Earth, our warrior, is armed with an armour called the ozone layer. It is in the stratosphere, about 15-20 km from the Earth's surface, that this layer works hard to filter out harmful ultraviolet-B (UV-B) radiation which can be life-threatening for all the beings of this planet. It is one of the many reasons why life is possible on Earth. And that's why its depletion is a big concern. Because the armour is developing some serious chinks. September 16 is designated as International Day for the Preservation of the Ozone Layer by none other than the United Nations for this very reason.
The destruction of the ozone layer is heralded by chlorine and bromine atoms. Just one chlorine atom can destroy 1,00,000 ozone molecules! These destructive gases are mostly released by products with chlorofluorocarbons (CFCs), hydrochlorofluorocarbons (HCFCs) and others which are in our refrigerants for refrigerators, propellants for aerosol sprays and more. Excessive usage of these has created these holes and news has it that the beautiful and mesmerising Northern Lights might have also contributed to the depletion this layer.
In some good news, in January 2021, it was reported that the 2020 Antarctic ozone hole closed, but this only means we need to keep vigil and ensure that there are no chinks in our ozone armour.