World Ozone Day is celebrated worldwide on September 16. It is the day of commemoration of the eventful day of the agreement by the UN which signed the Montreal Protocol on Substances that Deplete the Ozone Layer in 1987. The day is thus marked as the International Day for the Preservation of the Ozone Layer.
On World Ozone Day 2021, let’s have a look at the story of Ozone
The news on closing of ozone depletion in December 2020 was a temporary relief to the scientific community, it is a reminder to the nations of the world that they are not going to back down from their reserves. The Earth’s atmosphere, which is 78 percent nitrogen and 21 percent oxygen (in the dry air), is composed of gaseous compounds, aerosols, and even very fine dust particles. There were ideas and concerns raised by the Ozone Day message ’36 years of ozone layer protection.
Story of Ozone
Ozone (O3) is a highly reactive gas composed of three oxygen atoms. Ozone reacts with other substances very quickly because it is less stable than oxygen and is a better oxidizer. In addition, ozone differs from other gases in its ability to absorb ultraviolet and infrared radiation. We can use Volume Percentage to indicate the number of gases in the Earth’s atmosphere. Of these, the volume of gases such as nitrogen and oxygen remains largely unchanged up to about 80 km above the Earth’s surface. This region is called the homosphere. However, 90% of the ozone in the Earth’s atmosphere is found in the stratosphere between 12 km and 60 km above the Earth’s surface. The area where ozone is most abundant in this region is called the ozone layer. This layer absorbs 98-99% of the sun’s ultraviolet rays and protects organisms. Therefore, we can call this ozone stratospheric ozone (ozone found in the stratosphere) or good ozone. The next ten percent are found below 12 km above the ground which is called the troposphere and the ozone in this region cause harm to the living beings on earth. Thus the ozone in this region is called tropospheric ozone or bad ozone.
The ozone layer or ozone shield is a region of Earth’s stratosphere that absorbs most of the Sun’s ultraviolet radiation. It contains a high concentration of ozone in relation to other parts of the atmosphere, although still small in relation to other gases in the stratosphere. Ozone which exists about seven to 25 miles above the Earth’s surface, in the stratosphere acts as a sunscreen for the planet. The ozone layer absorbs 97 to 99 percent of the Sun’s medium-frequency ultraviolet light which otherwise would potentially damage exposed life forms near the surface.
In the late 1970s, scientists discovered a hole in the ozone layer, caused by gases that deplete the ozone layer. These gases are found in cooling technology including refrigeration and air conditioning. To protect the ozone layer, countries signed the Vienna Convention for the Protection of the Ozone Layer in 1985. While the awareness about ozone’s importance for Earthlings may have existed for decades now, the need to protect it is now direr than ever.
The 2020 Arctic ozone hole was also very large and deep and peaked at roughly three times the size of the continental US.
The Antarctic ozone hole usually reaches its peak between mid-September and mid-October. When temperatures start to rise high up in the stratosphere in late southern hemisphere spring, ozone depletion slows, the polar vortex weakens and finally breaks down and, by December, ozone levels usually return to normal.
How to protect the Layer
- Reduce the use of ozone-depleting substances that are not considered as consumption-worthy under the Montreal Protocol.
- Refraining from items that contain chlorofluorocarbons, hydrochlorofluorocarbons, halogenated hydrocarbons etc help to reduce the ozone harm in the planet. These substances are a threat to ozone layer.
- Inspect and maintain electrical appliances and get them serviced on a regular basis.
- ODS from refrigerators and air conditioners must be properly recovered and recycled in order to ensure that it is not released into the atmosphere.
- Appliances should be chosen with ‘energy star’ labels.
- Opting for public transport, cycling, walking, car-pooling instead of travelling in personal vehicles will be a brave step to protect our ozone layer.