The Best Climate Agreement Was the Treaty to Protect the Ozone Layer

January 28, 2022
Est. Reading: 4 minutes

Lasting Lessons Include the Benefits of Flexibility and a Culture of Cooperation

montreal protocol meeting in october 2016
The 28th Meeting of the Parties to the Montreal Protocol in October 2016 where the Kigali Amendment to reduce emissions of HFCs was adopted. Photo credit: IISD/ENB

The 1987 Montreal Protocol on Substances that Deplete the Ozone Layer is justifiably celebrated as the basis for the near universal adoption of measures to phase out ozone-depleting chemicals. While not emphasized at the time, the chemicals eliminated were also potent greenhouse gases and would have contributed significantly to climate change. A treaty initially signed by a limited number of developed countries with the aim of a 50 percent reduction in a small set of chemicals was repeatedly amended. The list of chemicals restricted was expanded and the timetable for reductions accelerated. Developed countries also agreed to provide financial and technical assistance to enable participation by developing countries. In 2003, then United Nations Secretary-General Kofi Annan called it “perhaps the single most successful international environmental agreement to date.” Yet in the almost 20 years since, the Protocol has proven to be far more beneficial than originally predicted and has continued to evolve in ways that have made it dramatically more successful — with the potential to offer even greater benefits in the years to come.

­The Benefits of the Protocol Have Proven to be Greater Than Predicted

EPA prepared a multi-volume, peer-reviewed, 1600-page risk assessment in 1986. The conclusion was that without the Protocol the U.S. would incur an additional 40 million skin cancers, 12 million cataract cases, and 800,000 deaths among people then alive and born by 2075. The noted legal scholar Cass Sunstein argued that this analysis was largely responsible for the enthusiastic support of the U.S. for the Protocol. In contrast, Sunstein argued, the costs and benefits of a climate agreement were not as demonstrable, or at least not as quantifiable — even though EPA had produced a lengthy report outlining the likely warming and qualitatively describing the devastating impacts in 1983.

Sunstein qualified his analysis by noting EPA may have overstated the benefits of avoided UV-B radiation to support regulation. However, recent analysis shows the avoided dangers were in fact enormously greater. A panel of scientists and public health experts concluded that, as strengthened by amendments, the Protocol will have prevented 443 million cases of skin cancer, 63 million cases of cataracts, and 2.3 million deaths avoided by 2100.

The updated risk assessment shows uncertainty cuts both ways. Consistent with the limited understanding of ozone depletion at the time — the issue was only first theorized a decade earlier — some benefits of eliminating ozone-depleting chemicals were only identified much later. Scientific analysis published last year concluded that the increase in ultraviolet radiation avoided by the Protocol would have reduced vegetation resulting in an increase in atmospheric carbon sufficient to raise temperatures 0.5 to 1.0 °C. Recent analyses also document past failures to properly account for the economic benefits of carbon-reducing energy efficiency improvements.

Lesson: When there are dangers of great magnitude with consequences likely to be irreversible, there is a strong case for erring on the side of caution — what legal scholars call the “precautionary principle”.

Amendments to the Protocol Have Made It Still More Impactful

The Protocol has been described as a “start and strengthen” treaty, with the flexibility for adjustments through amendments as scientific understanding and technological capability evolved. Five amendments (adding new controlled substances) and six adjustments (accelerating controlled substance phase-out) have significantly increased the ambition and scope of the Protocol. The latter allows changes without the requirement for ratification and takes effect within six months of agreement (except for parties that affirmatively opt-out). Decisions are also made in cooperation with affected industries, creating incentives for participation and risks for laggards. These elements provide a model for other possible environmental initiatives, e.g., an international agreement to reduce methane.

In 2007, the Parties unanimously agreed to an adjustment to accelerate the phaseout of HCFCs, potent greenhouse gases as well as sources of ozone depletion. Use of HCFCs had been growing due to perverse incentives created by carbon reduction credits available for reducing another chemical associated with the production of the HCFCs; the credits were highly valuable such that producing the HCFCs was highly profitable. The decision made specific reference to the need for countries to select substitutes that minimize impacts on climate, and estimates were the emissions avoided would delay warming by up to 1.5 years.

An even more significant climate policy, the Kigali Amendment, was adopted in 2016 to dramatically reduce HFCs, greenhouse gases up to 15,000 times as potent as CO2, and widely used for air conditioning and refrigeration. Ironically, the chemicals were introduced as substitutes for ozone-depleting compounds. Rising temperatures have contributed to rapid growth in demand for air conditioning and refrigeration, in turn increasing demand for electricity resulting in more carbon emissions. Phasing out the HFCs could avoid up to 0.5 °C warming, with an equivalent saving through improvements in the energy efficiency of cooling equipment. In a rare bipartisan act, in December 2020, Congress approved the American Innovation and Manufacturing Act including provisions to implement the requirements of the Kigali Amendment in the U.S. Notably the legislation was supported by the affected industries. The Protocol has thus repeatedly brought about significant reductions in greenhouse gas emissions — without the media attention or thousands of observers attending climate negotiations.

Lesson: A flexible design and culture of cooperation greatly increases the chances for successful treaty outcomes.

The MP can be the basis for still more environmental benefits

Scientific and technical experts continue to find opportunities for using the Montreal Protocol to reduce additional greenhouse gas emissions and other sources of environmental degradation. A recent example is a proposal to narrow the feedstock exemptions, originally included on the assumption the associated emissions were insignificant. Recent analysis has concluded that eliminating the exemption would provide substantial benefits, including reduced ozone depletion, climate warming, and plastics pollution, as well as safer conditions for chemical workers and surrounding communities. This new understanding of linkages between HFC feedstocks and plastics manufacturing provides yet another opportunity for the parties to further strengthen the Montreal Protocol to better protect the environment and human health, consistent with the “start and strengthen” philosophy of the agreement.

Lesson: Once a culture of cooperation and a process for continued progress is created, there are no end to the benefits that result.

Alan Miller is a former climate change officer in the International Finance Corporation (2003–13) and climate change team leader, Global Environment Facility (1997–2003)

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