of the ozone layer as well, like volcanic eruptions which emit gases like Hydrochloric acid and Hydrogen fluoride. When these gases reach the stratosphere…
