International Environmental Agreement

Montreal Protocol:
Guardian of the Ozone Layer

Explore the landmark treaty that's healing our planet's protective shield and its ongoing mission to protect life on Earth.

Discover More

A Milestone in Global Cooperation

Montreal city skyline, symbolic of the Protocol's adoption location

Adoption and Entry into Force

The Montreal Protocol on Substances that Deplete the Ozone Layer was adopted in Montreal, Canada, on September 16, 1987, under the framework of the Vienna Convention for the Protection of the Ozone Layer. It officially entered into force on January 1, 1989.

Signifying its importance, September 16th is celebrated annually as the International Day for the Preservation of the Ozone Layer (World Ozone Day).

Universal Success

The Montreal Protocol is widely regarded as one of the most successful international environmental agreements and boasts universal ratification. India became a Party to the Montreal Protocol in June 1992.

Core Objective: Protecting Our Shield

The primary goal of the Montreal Protocol is to protect the stratospheric ozone layer by systematically phasing out the production and consumption of numerous substances that are responsible for ozone depletion (Ozone Depleting Substances - ODS).

Key Features & Mechanisms

The Protocol lists specific ODS in its Annexes (A, B, C, E, F) and establishes legally binding timetables for Parties to phase out their production and consumption. Different schedules apply to developed (non-Article 5) and developing (Article 5) countries, recognizing common but differentiated responsibilities.

Examples of Controlled Substances:
  • Chlorofluorocarbons (CFCs): e.g., CFC-11, CFC-12. Used in refrigerants, aerosols. Largely phased out.
  • Halons: Used in fire extinguishers. Very high ODP. Largely phased out.
  • Carbon Tetrachloride (CTC): Solvent. Phased out.
  • Methyl Chloroform: Solvent. Phased out.
  • Hydrochlorofluorocarbons (HCFCs): Transitional substitutes for CFCs. Lower ODP but potent GHGs. Currently being phased out (2030 for developed, 2040 for developing countries).
  • Methyl Bromide: Fumigant. Phased out for most uses (QPS allowed).
  • Hydrofluorocarbons (HFCs): Not ODS, but potent GHGs. Added via Kigali Amendment.

The Principle of Common But Differentiated Responsibilities (CBDR) is recognized by providing developing countries (Article 5 Parties) with grace periods for phasing out ODS and access to financial and technical assistance through the Multilateral Fund.

Established in 1991, the MLF provides financial and technical assistance to Article 5 country Parties to help them meet their ODS phase-out obligations. It is funded by contributions from developed (non-Article 5) country Parties and is considered a key factor in the Protocol's success.

Trade Provisions

The Protocol restricts trade in controlled ODS with non-Parties to encourage universal participation. Parties ban import/export of controlled substances from/to non-Parties.

Monitoring & Reporting

Parties report annually on ODS production, import, and export. Scientific, Environmental, and Technology & Economic Assessment Panels (TEAP) provide regular assessments.

Adjustments & Amendments

A dynamic instrument, the Protocol can be adjusted (accelerate phase-outs, binding) or amended (add new substances, requires ratification). Key amendments: London, Copenhagen, Vienna, Montreal, Beijing, Kigali.

Non-Compliance Procedure

An Implementation Committee reviews non-compliance, recommending facilitative measures to bring Parties back into compliance.

Focus on Ozone Depleting Substances (ODS)

Chlorofluorocarbons (CFCs)

E.g., CFC-11, CFC-12. Used as refrigerants, aerosol propellants, solvents, foam-blowing agents. Largely phased out globally.

Halons

Used in fire extinguishers. Very high Ozone Depletion Potential (ODP). Largely phased out.

Carbon Tetrachloride (CTC)

Used as a solvent and in production of CFCs. Phased out.

Methyl Chloroform

(1,1,1-Trichloroethane): Used as a solvent. Phased out.

Hydrochlorofluorocarbons (HCFCs)

Transitional substitutes for CFCs, lower ODP but still ODS and potent GHGs. Being phased out.

Methyl Bromide

Fumigant for pest control. Phased out for most uses; QPS uses allowed.

The Kigali Amendment: Addressing HFCs

Symbolic image of Kigali, Rwanda or an international conference

Key Dates

Adopted: October 2016 (Kigali, Rwanda)
Entered into force: January 1, 2019

Background & Objective

Hydrofluorocarbons (HFCs) were alternatives to CFCs/HCFCs, not depleting ozone. However, HFCs are potent greenhouse gases (GHGs) with high Global Warming Potentials (GWPs), contributing to climate change.

