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Ozone Layer Protection

The 2025 Antarctic ozone hole closed on 1 December — the earliest closure since 2019. It’s the fifth-smallest hole since recovery began in 1992. This article covers ozone layer protection, from the Montreal Protocol to India’s own commitments under it.

mcqquestion.com The Ozone Layer’s Long Repair
EnvEco0017
16 SEP 1987
Montreal Protocol Signed
46 countries agree to phase out CFCs
1992
Controls Take Effect
Ozone-hole recovery tracking begins
21 SEP 2021
India Ratifies Kigali
Extends the Protocol to cover HFCs
1 DEC 2025
Earliest Closure Since 2019
5th-smallest Antarctic hole since 1992
Full recovery projected: Antarctic by 2066, Arctic by 2045, rest of world by 2040 — if current policies hold.
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📑 Contents

Timeline

  • 16 September 1987: The Montreal Protocol is signed by 46 countries, to phase out ozone-depleting substances.
  • 1992: Full controls take effect. Ozone-hole recovery tracking begins from this year.
  • 21 September 2021: India ratifies the Kigali Amendment, extending the Protocol to cover HFCs.
  • 1 December 2025: The Antarctic ozone hole closes — its earliest closure since 2019, and the fifth-smallest hole since 1992.

Must Know

🏛️ Must Know
The Montreal Protocol and Its Progress
  • Signed The Montreal Protocol was signed on 16 September 1987, to phase out ozone-depleting substances like CFCs.
  • Progress Over 99% of controlled ozone-depleting substances have been phased out worldwide since then.
  • 2025 Antarctic Hole The 2025 Antarctic ozone hole was the fifth-smallest since 1992. It closed on 1 December, the earliest closure since 2019.
  • Full Recovery Timeline The ozone layer is projected to fully recover to 1980 levels. Antarctica by 2066, the Arctic by 2045, and the rest of the world by 2040.

Good to Know

📘 Good to Know
The Kigali Amendment and India’s Timeline
  • Kigali Amendment The Kigali Amendment (2016) added HFCs to the Protocol’s coverage. HFCs don’t harm the ozone layer, but they are powerful greenhouse gases.
  • India Ratifies India ratified the Kigali Amendment on 21 September 2021.
  • India’s Baseline India’s HFC baseline is the average production and consumption across 2024, 2025, and 2026. A freeze at that level begins in 2028.
  • India’s Reduction Schedule After the freeze: 10% by 2032, 20% by 2037, 30% by 2042, and 85% by 2047.
📝 Previous Year Questions
UPSC CSP 2023 — Uses of Hydrofluorocarbons
  • UPSC 2023 A statement-based question on which uses of hydrofluorocarbons (aerosols, foam agents, fire retardants, lubricants) are correct. View this question.
UPSC CSP 2015 — What the Montreal Protocol Controls

Test Yourself

1. On what date was the Montreal Protocol signed?

 

Great to Know

🌟 Great to Know
Why the Protocol Worked
  • Two Treaties in One Ozone protection and climate protection now run through the same treaty. Kigali turned a pure ozone agreement into a climate one too, since CFC replacements turned out to be potent greenhouse gases.
  • Built to Be Strengthened The Protocol succeeded partly because it was built to be strengthened. Later amendments, like Kigali, could add new substances without renegotiating the whole treaty.
  • India’s Long Runway India’s phase-down math gives industry a long runway. The baseline is set now, the freeze starts in 2028, and the final 85% cut isn’t due until 2047.
  • Related For the mitigation-adaptation framework and Kyoto Protocol angle, see EnvEco0002 — Climate Change, EIA and Renewable Energy.

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