WORLD OZONE DAY

WORLD OZONE DAY

Not a layer but a protector

World Ozone Day 2022 is observed under the theme Global Cooperation Protecting life on Earth. The theme is decided to save the life of people who survive on the Earth to make protect the ozone layer and our environment.

World Ozone Day, observed every year on September 16, is also known as the International Day for the Preservation of the Ozone Layer. The date was designated by the United Nations General Assembly in 1994, commemorating the date in 1987 when nations signed the Montreal Protocol on Substances that Deplete the Ozone Layer. The need to declare an action to preserve the ozone layer came as a result of the outset of its depletion.

The ozone layer is a region of the earth’s stratosphere absorbing most of the Sun’s ultraviolet radiation. It contains a higher concentration of ozone than other parts of the atmosphere, though compared to other gasses in the stratosphere, it is rather small. It is mainly found in the lower portion of the stratosphere, from about 10 to 22 miles above the earth, varying according to geography and seasons.

French physicists Charles Fabry and Henri Buisson discovered the ozone layer in 1913. Measurements of the sun had shown that the radiation released from its surface to the ground on earth is usually consistent with a spectrum of a black body having extreme high temperatures, but there was no radiation below a wavelength measuring about 310 nanometers at the ultraviolet end of the spectrum. This led the scientists to deduce that the missing radiation at the ultraviolet end of the spectrum was being absorbed by something in the atmosphere. Upon several scientific tests, the spectrum of the missing radiation was eventually matched to just one known chemical, which was ozone.

The ozone in the earth’s stratosphere comes about as a result of ultraviolet light striking ordinary oxygen molecules with two oxygen atoms, thereby splitting them into individual oxygen atoms after which the atomic oxygen then combines with unbroken Oxygen.

When scientists, working in the late 1970s, discovered that humanity was creating a hole in this protective shield, they raised the alarm. The hole – caused by ozone-depleting gases (ODSs) used in aerosols and cooling, such as refrigerators and air-conditioners – was threatening to increase cases of skin cancer and cataracts, and damage plants, crops, and ecosystems.

. The global response was decisive. In 1985, the world’s governments adopted the Vienna Convention for the Protection of the Ozone Layer. Under the Convention’s Montreal Protocol, governments, scientists and industry worked together to cut out 99 per cent of all ozone-depleting substances. This year, we celebrate 35 years of the Vienna Convention and 35 years of global ozone layer protection.

World Ozone Day, held on September 16, celebrates this achievement. It shows that collective decisions and actions, guided by science, are the only way to solve major global crises. In this year after the coronavirus pandemic, that has brought such social and economic hardship, the ozone treaties’ message of working together in harmony and for the collective good is more important than ever. The slogan of the day, ‘Ozone for life’, reminds us that not only is ozone crucial for life on Earth, but that we must continue to protect the ozone layer for future generations.

Every year our students at STEM World School plant saplings in order to promote a healthier environment and also make posters on reducing usage of plastic bags.

As a teacher of this school, I always encourage my students to create awareness among the others regarding this global concern.. “One child, to one state, to one country, can create a big difference".      

- By Sayanti Chakraborty 

( Assistant Teacher, Department of Science, STEM World School)