Montreal Protocol

Way back in the 1970s, two chemists began studying the impact of certain molecules in the Earth's atmosphere. They found that these molecules might be the cause of Ozone breakdown. Ozone (O₃) is a highly oxidising molecule. At ground level, ozone is a respiratory hazard. But thousands of metres above the Earth, in the stratosphere, it keeps everyone safe. These scientists paved the way for us to gain understanding and ultimately protect the ozone layer.

The Montreal Protocol: Definition

On 15th September 1987, the Montreal Protocol on Substances that Deplete the Ozone Layer was signed. This groundbreaking global treaty was the first to address an environmental problem that was still theoretical. Furthermore, it is the only UN treaty to date that has been ratified by all 198 member states.

What did the Montreal Protocol do?

The Montreal Protocol set out plans to regulate the production and consumption of ODS.

The treaty phased out ODS consumption and production in a step-wise manner.

All parties had specific responsibilities, including:

• control of ODS trade
• annual data reporting
• national licencing systems
• binding, time-targeted, measurable commitments.

All nations had equal responsibilities, but the timeline of change was based on their level of development.

Why did we need the Montreal Protocol?

In the early 1970s, a scientists realised that anthropogenic emissions of CFCs could damage the ozone layer.

What are CFCs?

CFCs (chlorofluorocarbons) are non-flammable, non-toxic chemicals. These non-harmful properties meant that they were commonly used as refrigerants, aerosol propellants and solvents.

However, once in the stratosphere, they can cause problems. The carbon-chlorine bonds break apart, creating chlorine free radicals that destroy ozone. Once released, these substances stay in the atmosphere for many years.

What would have happened without the Montreal Protocol?

Without the work of Paul Crutzen and the Montreal Protocol, the ozone layer would likely have been destroyed, providing no protection from the sun's ultraviolet rays. This could destroy the environment - killing marine life and plants. Without crops, humans would have suffered famines, as well as diseases such as cataracts, skin cancer and immune system problems.

Successes of the Montreal Protocol

The Montreal Protocol is considered highly successful. Without the Protocol, the ozone layer would be much more depleted than it is today.

• Over 99% of ODS have been eliminated from the atmosphere. Chlorine and bromine levels have also decreased.
• As a result, the ozone layer is beginning to recover. It is expected to return to pre-1980s levels by around 2050.

• The infamous Antarctic ozone hole is expected to recover by the 2060s. In 2019, the hole was the smallest it had been since recording started in the 1980s.
• If the protocol hadn't been put into place, ozone depletion would have continued, with holes forming over both Antarctica and the Arctic. Ultraviolet radiation would have been at a formidable level, likely leaving Earth uninhabitable.

The Montreal Protocol established the conversion to affordable, available substitutes for ODS.

Failures of the Montreal Protocol

Describing this treaty as a failure is difficult - but it was not without drawbacks.

Some criticised the treaty for bowing too much to industry influence. Others pointed out that the phasing-out of ODS led to a thriving black market and uncertainties in phaseouts of developing countries.

However, the most obvious drawback is encouraging the production of HFCs as an alternative product to CFCs.

HFCs were later discovered to be potent greenhouse gases.

The Montreal Protocol: Kigali Amendment

On 15th October 2016, 197 countries signed the Kigali Amendment under the Montreal Protocol.

This amendment committed to cutting down on the production and consumption of HFCs by over 80% in the following 30 years - equivalent to 80 billion tons of CO₂. Developed countries will reduce HFC consumption at the start of 2019. Most developing countries will end consumption in 2024, with a small number ending in 2028. Financing is provided to certain countries to help them transition to climate-friendly alternatives. The Kigali Amendment promoted enforcement, accountability and broad participation.

The Kyoto Protocol and the Montreal Protocol

The Kyoto Protocol was adopted on 11th December 1997 - but due to a complex ratification process, it didn't enter into force until 16th February 2005. 192 parties signed the treaty - less than the Montreal Protocol.

The Kyoto Protocol set binding emission reduction targets for industrialised countries, economies in transition, and the European Union.

These targets required:

• Registry and compliance systems
• Reporting, adaptation and an adaptation log

These targets add up to an average 5% emission reduction compared to 1990 levels.

Was the Kyoto Protocol a success?

The Montreal Protocol is considered much more successful than the Kyoto Protocol.

Why is this?

• The Kyoto Protocol only made modest steps to stabilise greenhouse gas emissions.
• It has been suggested that this is partly due to the actions of the US.
• Their domestic cost-benefit analysis didn't support the Protocol - it wouldn't have been justified even if all other parties complied.
• Generally, international agreements are unlikely to be effective unless the US believes it has more to gain than to lose.
• The US and China would have to bear the greatest cost of emission reductions. Persuasion is difficult because they are projected to lose relatively less from climate change.

Hopefully you are now more aware of the Montreal Protocol, CFCs and HCFs as well as other protocols that have come into play since.

^{1. American Carbon Registry, Destruction of Ozone Depleting Substances, 2022}

^{2. Cass Sunstein, Montreal versus Kyoto: A Tale of Two Protocols, University of Chicago Law School, 2006}

^{3. Debra Wilson, How do free radicals affect the body?, 2017}

^{4. Elizabeth DeSombre, The Experience of the Montreal Protocol: Particularly Remarkable, and Remarkably Particular, UCLA Journal of Environmental Law and Policy, 2000}

^{5. Frederike Albrecht, Healing the Ozone Layer, 2019}

^{6. Guus Velders, The importance of the Montreal Protocol in protecting climate, Environmental Sciences, 2007}

^{7. Jim Clark, Uses of Halogenalkanes, 2015}

^{8. Jos Lelieveld, Paul J. Crutzen (1933-2021), 2021}

^{9. Lindsay Maizland, Global Climate Agreements: Successes and Failures, 2021}

^{10. Lizzy Rosenberg, Here’s What Will Happen to Life on Earth, if the Ozone Layer Fully Depletes, 2021}

^{11. Professor Thomas Peter, The Montreal Protocol at 30: what has it achieved?, 2017}

^{12. United Nations Climate Change, What is the Kyoto Protocol?, 2022}

^{13. United Nations Environment Programme, About Montreal Protocol, 2022}

^{14. United States Environmental Protection Agency, Recent International Developments under the Montreal Protocol, 2021}