27 April 2020

Introduction:

 A rare hole in the ozone layer spreading over 1 million square kilometre in area, was discovered by scientists earlier this month. The hole was understood to be a result of low temperatures at the North Pole. Had the record-breaking hole managed to move south with the air currents, it would have posed a direct threat to humans.  Copernicus’ Atmosphere Monitoring Service (CAMS) and Copernicus Climate Change Service (C3S), who implemented study on behalf of the European Commission, have now confirmed that the hole over the North Pole has healed itself.

Findings of the study: 

• The ozone layer hole over the Arctic at this time was caused by the strong and consistent polar vortex and the resulting concentration of more ozone-depleting chemicals than usual.
• Healing of the hole in the Earth’s ozone layer has nothing to do with the ongoing reduction in pollution due to COVID-19 lockdown.
• It is because of the polar vortex-high altitude currents bringing cold air to the Polar Regions- it is a self –healing process.

How did the ozone layer heal?

• Polar vortex helped the healing of ozone layer.
• Polar vortex is a large area of low pressure and the cold air surrounding both of Earth’s poles.
• It is believed that the polar vortex, the high-altitude currents that are responsible for bringing cold air to the Polar Regions, is responsible for the healing of the layer.
• CFC gases which are responsible for depleting ozone layer were banned by the Montreal Protocol 1987. This has shown good results and is also one of the factors for the present healing of the ozone hole.

Why healing of the ozone hole is good news?

• The ozone layer is approximately 7 to 25 miles above the Earth’s surface and acts as a “sunscreen” for the planet.
•  It keeps out harmful ultraviolet radiation from the sun that has been linked to skin cancer, cataracts, immune system suppression and can also cause damage to plants.

About Montreal Protocol:

The Montreal Protocol is an international treaty designed to protect the ozone layer by phasing out the production of numerous substances that are responsible for ozone depletion. It bans the use of CFCs which deplete ozone layer.

• It was agreed on 16th September 1987, and entered into force on 1st January 1989.
• It is legally binding.
• Signatories- 46.
•  Location – Montreal.

About CFCs:

These are a class of compounds of carbon, hydrogen, chlorine, and fluorine, typically gases used in refrigerants and aerosol propellants. They are harmful to the ozone layer in the earth’s atmosphere owing to the release of chlorine atoms on exposure to ultraviolet radiation.

Preceding Story:

According to EIA- (The Environmental Investigation Agency- a London based organisation.):

• Chinese have found ways to dodge legal compliance and continue to use CFC-11( trichlorofluromethane) because it’s a superior chemical when it comes to creating insulating foams.
• These foams have been in great demand in China because of the country’s construction boom. CFC-11 is also cheap and easy to make, compared to the legal alternatives.
• Beyond depleting the ozone layer, CFCs and their legal replacements hydrofluorocarbons (HFCs) are powerful greenhouse gases. Each molecule of the gases has thousands of times more impact in trapping the sun’s heat and warming the planet than carbon dioxide does.
• This is the cause of anomalies in healing of the 0zone layer.