Answer Writing Practice for UPSC IAS & UPPSC Mains Exam: Paper - IV (General Studies – III) - 01 October 2019

Answer Writing Practice for UPSC IAS Mains Exam

Answer Writing Practice for UPSC IAS & UPPSC Mains Exam

UPSC Syllabus:

  • Paper-IV: General Studies -III (Technology, Economic Development, Bio-diversity, Environment, Security and Disaster Management)

Q. What is Ozone Layer Depletion? Evaluate the efforts being made to protect the Ozone Layer? (250 words)

Model Answer:

  • Why in News?
  • Introduction
  • What is Ozone Layer Depletion?
  • Efforts to protect the Ozone Layer Depletion
  • Conclusion

Why in News?

Every year 16th September is marked as the International Day for Preservation of the Ozone Layer. The theme for 2019 was ‘32 Years and Healing.’ 


Ozone (O3) is a protective layer in the atmosphere of the Earth. It is found in the lower portion of stratosphere. The Ozone Layer acts as a shield to protect the earth against harmful ultraviolet (UV) radiation from the sun. Ozone is regarded harmful at ground level but stratospheric ozone plays a vital role in the protection of all living beings on Earth.

Ozone Layer Depletion:

The ozone layer depletion was first identified to be a potential problem in the early 1970s. It is the gradual thinning of Earth’s ozone layer in the upper atmosphere caused by the release of ozone depleting substances.

How ozone depleting substances and greenhouse gases affect the atmosphere

Ozone layer depletion causes increased UV radiation levels at the Earth's surface, which is damaging to human health. UV radiation also affects terrestrial and aquatic ecosystemsaltering growthfood chains and biochemical cycles.

Efforts to protect the Ozone Layer Depletion:

  • In 1985, countries adopted the Vienna Convention for the Protection of the Ozone Layer.
  • According to this Convention, the parties were to promote cooperation on the effects of human activities on the ozone layer and to adopt legislative or administrative measures against activities likely to have adverse effects on the ozone layer.
  • The Montreal Protocol on Ozone Depleting Substances in 1987 is regarded as the greatest effort and environmental success of United Nations towards protecting the Ozone Layer.
  • The objective of Montreal Protocol was to cut down the production and consumption of ozone-depleting substances, in order to reduce their presence in the atmosphere and thus protect the Earth's ozone layer.
  • The Montreal Protocol was amended by the Kigali Agreement. It came into force from 1st January 2019. This is a legally binding agreement between the signatory parties with non-compliance measures. It has divided the signatory parties into three groups-
  1. The first group consists of rich and developed economies like USA, UK and EU countries who will start to phase down HFCs by 2019 and reduce it to 15% of 2012 levels by 2036.
  2. The second group consists of emerging economies like China, Brazil as well as some African countries that will start phase down by 2024 and reduce it to 20% of 2021 levels by 2045.
  3. The third group consists of developing economies and some of the hottest climatic countries like India, Pakistan, Iran, and Saudi Arabia who will start phasing down HFCs by 2028 and reduce it to 15% of 2024-2026 levels till 2047.
  • The Kigali Agreement also provides for a multilateral fund for HFC reduction.


The recent detection of the ‘rogue’ production of CFC-11, one of the most powerful ozone depleting gases is a reminder that we should be vigilant. The actions taken through the Vienna Convention, the Montreal Protocol, and the successive amendments to the protocol were planet-saving steps. But it is also important to be watchful and not undo the good that has been done to the ozone layer.

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