In a rare spurt of good news, the Copernicus Atmospheric Monitoring Service has reported that the largest hole in the ozone layer in the North Pole has finally closed. The ozone layer, which works to shield the Earth and absorb most of the Sun’s skin-cancer UV rays, developed several gaps due to chemicals being released by human industrial activity, primarily CFCs (formerly used in appliances like refrigerators). The most notable is the one which routinely forms over the Antarctic, while the Arctic one is lesser-known.
Atmospheric research and scientific awareness of this fact led to bans on CFCs around the world, and concerted efforts to restore the layer. In 2003, scientists announced that the depletion of the ozone layer appeared to be slowing down, which motivated countries to work harder towards that goal. An idea that was proposed was using hydrochlorofluorocarbons (HCFCs) which are less reactive and had a lesser negative impact on the ozone layer. These in turn are currently being phased out for hydrofluorocarbons (HFCs) and other compounds that have little to no impact on the ozone layer.
The 2019-2020 polar vortex, a wide expanse of swirling cold air, was much stronger and stabler than it has been in recent years, causing the concentration of more volatile and ozone-depleting chemicals than normal, creating the conditions for this unprecedented hole above the northern reaches of our planet.
According to a wing of the European Union, this closing has nothing to do with the reduction in pollution caused by the COVID-19 lockdown. Rather, the polar vortex has finally broken up, causing a temporary heatwave in the region and closing the hole.