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The Ozone Layer is a stratospheric shield of ozone in the stratosphere that protects humans and the environment from harmful levels of ultraviolet radiation from the sun.
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.
In 2014 it was set out that HCFCs would hopefully be completely phased out in developed countries by 2030 and developing countries by 2040.
What did the Montreal Protocol do?
The Montreal Protocol set out plans to regulate the production and consumption of ODS.
ODS (ozone-depleting substances) are man-made chemicals that damage the ozone layer when released into the atmosphere.
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.
Free radicals are unstable atoms (i.e. without a full outer shell of electrons). They react quickly with other atoms. In humans, they can damage cells, causing illness and ageing.
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.
How are CFCs destroyed to prevent them from being released into the atmosphere?
- Products containing CFCs (such as old refrigerators) are taken to disassembly facilities.
- Refrigerants are extracted from the compressor and aggregated with other CFCs.
- Contaminants (such as water and oil) are removed from the aggregate. The CFCs then undergo chemical analysis.
- Finally, CFCs are sent to a waste management facility and destroyed using high-temperature incineration.
- Destroying ODS generates carbon credits for reducing emissions, providing an incentive for nations.
- Since the 1st January 2000 law has banned CFCs from all new refrigerators and freezers.
- Fridge manufacturers across the European Union must accept returned fridges and dispose of them safely.
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 (hydrofluorocarbons) are similar chemicals to CFCs but lack chlorine atoms. Thus, they do not produce free radicals that damage the ozone layer.
HFC-134a was the primary recommended alternative to the CFC-12 refrigerant.
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.
Montreal Protocol - Key takeaways
- The Montreal Protocol was signed in September 1987 by all 198 member states of the United Nations.
- The Montreal Protocol was created to regulate the consumption and production of ozone-depleting substances (ODS) such as CFCs.
- Without the Protocol, ozone depletion would have reached a dangerous level, severely affecting life on Earth.
- The Montreal Protocol is considered highly successful. 99% of ODS were eliminated from the atmosphere, reducing ozone depletion.
- A major drawback of the Protocol was the recommendation to replace CFCs with HFCs. These were later found to be potent greenhouse gases.
- To rectify this, the Kigali Amendment was created to phase out the use of HFCs.
- In 2005, the Kyoto Protocol was created to limit carbon emissions from developed nations. This treaty is not considered as successful as the Montreal Protocol.
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
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