Montreal Protocol

• DATE: Signed September 16, 1987; took effect January 1, 1989; amended 1990, 1992, 1995, 1997, 1999, 2007, 2016, and 2018

The Montreal Protocol was created to help preserve the Earth’s ozone layer by severely limiting the production and use of chlorofluorocarbons (CFCs) and other halogenated compounds.

Background

The Montreal Protocol on substances that deplete the layer was signed in 1987 by forty-six nations, including the United States. It entered into force on January 1, 1989. The Montreal Protocol was designed to control the production and of chlorofluorocarbons (CFCs) and other halogenated compounds that were suspected of causing the destruction of the ozone layer. Industrialized countries, such as the United States, were committed to freezing consumption of certain CFCs at 1986 levels by mid-1989 and to reducing 1986 consumption levels by 20 percent by mid-1993. By mid-1988, a 50 percent reduction in 1986 consumption levels was required by the terms of the protocol. Halons (such as CF₂BrCl, CF₃Br, and C₂F₄Br₂) were to be frozen at 1986 consumption levels in 1992. By 2024, the Montreal Protocol had been signed by 197 nations and the European Union.

In 2019, the Kigali Amendment came into force. Countries that ratified the amendment were required to reduce their use of HFCs by more than 80 percent over the next 30 years. As of late 2024, 160 nations and the European Union had ratified the amendment.

Provisions

The Montreal Protocol is directed at protecting the ozone layer, a global 10 to 20 kilometers above the Earth’s surface that screens out most of the ultraviolet radiation emitted by the Sun. Ultraviolet light can lead to mutations and cancers in living things. Participating nations were motivated to act by four major scientific events: In 1974, the mechanism by which CFCs deplete ozone was demonstrated, which led the United States to ban CFCs in aerosols unilaterally in 1978; a “hole” in, or more correctly a thinning of, the ozone layer was discovered over Antarctica in the early 1980s; evidence linking the ozone hole to CFCs was provided in 1985; CFC substitutes were developed by important CFC producers such as the company DuPont.

The Montreal Protocol is one of the most successful environment protection agreements in the world. The protocol established a mandatory timetable for the phaseout of ozone-depleting substances.

Impact on Resource Use

The major innovation of the Montreal Protocol was the call for a gradual reduction in CFC production and the allowance for adjustments in the members’ activities based on updated scientific information. Thus, the amended protocol in 1990 accelerated reduction levels because new data suggested that the extent of ozone destruction was greater than anticipated. However, an immediate total ban of CFCs would have been unworkable, because CFCs were crucial in important cooling and air-conditioning applications. In addition, without reasonably inexpensive alternatives to CFC use in air-conditioning, the distribution of temperature-sensitive medical supplies such as blood, 75 percent of food shipments, and the habitability of many workplaces dependent on air-conditioning would have been affected.

There has been some disagreement on the extent and effect of ozone depletion. Substantial arguments arose among the signers of the Montreal Protocol regarding the level of production cuts required to amend the problem. Disagreements also existed regarding the level of support that developing nations were entitled to in their efforts to do without CFCs. For them, compliance meant forgoing the benefits of CFCs (particularly for refrigeration) that industrialized countries had enjoyed at crucial phases in their economic growth. Eventually, compensation of at least $350 million was set aside by industrialized countries to induce developing nations to eliminate their CFC production.

The Multilateral Fund for the Implementation of the Montreal Protocol provides funds to help developing countries phase out the use of ozone-depleting substances (ODS). ODS are used in refrigeration, foam extrusion, industrial cleaning, fire safety, and fumigation. The Multilateral Fund was the first financial mechanism to be created under an international treaty. It embodies the principle agreed upon at the 1992 United Nations Conference on Environment and Development (Earth Summit) that countries have a common but differentiated responsibility to protect and manage the global commons.

The fund is managed by the Humanitarian Affairs Executive Committee with an equal representation of seven industrialized and seven Article 5 countries, which are elected annually by a Meeting of the Parties. The committee, which reports annually to the Meeting of the Parties on its operations, was established by a decision of the Second Meeting of the Parties to the Montreal Protocol (London; June 1990) and began its operation in 1991. The main objective of the Multilateral Fund is to assist developing country parties whose annual per-capita consumption and production of ODS is less than 0.3 kilogram to comply with the control measures of the Montreal Protocol.

Contributions to the Multilateral Fund from the industrialized countries, or non-Article 5 countries, are assessed according to the UN scale of assessment. Since its establishment, the fund has been replenished many times and has supported more than 8,500 projects. In 2024, the Executive Committee approved 396 projects, granting a total of $175 million in funding. Of these projects, 84 contributed to the phasing down of HFCs. Another 168 contributed to the phasing out of HCFCs in developing nations.

Each country enacts the provisions of the Montreal Protocol in specific ways. For example, Australia has been a leading supporter of international efforts to protect the ozone layer since the early 1980s, when initial moves were made through the United Nations to limit the global release of ODS. As of March 2009, Australia had ratified all the amendments to the protocol, which include the Vienna Convention for the Protection of the Ozone Layer (1985) and the Montreal Protocol on Substances That Deplete the Ozone Layer (1987) and the following amendments to the protocol: London (1990), Copenhagen (1992), Vienna (1995), Montreal (1997 and 2007), Beijing (1999), Kigali (2016), and Quito (2018). Australia is a member of important decision-making bodies within the protocol framework, including the Implementation Committee, the Scientific Assessment Panel, and the Methyl Bromide Technical Options Committee. An active role in these areas allows Australia a degree of influence over the nature and direction of global ozone protection issues.

Although Australia accounts for less than 1 percent of global emissions of ODS, its participation in the protocol means that it meets international standards in full. For example, Australia implements its obligations under the Montreal Protocol through the Australian Ozone Protection and Synthetic Greenhouse Gas Management Act (1989), which states that all licenses to import or export ODS carry a condition that the licensee must import or export the substance only from or to a country that has ratified the Montreal Protocol and the relevant subsequent amendments. To help facilitate this, the appropriate government minister must maintain a Register of Montreal Protocol Countries and the substances for which those countries are to be treated as a Montreal Protocol country.

Australia met or exceeded all its phaseout obligations under the Montreal Protocol. For example, it essentially phased out consumption of HCFCs by 2016, four years ahead of the schedule required under the protocol. In doing so, Australia consumed 61 percent less HCFCs in the period to 2020 than required under the Protocol, even after the parties to the Montreal Protocol agreed in 2007 to advance HCFC phaseout globally.

Bibliography

Bankobeza, Gilbert M. Ozone Protection: The International Legal Regime. Utrecht, the Netherlands: Eleven International, 2005.

Glas, Joseph P. “Protecting the Ozone Layer: A Perspective from Industry.” In Technology and Environment, edited by Jesse Ausubel and Hedy E. Sladovich. Washington, D.C.: National Academy Press, 1989.

Hunter, David, James Salzman, and Durwood Zaelke. International Environmental Law and Policy. 3d ed. New York: Foundation Press, 2007.

"International Actions

Kaniaru, Donald, ed. The Montreal Protocol: Celebrating Twenty Years of Environmental Progress—Ozone Layer and Climate Protection. London: Cameron May, 2007.

Susskind, Lawrence E. Environmental Diplomacy: Negotiating More Effective Global Agreements. New York: Oxford University Press, 1994.

Zerefos, Christos, Georgios Contopoulos, and Gregory Skalkeas, eds. Twenty Years of Ozone Decline: Proceedings of the Symposium for the Twentieth Anniversary of the Montreal Protocol. Dordrecht, the Netherlands: Springer, 2009.