A few weeks ago, over the Arctic, the biggest hole ever recorded formed in the ozone layer (a portion of the Earth’s atmosphere that shields the planet from UV radiation).
Now, just as suddenly as it formed, it closed. But despite what most people might think, it has nothing to do with the lockdown or the significant reduction in human activity and air pollution. Scientists say the pandemic is not the reason for the hole closing. So why now ?
WHAT IS THE REASON FOR THE HOLE CLOSING NOW ?
What we have to know is that a large ozone hole opens every autumn over the South Pole, but the conditions that allow such holes to form are much rarer in the Northern Hemisphere.
According to CAMS – Copernicus Atmospheric Monitoring Service, the hole “has been driven by an unusually strong and long-lived polar vortex (unusual cold air trapped for longer than unusual) that kept it open, and it is not related to air quality changes.” And now that the intense polar vortex has ended, the ozone hole has closed. Those same conditions may not happen next year.
BUT WHAT ABOUT THE ENDANGERED OZONE LAYER, THEN ?
Human activity and human-made chemicals – the chlorofluorocarbons – have been destroying the layer for the past century, eventually causing the famous hole that formed in Antarctica in the 80s. Therefore, in 1987, 197 countries signed an agreement to phase out such chemicals in order to prevent further damage. Which has contributed to a decrease of the size of the hole over Antarctica. Without those regulations, the apparition of the second hole over the Arctic could have posed a threat to human health.
The Southern Pole hole is said to be shrinking by 1-3% per decade, and it is likely that it won’t be healed until at least 2050.
But as the cause of the most recent hole over Arctic, experts pointed to unusual atmospheric conditions. They expected it to heal as temperatures increased, breaking down the Arctic polar vortex, thus allowing ozone depleted air to mix with ozone rich air from lower altitudes. They however are not sure what caused the wave of dynamics to be weaker this year.