The Montreal Protocol is the poster child of environmental agreements. It is seen as a stunning success, as it reduced the substances in the atmosphere it was meant to manage by almost 100 %. Without it the ozone layer would be massively depleted by now and we would have seen a significant rise in skin cancer and eye damage globally. Also, many of the substances involved also contribute to climate change and it is estimated that the Montreal Protocol significantly contributed to slowing down global warming. It is also adopted by 197 countries, which includes every country that ever produced significant amounts of ozone depleting substances.

So, if there already is the perfect environmental agreement, why do we not simply copy it and solve climate change? In this post we will look first at why the Montreal Protocol was so successful and then explore why it is not straightforward to transfer its lessons to climate change.

The history of the Montreal Protocol

First, we have to understand what actually happened. For this I am relying on a retrospective paper by Albrecht & Parker (2019). In 1928 Chlorofluorocarbons (CFCs) were discovered. Over the following decades, they found widespread use, especially as refrigerants. Only in the 1970s scientists started to speculate if the CFCs remained in the upper atmosphere and that in combination with UV light they could release chlorine atoms, which could remove ozone in a catalytic reaction. This removal is a big problem, as ozone blocks our UV light from reaching the Earth’s surface. In humans such elevated UV levels can lead to skin cancer and eye damage.

Once this scientific hypothesis was stated, people started to take notice and individual countries like Norway started to phase out CFCs, because domestic politics and environmental concerns of the public pushed them to act. However, there was still a lot of reluctance, due to the scientific uncertainty of the processes involved. Only after the discovery of the ozone hole in 1985, things really started to get moving. The hole was much larger than what scientists had expected. This served as a dramatic, focussing event. This created a sense of urgency which helped to get the Montreal Protocol started.

The main actors

Creating an international agreement that is able to unite all countries behind it is very difficult. For every individual country it is advantageous to hope that the other countries will stop their production to save the ozone layer, but that the individual country itself just keeps on producing, getting both the benefit of having CFCs, while also having a (mostly) intact ozone layer. Up until the Montreal Protocol many economists believed that such a collective action problem could not be solved on an international scale. Also, ozone is especially hard for such a collective action problem, as it is important, but is invisible and the damages slowly accumulate.

You can identify different coalitions of actors from the discovery of the dangers of ozone until the Montreal Protocol was signed. At the beginning it was mostly a scientific endeavour, where individual scientists or small groups explored the topic and then over time saw themselves to be driven to more active roles in public discourse, pushing towards a solution to something they saw as a big problem. Over time, as the scientific evidence became more solid, the main push came more from international organizations like large NGOs, but also the United Nations Environmental Program. Also, a group of countries led by example. This included Canada, Finland, Norway, Sweden and the United States. They implemented regulations before a global compromise was found. Their main motivation was internal political pressure, as citizens in those countries were concerned about health risks and environmental problems and pushed for regulation. What also helped to get the Montreal Protocol implemented was that major producing companies were involved and after some deliberation decided to back the phase out. However, this change of heart only happened after substitutes were found. In particular, DuPont pushed for regulations because it was in a good market position to sell the substitutes once CFSs would be outlawed.

There were also actors who were opposed to regulation, like Japan, France, Italy, the UK or the Soviet Union, as they were major producers. Also, a larger bloc of developing countries were somewhat opposed, as they did not want to lose the chance to use CFCs in the future.

How it got implemented

The Montreal Protocol was the result of several precursor agreements. The most important one of these was the Vienna Convention. In it, there were not any commitments to reduce CFC usage, but instead it was meant to set up mechanisms for collaboration and for monitoring.These consisted mostly in the legislative and administrative layers that allowed data to be shared easily. Such processes could be discussed more easily, while there weren’t any commitments attached to it.

Negotiations got more difficult once the discussions around actually reducing emissions started. Some countries argued for cutting down production by a certain percentage, others thought it would be better to set a global limit, which cannot be overstepped or that there would be a ban on consumption, but not production. Also, there was much disagreement on how quickly and how ambitious the aims should be implemented.

A breakthrough was reached by a proposal by the United Nations Environmental Program. This proposal emphasized the focus on control measures, without demanding any commitments from the involved parties, but clearly laid out all the commitment options and emphasized that a decision is needed. This allowed the progress to pick up again and more than 50 countries plus industry and NGOs joined the new negotiations, convened and administered by the United Nations. This was combined with increasing public pressure to find a solution and resulted in the actual Montreal Protocol. While the initial commitments in the proposal were not super ambitious, the agreement included strict rules for monitoring and importantly, mechanisms to regularly meet again and revisit the aims in light of progress and new scientific evidence. These regular follow up meetings ensured success, as they gradually led to increasing ambitions.

The negotiations also resulted in a multilateral fund with financial transfers to developing countries, which motivated many of them to join.