The Kigali Amendment aims to phase down the production and consumption of HFCs globally.

Mechanism

  • Adds HFCs to the list of controlled substances (New Annex F).
  • Establishes specific HFC phase-down schedules for different country groups.
  • Aims for an 80-85% reduction in HFC consumption by the late 2040s.
  • Expected to avoid up to 0.4°C of global warming by 2100.

India and the Kigali Amendment

India ratified the Kigali Amendment in September 2021.

India's phase-down schedule (later group):

  • Baseline: Average HFC consumption in 2024-2026.
  • Freeze Date: 2028.
  • First reduction: 10% below baseline by 2032.
  • Ultimate reduction: 85% below baseline by 2047.

India has developed a national strategy for HFC phase-down.

A Journey of Milestones

1987

Montreal Protocol Adopted

Signed in Montreal, Canada, on September 16.

1989

Entry into Force

The Protocol officially becomes international law on January 1.

1991

Multilateral Fund Established

To assist developing countries in meeting their obligations.

1992

India Becomes a Party

India joins the Montreal Protocol in June.

1990-1999

Key Amendments

London (1990), Copenhagen (1992), Vienna (1995), Montreal (1997), Beijing (1999) strengthen the Protocol.

2016

Kigali Amendment Adopted

Addresses HFCs to mitigate climate change, adopted in Kigali, Rwanda.

2021

India Ratifies Kigali Amendment

India formally agrees to the HFC phase-down commitments in September.

Triumphs of the Protocol

Ozone Layer Protection

Dramatic reduction (over 98-99%) in global production and consumption of major ODS.

Ozone Layer Recovery

Scientific assessments show the ozone layer is healing; Antarctic ozone hole showing signs of recovery.

Avoided Health Impacts

Prevented millions of cases of skin cancer, cataracts, and immune system suppression.

Climate Co-benefits

Phase-out of ODS (many are GHGs) significantly mitigated climate change. Kigali Amendment targets HFCs (GHGs).

Model for Cooperation

Demonstrates effective global environmental problem-solving through science, CBDR, financial aid, and adaptive management.

Stimulated Innovation

Led to development and adoption of ODS-free technologies and alternative substances.

Ongoing Challenges & Future Outlook

Illegal Trade & Smuggling

Some illicit trade in phased-out ODS still occurs, requiring vigilance.

Management of ODS Banks

Large quantities of ODS in existing equipment (e.g., old refrigerators, ACs) need proper management and destruction to prevent leaks.

HCFC Phase-out Completion

Completing HCFC phase-out, especially in developing countries, needs continued effort and support.

HFC Phase-down (Kigali)

Implementing HFC phase-down presents challenges for energy-efficient, climate-friendly alternatives in RAC sector, especially with growing demand.

Unexpected Emissions

Occasional reports of unexpected ODS emissions (e.g., CFC-11) require monitoring and enforcement.

Interaction with Climate Change

Climate change itself can affect ozone recovery. Some ODS alternatives might have other environmental concerns (e.g., TFA from HFOs).

Relevance for Competitive Exams (UPSC)

Prelims Focus Areas

  • Vienna Convention (framework, year)
  • Montreal Protocol (objective, year, ODS focus)
  • Ozone layer (importance, depletion causes)
  • Key ODS (CFCs, Halons, HCFCs, HFCs) & ODP concept
  • Multilateral Fund
  • Kigali Amendment (HFCs, climate co-benefit, India's role)
  • World Ozone Day

Mains (GS Paper III) Insights

Highly probable questions:

  • Success of Montreal Protocol as an international treaty and lessons for other global challenges (e.g., climate change).
  • Ozone layer depletion: causes, impacts, provisions of Montreal Protocol & Kigali Amendment.
  • India's role in Montreal Protocol and its HFC phase-down strategy.

Related Previous Year Questions (PYQs)

"Consider the following statements: Chlorofluorocarbons, known as ozone-depleting substances, are used

  1. in the production of plastic foams
  2. in the production of tubeless tyres
  3. in cleaning certain electronic components
  4. as pressurizing agents in aerosol cans

Which of the statements given above is/are correct?"

Answer: (c) 1, 3 and 4 only (Not typically used in tubeless tyre production).

"The formation of ozone hole in the Antarctic region has been a cause of concern. What could be the reason for the formation of this hole?"

Answer: (b) Presence of prominent polar front and stratospheric clouds; and inflow of chlorofluorocarbons (Polar stratospheric clouds - PSCs - play a key role).

"The 'Kigali Amendment' to the Montreal Protocol is related to:"

Answer: Phasing down Hydrofluorocarbons (HFCs).