September 16: World Ozone Day

The World Ozone Day is also called the International Day for the preservation of the ozone layer. The day is being celebrated since 1994. The United Nations General Assembly proclaimed September 16 as World Ozone Day to commemorate the signing of Montreal protocol in 1987. The Protocol aims to reduce usage of substances that deplete ozone layer.


The Montreal Protocol was framed at the Vienna Convention for the Protection of the Ozone Layer. This year, 2020 marks the 35 years of Vienna Convention. Till date, Montreal Protocol is the only UN treaty that has been ratified by every country on the earth (197 members of the UN).

This year, the day is celebrated with the following theme

Theme: Ozone for life: 35 years of ozone layer protection


The Montreal Protocol has greatly helped to heal the ozone layer. The ozone layer is expected to return to pre-1980 values by mid-century. The Kigali Amendment came into force in 2019 in support of Montreal protocol. Kigali agreement works towards reducing hydrofluorocarbons, greenhouse gases.

Ozone Layer

In 1976, it was found that the chlorofluorocarbons being released due to anthropogenic activities is depleting the ozone layer. The ozone layer blocks UV rays from the sun and thus protects the earthly beings.

Kigali Agreement

According to the agreement, the countries agreed to reduce the usage of HFCs (Hydrochlorofluorocarbons) by 80% to 85% by 2040. The agreement came in to force in 2019.


Ozone is a form of oxygen with a chemical formula O3..90% of Ozone is found in stratosphere at a height of about 10 km to 40 km. While the rest of 10% is found near the earth’s surface and is called surface ozone

Surface Ozone Vs Ozone Layer

The Surface ozone is a health hazard to people living. Increased amounts of Ozone in the atmosphere, close to earth’s surface will affect breathing process and will aggravate asthma. Surface Ozone are considered as a pollutant.