A simple introduction to this answer can revolve around a general statement about Ozone.

Ozone is a molecule that is made up of three oxygen atoms. A layer of this gas sits in our planet’s stratosphere between 15 and 30 kilometres above the surface. It absorbs a portion of the radiation from the Sun, preventing it from reaching the planet.

Ozone is a molecule that is made up of three oxygen atoms. A layer of this gas sits in our planet’s stratosphere between 15 and 30 kilometres above the surface.

It absorbs a portion of the radiation from the Sun, preventing it from reaching the planet. It also prevents UV-B radiation from reaching the Earth and harming humans and other living beings

Body

You may incorporate some of the following points in the body of your answer:

Montreal Protocol

• The 1989 Montreal Protocol is meant to protect the ozone layer of the upper atmosphere.
• A set of chemicals, mainly the chlorofluorocarbons or CFCs, which were being used in the air-conditioning and refrigeration industry earlier, were found to be damaging the ozone layer of the upper atmosphere.
• The extensive use had led to depletion of the ozone layer, and formation of an “ozone hole” over the Antarctic region.
• Montreal Protocol mandated the complete phase-out of CFCs and other ozone-depleting substances (ODS), which it has successfully managed to do in the last three decades.
• CFCs were gradually phased out, first by HCFCs, or hydrochlorofluorocarbons in some situations, and then by HFCs, which have little ozone-depleting potential.

The Kigali Amendment

• In 2016, countries agreed to include HFCs in the list of controlled substances under Montreal Protocol and decided on a schedule for its phase-down.
• If implemented successfully, the Kigali Amendment is expected to prevent about 0.5°C rise in global warming by the end of this century.