Context
- 16 September is observed as World Ozone Day, marking the adoption of the Montreal Protocol on Substances that Deplete the Ozone Layer in 1987.
Why Was the Montreal Protocol Needed?
The stratospheric ozone layer absorbs harmful Ultraviolet-B (UV-B) radiation. Certain man-made chemicals release chlorine and bromine in the stratosphere, which catalytically destroy ozone.
- Ozone depletion: Reduction in stratospheric ozone concentration.
- Ozone hole: A region of severe seasonal ozone depletion, most prominently over Antarctica.
- Major ozone-depleting substances (ODS): CFCs, halons, carbon tetrachloride, methyl chloroform, HCFCs and methyl bromide.
- Major impacts: Increased risk of skin cancer, cataracts and damage to ecosystems.
Montreal Protocol at a Glance
- Adopted: 1987; Entered into force: 1989.
- Objective: Protection of the stratospheric ozone layer.
- Focus: Phasing out Ozone-Depleting Substances (ODS).
- Nature: Legally binding international environmental treatyunder the Vienna Convention framework.
- Implementation: Different phase-out schedules for developed and developing countries.
- Multilateral Fund: Provides financial and technical assistance to developing countries.
- Kigali Amendment (2016): Entered into force: 1 January 2019, mandates the phase-down of HFCs, which are not ODS but are potent greenhouse gases.
What Does the Protocol Control?
The Protocol does not merely regulate emissions after production. It controls the production, consumption, trade and use of ODS.
Important substance groups
| Substance | Major historical use | Ozone significance |
| CFCs | Refrigeration, aerosols | Major ozone-depleting chemicals |
| Halons | Fire extinguishers | High ozone-depleting potential |
| HCFCs | Transitional refrigerants | ODS, though generally less damaging than CFCs |
| Methyl bromide | Fumigation | Ozone-depleting substance |
| HFCs | Refrigeration and air-conditioning | Do not deplete ozone, but are powerful greenhouse gases |
| Important CTC from this article for UPSC: Kigali Amendment Ultraviolet Rays |
Q. Consider the following statements regarding the Montreal Protocol:
1. The Montreal Protocol controls the production and consumption of ozone-depleting substances.
2. The Kigali Amendment regulates HFCs because they are major ozone-depleting substances.
3. The Multilateral Fund provides financial assistance to developing countries for implementing the Protocol.
Which of the statements given above is/are correct?
(a) 1 and 2 only
(b) 1 and 3 only
(c) 2 and 3 only
(d) 1, 2 and 3
Answer: (b) 1 and 3 only
Statement 1 is correct: The Montreal Protocol establishes controls on the production and consumption of ODS.
Statement 2 is incorrect: HFCs do not deplete the ozone layer; they are powerful greenhouse gases. The Kigali Amendment addresses their phasedown.
Statement 3 is correct: The Multilateral Fund supports developing countries in implementing Montreal Protocol obligations.