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What is Ozone Depletion? Facts, causes and effects of Ozone Depletion explained

What is Ozone Depletion? Facts, causes and effects of Ozone Depletion explained


  • GS 3 II Environment II Climate Change II Ozone Depletion

Why in the news?

Ozone depletion is one of the most serious damage caused in the atmosphere it is often in news due to damage caused to environment due to ozone depletion

What is Ozone depletion?

  • To understand the ozone layer, it would be helpful to know the different layers of the atmosphere.
    • Troposphere: The first layer stretching approximately 10 kilometers upwards from the earth’s surface is known as the troposphere. A lot of human activities such as gas balloons, mountain climbing, and small aircraft flights take place within this region.
    • Stratosphere: The stratosphere is the next layer above the troposphere stretching approximately 15 to 60 kilometers.
    • Ozonosphere:Lower region of the stratosphere containing a relatively higher concentration of ozone is called Ozonosphere.

Causes of ozone depletion:

  • The cause of ozone layer depletion is human activity, specifically, human-made chemicals that contain chlorine or bromine. These chemicals are widely known as ODS, an acronym for Ozone-Depleting Substances.
  • Ozone depletion occurs when the natural balance between the production and destruction of stratospheric ozone is tipped in favour of destruction. Although natural phenomena can cause temporary ozone loss, chlorine and bromine released from man-made compounds such as CFCs are now accepted as the main cause of this depletion
  • The chief ozone-depleting substances include chlorofluorocarbons (CFCs), carbon tetrachloride, hydrochlorofluorocarbons (HCFCs) and methyl chloroform. Halons, sometimes known as brominated fluorocarbons, also contribute mightily to ozone depletion.
  • Natural Causes of Depletion of the Ozone Layer: The ozone layer has been found to be affected by certain natural phenomena such as Sun-spots and stratospheric winds. But this has been found to cause not more than 1-2% depletion of the ozone layer and the effects are also thought to be only temporary.
  • Man-made Causes of Depletion of the Ozone Layer: The main cause for the depletion of ozone is determined as excessive release of chlorine and bromine from man-made compounds such as chlorofluorocarbons (CFCs). CFCs (chlorofluorocarbons), halons, CH3CCl3 (Methyl chloroform), CCl4 (Carbon tetrachloride), HCFCs (hydro-chlorofluorocarbons), hydro Bromo fluorocarbons and methyl bromide are found to have a direct impact on the depletion of the ozone layer.

Serious Effects of Ozone Depletion:

  • Damage to Human Health: If the ozone layer is depleted, it means humans will be overly exposed to strong UV light. Overexposure to strong UV light causes skin cancer, cataracts, sunburns, weakening of the immune system and quick aging.
  • The Devastation to the Environment: Many crop species are vulnerable to strong UV light and overexposure may well lead to minimal growth, photosynthesis and flowering. Some of the crop species vulnerable to UV light include barley, wheat, corn, oats, rice, broccoli, tomatoes, and cauliflower just to name a few. Forests equally bear the brunt of ozone depletion.
  • The Threat to Marine Life: Certain marine life, especially planktons, is greatly impacted by exposure to strong ultraviolet rays. In the aquatic food chain, planktons appear high up. If planktons decrease in number due to ozone layer destruction, the marine food chain would be disrupted in many ways.Also, overexposure of sun rays could reduce the fortunes of fishers. On top of that, certain species of marine life have been greatly affected by overexposure to ultraviolet radiation at their early stage.
  • Effect on Animals: In domesticated animals, too much Ultraviolet radiation could also lead to skin and eye cancer.
  • Impacts Certain Materials: Materials like plastics, wood, fabrics, rubber are massively degraded by too much ultraviolet radiation

Solutions to Ozone Depletion:

