Montreal Protocol and Its Amendments

The Montreal Protocol on Substances that Deplete the Ozone Layer is an international environmental treaty agreed upon in 1987. It operates under the 1985 Vienna Convention for the Protection of the Ozone Layer. The treaty establishes legally binding schedules to phase out the production and consumption of ozone-depleting substances, including chlorofluorocarbons, halons, and hydrochlorofluorocarbons, protecting the stratospheric ozone layer.

Structure and Key Mechanisms

The treaty categorizes controlled chemicals into distinct groups based on their chemical structure and Ozone Depletion Potential (ODP).

Core Operational Principles

• The protocol sets different phase-out schedules for developed countries (non-Article 5 parties) and developing countries (Article 5 parties).
• Article 5 parties receive a ten-year grace period to meet baseline control targets.
• Trade restrictions bar parties from trading controlled substances with non-parties to prevent production leakage.
• The treaty mandates periodic assessments conducted by the Scientific, Environmental Effects, and Technology and Economic Assessment Panels.

The Multilateral Fund

• Established in 1991 under Article 10 of the protocol to assist developing nations in meeting compliance targets.
• The fund provides financial assistance, technical cooperation, and technology transfer.
• Four international bodies act as implementing agencies: the United Nations Development Programme (UNDP), the United Nations Environment Programme (UNEP), the United Nations Industrial Development Organization (UNIDO), and the World Bank.

Controlled Substances and Phasing Mechanisms

Ozone-depleting substances contain chlorine or bromine atoms that destroy stratospheric ozone through catalytic reaction cycles.

Chronology of Amendments and Adjustments

The Montreal Protocol has undergone five formal amendments to accelerate phase-out dates and expand the list of controlled substances.

Major Amendments to the Protocol

• London Amendment (1990): Added ten new CFCs, carbon tetrachloride, and methyl chloroform to the control list. It formally established the Multilateral Fund.
• Copenhagen Amendment (1992): Added hydrochlorofluorocarbons (HCFCs), hydrobromofluorocarbons (HBFCs), and methyl bromide. It advanced the phase-out deadline for CFCs to 1996 for developed nations.
• Montreal Amendment (1997): Mandated a worldwide licensing system for the import and export of ozone-depleting substances to curb illegal trade.
• Beijing Amendment (1999): Added bromochloromethane (CH_2BrCl) to the list of controlled substances and imposed trade controls on HCFCs.
• Kigali Amendment (2016): Brought hydrofluorocarbons (HFCs) under the control regime to curb global warming potential, entering into force on January 1, 2019.

The Kigali Amendment and HFC Phase-Down

Hydrofluorocarbons do not deplete the ozone layer because they lack chlorine and bromine. They are powerful greenhouse gases with high Global Warming Potential (GWP).

Division of Parties Under the Kigali Amendment

The Kigali Amendment divides member countries into three groups with different baseline years and phase-down targets.

India’s Compliance and Implementation

India became a party to the Vienna Convention in 1991 and ratified the Montreal Protocol in June 1992.

Institutional Framework and Domestic Milestones

• The Ozone Cell within the Ministry of Environment, Forest and Climate Change (MoEFCC) acts as the national nodal body for protocol implementation.
• The Ozone Depleting Substances (Regulation and Control) Rules, 2000 regulate the production, trade, and use of controlled chemicals.
• India phased out CFCs, carbon tetrachloride, and halons on August 1, 2008, 17 months ahead of the Montreal Protocol schedule.
• The India Cooling Action Plan (ICAP), launched in March 2019, provides a 20-year roadmap to reduce cooling demand by 20% to 25% and refrigerant demand by 25% to 30% by 2037–38.
• India ratified the Kigali Amendment in September 2021 and prepared a national strategy for phasing down HFCs starting in 2028.

Important Facts

• The Montreal Protocol was opened for signature on September 16, 1987, and entered into force on January 1, 1989.
• September 16 is observed annually as World Ozone Day (International Day for the Preservation of the Ozone Layer).
• The Vienna Convention and the Montreal Protocol are the first treaties in the history of the United Nations to achieve universal ratification across 198 member states.
• Chlorofluorocarbons release active chlorine radicals under ultraviolet radiation, with a single chlorine atom capable of breaking down over 100,000 ozone molecules.
• Ozone thickness is measured in Dobson Units (DU), where one Dobson Unit equals a 0.01 mm layer of pure ozone at standard temperature and pressure.
• An ozone hole is defined when atmospheric ozone concentration drops below 220 Dobson Units over Antarctica.
• Mario Molina, F. Sherwood Rowland, and Paul Crutzen received the 1995 Nobel Prize in Chemistry for identifying the chemical mechanisms of ozone depletion.
• Hydrofluoroolefins (HFOs) and natural refrigerants like isobutane (R-600a), propane (R-290), and carbon dioxide (R-744) are low-GWP alternatives replacing HFCs.
• The Multilateral Fund operates under an Executive Committee comprising seven developed and seven developing nations serving one-year terms.
• Complete global compliance with the Kigali Amendment aims to avoid up to 0.5°C of global warming by 2100.
• Scientific assessments project that the Antarctic ozone layer will recover to 1980 baseline levels around 2066, while the global ozone layer is expected to recover around 2040.