Some key differences to climate change

As successful as the Montreal Protocol was, it differs in some fundamental ways from the current situation with climate change. Climate change is a much more complex problem. It is not about simply phasing out one group of industrial gas. Instead the discussion is about the fundamental energy production of society. Much more has to be changed. Also, the big industrial players are not supportive of phasing out fossil fuels. For the CFC producers, this was just one chemical among many. However, for fossil fuel companies, without fossil fuels, there is not really anything left and thus they resist change much more.

Problems of the Montreal Protocol

As good as the Montreal Protocol might have worked, it still has its problems. Two important ones I want to discuss here. The delayed phase out of methyl bromide (Gareau, 2015) and the recent problems around unexpectedly rising emissions of some chemical regulated under the Montreal Protocol (Solomon et al., 2020).

Phasing out methyl bromide

As mentioned above, one key feature of the Montreal Protocol was that it was meant to gradually increase the commitments. This not only meant that it was to sharpen the limits of existing chemicals, but also include more and more chemicals in the agreement, as it became clear that they were also harming the ozone layer. One of these substances was methyl bromide. Methyl bromide is really poisonous and was often used to sterilize soils and buildings.

It was also to be regulated via the Montreal Protocol and it ultimately was, but only with a very long delay. Up until methyl bromide had to be regulated, the main thing the Montreal Protocol was oriented around was the precautionary principle, meaning if there is reasonable certainty that a damage will occur at some point, it is better to act and prevent it. Methyl Bromide was different in its regulation, because it had powerful backers. Especially US farmers lobbied hard to delay, as they argued that methyl bromide was essential for their business. This changed the guidelines around when a substance should be outlawed. There had always been exceptions for substances that were essential for human society, and which had no good alternative. In the discussion around methyl bromide, the lobbyists managed to get this extended to everything where a prohibition would lead to “significant market disruption”.

This was so vague and wide, that it allowed them to push back the outlawing of methyl bromide by several years. Even before the phase out, research indicated that no actual market disruptions would happen, as it was relatively easy to replace and also only used in non-essential foods like strawberries. This was also how it played out.

Methyl bromide is a cautionary tale of what happens when profits of small interest groups are valued higher than the precautionary principle to prevent harms from society as a whole.

Rising emissions of harmful substances

Although the Montreal Protocol was really good in phasing out harmful substances in general, the tricky thing is that many of those substances are quite long lived, this means once you put them in the atmosphere, they can stay there for decades. Also, there are still a lot of harmful substances in things like old refrigerators. This produces a constant renewal, until all of those old devices have been discarded. Due to this and their general longevity, even a small producer can significantly contribute to global levels, given enough time. This is what happened around the mid 2010s. Until then the level of ozone depleting substances had been declining, but started to slowly creep up again for some substances. By 2020 much of this had been reined in again and levels were falling. But it shows that even a well thought out protocol has the problem of continuous challenges. As long as humans can produce ozone depleting substances, we will have to stand watch and make sure nobody does it.

Also, there is one big omission when it comes to ozone depleting substances: nitrous oxide. It is not regulated under the Montreal Protocol and it is continuously emitted from all kinds of processes. As long as it is continuous to be emitted, there will be some damage to the ozone layer. It is mostly emitted from agriculture, which has a strong lobby behind it (as we already saw with Methyl Bromide) and thus could avoid regulation.

Why is it so difficult to transfer the learnings from the Montreal Protocol to climate negotiations?

If the Montreal Protocol is so great, why don’t we use it more as a blueprint for future success? Some of the reasons we already mentioned here, like ozone being a much simpler problem than climate change, but there is more.

The limits of knowing things

Ungar (2000) makes the argument that the information gathering from ordinary citizens is very limited and so they can only understand simple scientific arguments. This is partly driven by only a minority of the population being interested in gathering information they do not directly need for their life, but also by the so-called knowledge-information paradox.

The available information about pretty much everything has exploded over the last decades. But each human only has a limited capacity to process information. Therefore, everybody has to be selective in the knowledge they consume. However, this also means that as the amount of available knowledge rises, but individual humans don’t scale, over time this means that everybody gets more ignorant automatically, as there is just so much you do not know. It also encourages you to specialize in a niche, so you have at least one thing you are knowledgeable about.

The tricky thing is though that to understand something new, you need to be able to attach it to some knowledge you already have. But if you are more specialized, and venture in a new field, you have nothing to latch onto and don’t understand anything. The same makes it harder for media to communicate findings, as they cannot really assume any prior knowledge by their audience. All this leads to society becoming isolated groups of experts, whose insights seem arcana to everyone else.

Also, not all knowledge is made the same. In an attention economy, those pieces of knowledge that are more virulent have a higher chance of being distributed. Other reasons for distributing information is it being immediately useful for daily life or something that might interest the people you talk to. None of these attributes are super common for scientific knowledge.

