In the midst of all the talk about man's detrimental influence on the environment, there is one piece of good news: The concentration of the protective ozone in the atmosphere above the Arctic is increasing.
The ozone shield is a layer of special oxygen atoms located high in the stratosphere. These atoms absorb most of the sun's damaging ultraviolet radiation, the same kind of radiation that causes sunburn.
Ozone is made of three oxygen atoms bonded together. These bonds can be broken by a variety of natural chemicals such as chlorine, but man‑made chemicals released into the atmosphere also break the ozone apart. Chlorofluorocarbons, or CFCs, used as refrigerants, propellants in spray cans, and solvents are particularly good at this.
After much scientific scrutiny, public debate and treaties between many nations, CFCs were gradually eliminated from use and production by the mid‑1990s. Now, we are finally seeing the results of those efforts.
On The Mend
Scientists from 35 research institutes in 14 countries completed project RECONCILE in 2013. Their findings verified once again that chlorine‑containing compounds are indeed responsible for ozone depletion.
The scientists also used improved climate models to confirm that the ozone concentration is increasing. NASA estimated that ozone levels will return to normal in about 40 years. Even the ozone concentrations at the South Pole, where the ozone layer was thinnest, should be back to normal levels by the end of the century.
The ozone layer restoration is a good example of the length of time needed for environmental recovery. It can take decades for changes to show an effect. It's also an example of how nations can work together to correct global environmental problems.
"Ozone Layer Above North Pole Expected To Recover By End of Century" (ScienceDaily)
"Stratospheric Ozone Layer Depletion and Recovery" (National Oceanic and Atmospheric Administration)