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International Day For The Preservation Of The Ozone Layer  – IMPRI Impact And Policy Research Institute

International Day for the Preservation of the Ozone Layer

Abhivyakti Mishra


The brittle gas shield known as the ozone layer, shields the Earth from the sun’s destructive ultraviolet rays, preserving life on the planet. In addition to protecting the ozone layer for current and future generations, the phaseout of controlled uses of ozone depleting substances and the resulting reductions have made a significant contribution to global efforts to combat climate change. By preventing harmful ultraviolet radiation from reaching Earth, these actions have also protected human health and ecosystems. Scientists first noticed a huge hole in the layer in 1985. Two years later, the Montreal Protocol was ratified by 46 nations, who pledged to gradually phase out the dangerous substances.


Montreal Protocol has turned 38 years; a worldwide collaboration, safeguarding earthly life.

On Ozone Day, when the treaty turns 38, we will reflect on how the Montreal Protocol put a stop to one of the greatest risks to humanity as a whole: the thinning of the ozone layer. The world came together when it was discovered that ozone-depleting gasses used in aerosols and cooling were causing a hole in the sky. They phased out these gasses and demonstrated the value of multilateralism and successful international cooperation. Now that the ozone layer is recovering, it can once more protect people from the sun’s ultraviolet rays.

Earth’s “sunscreen” that shields living things from excessive UV radiation emanating from the sun is 

actually it’s stratospheric ozone layer. The ozone layer has been harmed by the release of compounds that deplete the ozone layer. However, thanks to national and international efforts, the ozone layer is repairing itself and should be fully recovered by 2065.  

The Importance of Ozone Layer

The ozone layer has been discovered to be severely harmed by a number of regularly used compounds. Halocarbons are substances that include one or more halogen atoms (fluorine, chlorine, bromine, or iodine) bonded to one or more carbon atoms. The ozone depleting potential (ODP) of halocarbons containing bromine is often substantially higher than that of halocarbons containing chlorine. Methyl bromide, methyl chloroform, carbon tetrachloride, and chemical families known as halons, chlorofluorocarbons (CFCs), and hydrochlorofluorocarbons (HCFCs) are examples of man-made substances that have contributed the majority of the chlorine and bromine for ozone depletion.

Our bodies are shielded from the sun’s harmful ultraviolet (UV) rays by the ozone layer, which acts as an invisible barrier. In particular, the ozone layer shields us from UV-B radiation, or sunburn-causing UV rays.

Vienna Convention for the Protection of the Ozone Layer and the Montreal Protocol 

The world community set up a system for cooperation to take measures to protect the ozone layer once the ozone layer’s depletion was confirmed scientifically. On March 22, 1985, 28 nations adopted and signed the Vienna Convention for the Protection of the Ozone Layer, which put this into writing. This resulted in the creation of The Montreal Protocol on Substances that Deplete the Ozone Layer in September 1987.

The Montreal Protocol’s main goal is to protect the ozone layer by taking steps to reduce global consumption and production of substances that damage the ozone layer, with the ultimate goal of eliminating these substances in light of new scientific and technological information. It is organized around various categories of ozone-depleting chemicals. The chemical groups are included in the annexes to the Montreal Protocol text and are categorized by chemical family. In certain categories, the Protocol mandates the control of close to 100 substances. The Treaty specifies a timeline for the phasing-out of production and use of each category or annex of chemicals with the goal of finally eradicating them.

The Protocol’s timeline is applicable to using compounds that deplete the ozone layer. The amounts produced plus imported, less the quantities exported in any given year, are defined as consumption. Additionally, there is a deduction for actual destruction. The selected base-line year for the drug is used to calculate percentage reductions. Beyond the phase-out dates, the Protocol does not prohibit the use of recycled or currently in use controlled substances.

The Montreal Protocol on Substances that Deplete the Ozone Layer was signed on September 16, 1987, and the UN General Assembly declared that day to be the International Day for the Preservation of the Ozone Layer on December 19, 1994. On September 16, 1995, the holiday was first observed.

There are a few exceptions for necessary usage when no suitable alternatives have been discovered, such as halon fire-suppression systems used in submarines and aircraft or metered dosage inhalers (MDI) routinely used to treat asthma and other respiratory issues.

