Print Friendly, PDF & Email

Ozone hole is filling up

GS Paper 3

Syllabus: Environment and Conservation


Source: IE

 Direction: The article discusses the efforts made to repair the ozone hole and how these efforts paid off.



  • The ozone hole, previously thought to be the most serious threat to planetary life, is now predicted to be completely healed by 2066.
  • This is stated in an UN-backed scientific team report titled ‘Scientific Assessment of Ozone Depletion 2022’.


Key highlights of the report:

  • The ozone layer is predicted to return to 1980 levels over Antarctica by 2066, 2045 for the Arctic, and 2040 for the remainder of the planet.
  • The ozone hole has been steadily improving since 2000, thanks to the Montreal Protocol’s (1987) effective implementation.
    • The Montreal Protocol mandates countries to phase out production of all main ozone depleting substances (ODSs).
    • The Kigali Amendment (2016) to the Montreal Protocol aims to phase down 80-90% of the hydrofluorocarbons (HFCs) currently in use by 2050.
    • HFCs have replaced chlorofluorocarbons (CFCs) in industrial use and the amendment seeks to prevent additional 0.3 to 0.5 degree Celsius of global warming by the end of the century.
    • HFCs do not cause much ozone layer damage, which is why they were not originally prohibited, but they are extremely powerful greenhouse gases (GHGs).
  • Nearly 99% of the Montreal Protocol-banned substances have now been phased out of usage, resulting in a slow but steady rebuilding of the ozone layer.
  • The eradication of ODSs has a significant climate change co-benefit because these compounds are also potent GHGs, expected to prevent 0.5 to 1 degree Celsius of warming by 2050.


Is it possible to use the success of repairing the ozone hole to slow the rate of global warming?

  • The success of the Montreal Protocol in closing the ozone hole is widely mentioned as a model for climate action.
  • However, the parallels between the eradication of ODSs and the reduction of GHGs are limited because the usage of ODSs (though widespread) was limited to a few specific industries and their replacements were readily available.


The case of fossil fuels is very different:

  • CO2 emissions are directly related to energy production and it is produced by almost every economic activity.
  • Even so-called renewable energies, such as solar and wind, have significant carbon footprints due to the use of fossil fuels in their manufacturing, transportation, and operation.
  • Methane emissions, the other primary GHG, are primarily caused by agricultural operations and livestock.



  • The influence of reducing GHG emissions is not restricted to a few economic sectors, but affects the entire economy, as well as human lifestyles, habits, and behaviours.
  • Without a question, dealing with climate change is a considerably more challenging and complex problem than dealing with ozone depletion.

Insta Links:

Large year-round ozone hole over tropics


Prelims Links: (UPSC 2022)

In the context of WHO Air Quality Guidelines, consider the following statements:

  1. The 24-hour mean of PM2.5 should not exceed 15 ug/m³ and annual mean of PM 2.5 should not exceed 5 µg/m³.
  2. In a year, the highest levels of ozone pollution occur during the periods of inclement weather.
  3. PM10 can penetrate the lung barrier and enter the bloodstream.
  4. Excessive ozone in the air can trigger asthma.

Which of the statements given above are correct?

    1. 1, 3 and 4
    2. 1 and 4 only
    3. 2, 3 and 4
    4. 1 and 2 only


Ans: 2