World Ozone Day

History of World Ozone Day

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 properties of this chemical were explored extensively by British meteorologist G. M. B. Dobson, who developed a simple spectrophotometer with which stratospheric ozone from the ground could be measured. The photochemical mechanisms from which the ozone layer is formed were discovered by the British physicist Sydney Chapman in 1930. 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.

World Ozone Day timeline

1913

The Ozone Layer is Discovered

French physicists Charles Fabry and Henri Buisson make this amazing discovery.

1929

The Ozone Maximum Altitude is Determined

A British meteorologist develops a spectrophotometer by which the ozone’s maximum altitude can be determined.

1930

The Mechanism Behind Ozone Layer

Sydney Chapman discovers the mechanism of the formation of the ozone layer.

1987

The Montreal Protocol is Signed

The Montreal Protocol, which is the basis of World Ozone Day, is signed in 1987.

World Ozone Day FAQs

When is World Ozone Day?

World Ozone Day 2026 falls on Wednesday, September 16. This annual observance is a global call to action for environmental protection and awareness.

What is the Montreal Protocol?

The Montreal Protocol on Substances that Deplete the Ozone Layer is an international treaty designed to protect the ozone layer by phasing out the production of numerous substances responsible for ozone depletion. Signed in 1987, it is widely considered one of the most successful environmental agreements.

How has the ozone layer recovered?

Thanks to the Montreal Protocol, the ozone layer is slowly but steadily recovering. Scientists project that the ozone layer over the mid-latitudes will recover by around 2045, and the Antarctic ozone hole by approximately 2066.

Why is the ozone layer important?

The ozone layer is a vital region of Earth’s stratosphere that absorbs most of the Sun’s harmful ultraviolet (UV) radiation. Without it, life on Earth would be severely impacted by increased rates of skin cancer, cataracts, and damage to ecosystems.

How to Observe World Ozone Day

Conduct research on ozone layer depletion

It does not hurt to get intentional in learning more about ozone depletion. For World Ozone Day, read about the depletion of the ozone layer and its effects on our climate.

Spread awareness of this important topic

The more people are informed of the dangers of ozone layer depletion, the better chances we have at stopping it. So, go on and spread the word.

Join the conversation online

Contribute your opinion. Lend your voice to the cause by sharing information on your social media handles using the #WorldOzoneDay hashtag.

5 Important Facts About The Ozone Layer

How the word was coined

The word ‘ozone’ is derived from the Greek verb ‘Ozein,’ which means ‘to smell.’

It’s a pale blue gas that stinks

Ozone chemical is a blue gas that gives off a pungent smell and yes, it’s possible to smell it in the air.

It’s harmful when too close to earth

Ground-level ozone is harmful to humans as it can result in chest pain and difficulty in breathing.

The chemical composition of the ozone molecule

One molecule of ozone contains up to three atoms of Oxygen.

Its depletion causes global warming

The depletion of the ozone layer is the major factor in global warming today and is the biggest climate change concern.

Why World Ozone Day is Important

It creates awareness about the ozone layer

World Ozone Day gives us the opportunity to really study and think about the ozone layer. This is a subject that we can no longer ignore.

It is an opportunity for green innovations

World Ozone Day opens up the opportunity for individuals and nations to come up with innovations in Green Energy. Reliance to green energy will help to relieve the depletion of the ozone layer.

It is an opportunity to preserve the planet

World Ozone Day gives us the opportunity to learn about the ways we can all contribute to the preservation of our planet. It promotes a cause bigger than any individual and affects the whole of humanity.