The Montreal Protocol on Substances that Deplete the Ozone Layer was signed in 1987, and the United Nations General Assembly declared September 16 the International Day for the Preservation of the Ozone Layer in 1994 (resolution 49/114).

Putting the Montreal Protocol into practice both developed and developing countries made good progress with the Montreal Protocol’s implementation. Most of the time, phase-out schedules were followed; in some cases, they were even met early. Initial focus was on substances like CFCs and halons that have a larger potential to deplete the ozone layer. Due to their decreased tendency to deplete the ozone layer and the fact that they have also been employed as temporary replacements for CFCs, the phase-out timeline for HCFCs was more slack.

The phase-out timetable for HCFCs was first announced in 1992 for both developed and developing nations, with the latter beginning with a freeze in 2015 and ending with a phase-out by 2030 in developed nations and 2040 in developing nations. The Montreal Protocol’s parties decided to speed up the phase-out of HCFCs for both developed and developing nations in 2007.

Universal Ratification

The Vienna Convention and the Montreal Protocol were the first treaties in United Nations history to receive universal acceptance on September 16, 2009.

Kigali Amendment

At their 28th Meeting of the Parties on October 15, 2016, in Kigali, Rwanda, the Parties to the Montreal Protocol on Substances that Deplete the Ozone Layer decided to phase down hydrofluorocarbons (HFCs).

The Recent Developments [1] 

According to a recent study, the Earth’s carbon sink—plants, flora, and soil—would not have been able to absorb and store as much carbon without the Montreal Protocol prohibition. This might have resulted in an additional 0.5–1°C increase in global warming.

According to the European Environment Agency, In September 2000, the ozone hole reached its biggest known size of 28.4 million km2. This area is roughly seven times the size of the entire EU. The Antarctic ozone hole’s size peaked at 24.5 million km2 in late September 2022. The Antarctic ozone hole has been comparable in size and duration to those observed in 2021 and 2020 up until the beginning of November 2022. 

According to the United Nations Environment Program, the phase-out of approximately 99% of the prohibited ozone-depleting compounds is confirmed in the quadrennial assessment report of the UN-backed Scientific Assessment Panel to the Montreal Protocol on Ozone Depleting compounds. Thus, the Montreal Protocol has been successful in protecting the ozone layer, resulting in a noticeable recovery of the ozone layer in the high stratosphere and a reduction in the amount of ultraviolet (UV) radiation that humans are exposed to.

If present policies are followed, it is anticipated that the ozone layer will return to 1980 levels (before the ozone hole appeared) by 2066 over the Antarctic, 2045 over the Arctic, and 2040 for the rest of the planet. Particularly between 2019 and 2021, changes in the Antarctic ozone hole’s extent were mostly caused by weather. But since 2000, the size and depth of the Antarctic ozone hole have been gradually increasing.

India’s Stance

According to a report by the Union Ministry of Environment, Forest and Climate Change, India has decreased its greenhouse gas (GHG) emissions by 465 million tonne CO2 equivalent as part of its effort to phase out ozone depleting substances (ODS). It further stated that by 2030, the nation’s GHG emissions are expected to have decreased by 778 million tonnes CO2 equivalent.

In 2010, India phased out ozone layer-depleting compounds like chlorofluorocarbons (CFC), carbon tetrachloride (CTC), and halons in accordance with the Montreal Protocol. More recently, in 2020, the nation completed the phase-out of HCFC-141b, one of the most potent ozone depleting substances after CFC and one of the kinds of hydrochlorofluorocarbons.

In 1991–1992, India ratified both the Vienna Convention, which calls on Parties to collaborate on ozone layer scientific research, and the Montreal Protocol. Around 100 produced ozone depleting substances, such as different kinds of CFCs, halons, CTCs, methyl chloroform, and methyl bromide, are regulated by the previous convention. India completed the phase-out of HCFC-141b, one of the most dangerous varieties of hydrochlorofluorocarbons used by businesses that make foam, in 2020.

The HPMP’s Stage III, the final phase-out plan for HCFCs, will go into effect between 2023 and 2030. All manufacturing sectors are expected to phase out HCFCs by 2025, while actions pertaining to the servicing sector will continue until 2030.