Therefore, a set of things have to come together for scientific knowledge to be of any interest for ordinary citizens. It has to be immediately useful for conversations or everyday life, attach to already existing knowledge and has a sense of urgency. All of those were true for the Ozone hole. The discovery of the ozone hole being way larger than anybody expected meant that it felt urgent. Also, knowing about it was immediately useful for everyday life. Other people were talking about it and so you could seem knowledgeable if you could chip in. Also, knowing about it meant you could limit your sun exposure. Finally, the idea of a hole in a kind of shield for Earth could easily attach to existing popular ideas like Star Trek or Star Wars where an energy shield protected from harmful rays. All this showed up in consumers voluntarily reducing their use of CFC containing products, while at the same time buying more UV protection.

None of these things are really true for climate change. It is just a much more complex phenomenon. Explaining the Greenhouse effect takes a bunch of minutes, does not easily attach to anything in popular culture and is just the starting point for a long explanation. Due to this it also does not feel urgent, especially as no single event a person experiences can easily be attributed to climate change. Finally, in the current societal atmosphere talking about climate change does not give you any street credibility.

The challenge of climate negotiations

The argument above explains why climate change negotiations seldom find massive popular support. But climate change negotiations have a variety of further problems that were easier to solve for the Montreal Protocol. This is explained in another retrospective paper by Barrett (2014).

The problem is not that we don’t know what we should be doing. Pretty much everybody agrees that staying below 2°C warming would be pretty good. We need collective action, but we are stuck in a dilemma. We all want the world to be saved, but everybody would prefer it if everybody else pays the bill. This could be a coordination game with two stable equilibria, in one each country stays in the safe zone and we are good and in the other, they all breeze past the tipping point into catastrophe. But for this to be true you would have to have a clear global emissions limit. This would solve this by creating a treaty where everybody gets assigned a certain emission budget, but only has to adhere to it if everybody joins. If the amount of allowable emissions is uncertain, each country is incentivized to just assume that the upper bound of the uncertainty is correct, but if everybody does this, you have a high likelihood that more emissions are spent than it would be safe. This means as long as uncertainty remains, the situation is more like a prisoner’s dilemma.

It still could be fixed with some kind of enforcement to make sure that everybody rather stays on the lower bounds of uncertainty, but here the problem is that if there is strict enforcement, then countries have an incentive again to not even join.

What the Montreal Protocol did well was that it had enforcement. Rather than building a club of countries that preferentially trade with each other, the protocol restricted trade in the controlled chemicals, and in products that contained or were made with them, between members and non-members. This meant you had a strong incentive to join and adhere to the plan, because otherwise you would be cut off from the chemicals you needed and your products would lose access to members’ markets. That incentive only grew once the main producing countries signed up, since non-members could then barely source the chemicals at all, so joining became less a choice than a necessity. This kind of mechanism is harder to apply to climate change, because fossil carbon is embodied in almost everything we trade, so there is no narrow class of goods you can restrict the way CFCs were.

Conclusion

None of the topics explored here really detract from the stunning success that the Montreal Protocol achieved. Still, it also has become clear that it was able to be successful by having a relatively straightforward problem. One group of chemicals, produced by a few countries and a few companies. There was some resistance, but it faltered as evidence continued to accumulate. When the science is clear and direct, it gets difficult to argue against it.

The move towards the Montreal protocol was slow at first, but then accelerated and finally saw a massive push once the ozone hole was discovered. Decades of ground work which then get pushed to the forefront by a dramatic event. Negotiations remained difficult (countries disagreed on cut percentages, consumption bans vs. production bans, timelines), but once the threshold passed, the agreement emerged within roughly two years.

This movement to save the ozone layer was driven by a wide coalition of actors in society. It started with scientists and some NGOs, but then a coalition of wealthy countries took up the problem and led by example, motivated by pressure from their own citizens. Even the major producing countries started to back things up, once they realized that change could not be avoided.

Overall, it seems that what worked was slowing building consensus or at least compromise which was then accelerated by a focusing event. But it only really came into force with good treaty design, which gave all countries a strong incentive to join and compensated countries that would mostly have a disadvantage for joining.

References

• Albrecht, F., & Parker, C. F. (2019). Healing the Ozone Layer: The Montreal Protocol and the Lessons and Limits of a Global Governance Success Story. In P. ’t Hart & M. Compton (Eds.), Great Policy Successes (p. 0). Oxford University Press. https://doi.org/10.1093/oso/9780198843719.003.0016
• Barrett, S. (2014). Why have climate negotiations proved so disappointing? Sustainable Humanity, Sustainable Nature: Our Responsibility, Extra Series 41.
• Gareau, B. J. (2015). Lessons from the Montreal Protocol delay in phasing out methyl bromide. Journal of Environmental Studies and Sciences, 5(2), 163–168. https://doi.org/10.1007/s13412-014-0212-x
• Solomon, S., Alcamo, J., & Ravishankara, A. R. (2020). Unfinished business after five decades of ozone-layer science and policy. Nature Communications, 11(1), 4272. https://doi.org/10.1038/s41467-020-18052-0
• Ungar, S. (2000). Knowledge, ignorance and the popular culture: Climate change versus the ozone hole. Public Understanding of Science, 9(3), 297–312. https://doi.org/10.1088/0963-6625/9/3/306