  • Desist From Using Pesticides: Pesticides are great chemicals to rid your farm of pests and weeds, but they contribute enormously to ozone layer depletion. The surefire solution to get rid of pests and weeds is to apply natural methods. Just weed your farm manually and use alternative eco-friendly chemicals to alleviate pests.
  • Discourage Driving of Private Vehicles: The easiest technique to minimize ozone depletion is to limit the number of vehicles on the road. These vehicles emit a lot of greenhouse gases that eventually form smog, a catalyst in the depletion of the ozone layer.
  • Utilize Environmentally Friendly Cleaning Products: Most household cleaning products are loaded with harsh chemicals that find way to the atmosphere, eventually contributing to the degradation of the ozone layer. Use natural and environmentally friendly cleaning products to arrest this situation.
  • Prohibit the Use of Harmful Nitrous Oxide: The Montreal Protocol formed in 1989 helped a lot in the limitation of Chlorofluorocarbons (CFCs). However, the protocol never covered nitrous oxide, which is a known harmful chemical that can destroy the ozone layer. Nitrous oxide is still in use today. Governments must take action now and outlaw nitrous oxide use to reduce the rate of ozone depletion.

International Actions against ozone depletion:

  • Montreal Protocol: In 1985 the Vienna Convention established mechanisms for international co-operation in research into the ozone layer and the effects of ozone depleting chemicals (ODCs).On the basis of the Vienna Convention, the Montreal protocol on Substances that Deplete the Ozone Layer was negotiated and signed by 24 countries and by the European Economic Community
  • Australian chlorofluorocarbon management strategy: It provides a framework for the responsible management and use of CFCs in Australia
  • Environmental Protection (Ozone Protection)Policy2000: This WA policy aims to minimize the discharge of ozone-depleting substances into the environment, and has been extended to cover use of alternative refrigerants
  • United Nations Environment Programme
  • Ozone Protection and Synthetic Greenhouse GasManagement Act 1989 (and associated regulations and amendments)was implemented by the Commonwealth Government to meet its commitments under the Montreal Protocol.
  • Ultraviolet index forecast: The Bureau of Meteorology has developed a model to predict the amount of ultraviolet exposure and the times of day

Steps taken by India to prevent ozone depletion:

  • India signed and ratified the Vienna Convention for the Protection of the Ozone Layer in 1991 and the Montreal Protocol on Substances that Deplete the Ozone Layer in 1992
  • India completely phased out production and consumption of Chlorofluorocarbons, carbon tetrachloride and halons, man-made chemicals responsible for the depletion of the Ozone Layer. With this achievement, India has contributed significantly to this global environmental cause, by reducing 25,000 ozone depleting particles tonnes and a further potential of 23,000 ozone depleting particles.
  • Carbon tetrachloride, a harmful chemical is used by some of the largest steel manufacturing units in the country, to clean steel. Today, many steel companies, including the country’s largest public sector undertaking in the steel sector, use tetrachloroethene which is less harmful for the environment.
  • Manufacturers of metered dose inhalers have completely transitioned to ozone-friendly and affordable alternatives, demonstrating the potential for environment-friendly public health management in the country.
  • UNDP is supporting the Government of India in phasing out Hydrochlorofluorocarbons (HCFCs) by 2030, as part of the country’s commitment to the Montreal Protocol.


Ozone depletion gets worse when the stratosphere (where the ozone layer is), becomes colder. Because global warming traps heat in the troposphere, less heat reaches the stratosphere which will make it colder.In other words, global warming can make ozone depletion much worse right when it is supposed to begin its recovery during the next century. Maintain programs to ensure that ozone-depleting substances are not released and ongoing vigilance is required to this effect. In fact, global warming, acid rain, ozone layer depletion, and ground-level ozone pollution all pose a serious threat to the quality of life on Earth. They are separate problems, but, as has been seen, there are links between each. The use of CFCs not only destroys the ozone layer but also leads to global warming

Mains oriented question:

“Nature is India is not only have scientific values but also has scared beliefs but still nature is now taken for granted”. How far this statement is correct? Explain. (250 words)