The Way Forward 

But the job on climate change is far from finished. The Kigali Amendment, which took effect in January 2019, requires countries to phase down the use of hydrofluorocarbons (HFCs), strong greenhouse gasses that are frequently substituted for the ozone-depleting materials that are prohibited in refrigerators and air conditioners. Up to 0.4°C of global temperature rise by the end of the century might be avoided by universal adherence to the Kigali Amendment.

Future cooling technology must be sustainable as global temperatures rise and cooling needs increase. The Protocol and its Kigali Amendment encourage the use of cooling technology that are both environmentally and economically favorable. Possible outcomes include improved climate and other advantages. For instance, by improving the availability and sustainability of cold chains, food loss and waste would be decreased, resulting in even lower carbon emissions and greater food security.

On this World Ozone Day, we honor the accomplishments of the Montreal Protocol, which through international cooperation safeguarded all forms of life, both now and in the future.


Increased UV-B radiation will be harmful to human health and have a significant negative impact on fish and plant productivity. People with lighter skin from higher latitudes are more prone to skin conditions than those with darker complexion. Over time, the skin pigmentation of people who live in low latitudes have developed to be able to absorb these dangerous radiations.

Eminent dermatologists in New Delhi claim that although skin cancer is uncommon in India, the surveys used to look for trends are insufficient. They stated controlled tests are being conducted to look at how crops respond to changing UV-B radiation concentrations. However, there haven’t yet been any field studies conducted in the nation.

With India’s Presidency of G20 2023, the tagline was “One Earth, One Family, One Future”, we need to understand that when it comes to the distribution of Earth’s resources and Earth’s disasters, we aren’t usually divided by borders, languages, race or ethnicities, we share the same Sun, and the same ozone layer that protects us from its harmful radiations, so we need the same collective efforts to not only help the Ozone layer recover but also to make sure that we don’t destroy our remaining shared resources. 


  1. International Day for Preservation of the Ozone Layer | 16 September, United Nations, Accessed on 28 August 2023 https://www.un.org/en/observances/ozone-day
  2. The Montreal Protocol on Substances that Deplete the Ozone Layer, UN Environment Program, Accessed on 28 August 2023 https://ozone.unep.org/treaties/montreal-protocol
  3. Ozone Layer Protection, United States Environmental Protection Agency, Accessed on 28 August 2023 https://www.epa.gov/ozone-layer-protection#:~:text=The%20stratospheric%20ozone%20layer%20is,been%20damaging%20the%20ozone%20layer
  4. Explained: Where Does India Stand in Saving Ozone Layer, Fact Checker, 17 September 2022, https://www.factchecker.in/explained/explained-where-does-india-stand-in-saving-ozone-layer-835244#:~:text=India%2C%20in%20its%20aim%20to,Environment%2C%20Forest%20and%20Climate%20Change.
  5. Funga: UN wants us all to say it along with ‘Flora & Fauna’, Down to Earth, 31 August 2023, https://www.downtoearth.org.in/news/funga-un-wants-us-all-to-say-it-along-with-flora-fauna–91440
  6. This year’s ozone hole is eight times bigger than India, set to last through November, India Today, 28 October 2021 https://www.indiatoday.in/science/story/this-year-s-ozone-hole-is-eight-times-bigger-than-india-set-to-last-through-november-1870457-2021-10-28
  7. India has successfully phased out production, consumption of ozone depleting substances: MoS Choubey, The Hindu, 16 September 2021 https://www.thehindu.com/news/national/india-has-successfully-phased-out-production-consumption-of-ozone-depleting-substances-mos-choubey/article36496299.ece
  8. Ozone layer recovery is on track, helping avoid global warming by 0.5°C, United Nations Environment Program, 9 January 2023, https://www.unep.org/news-and-stories/press-release/ozone-layer-recovery-track-helping-avoid-global-warming-05degc
  9. What is the current state of the ozone layer? European Environment Agency, 19 April 2023, https://www.eea.europa.eu/en/topics/in-depth/climate-change-mitigation-reducing-emissions/current-state-of-the-ozone-layer

Disclaimer: All views expressed in the article belong solely to the author and not necessarily to the organisation.

Acknowledgement: Author would like to thank Manya and Harshaa for their kind comments and suggestions to improve the article

Abhivyakti Mishra is a Research Intern at IMPRI. 

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