A treaty that actually works on climate change

Duncan Brack on how the Montreal treaty to protect the ozone layer turned into a powerful tool to fight global warming

Celebrations at the signing of the Kigali amendment that aims to curb the use of hydrofluorocarbons

At 7am on Saturday October 15, 2016, in the Rwandan capital Kigali delegates to the Twenty-Eighth Meeting of the Parties to the Montreal Protocol burst into applause. News reports and commentators later that day were enthusiastic. ‘Kigali deal on HFCs is big step in fighting climate change’, declared the Guardian; ‘Kigali delivers second big climate deal’ announced the Indian Express; ‘October 15, 2016: the day the Earth got a little cooler’ tweeted the US Environmental Protection Agency.

What happened in Kigali? Why so much joy over an amendment to a 29-year-old treaty which took seven years to agree? And how come an agreement designed to protect the ozone layer was being used to fight climate change?

The 1987 Montreal Protocol on Ozone-Depleting Substances has a good case for being regarded as the world’s most successful environmental treaty; indeed, as UN Secretary-General Kofi Annan put it in 2003, possibly even the single most successful international agreement of any kind. Its aim was to phase out the production and consumption of the chemicals that scientists had discovered were destroying the Earth’s stratospheric ozone layer, which absorbs much of the harmful ultraviolet-B radiation from the Sun.

By the mid-80s it was becoming evident that chlorofluorocarbons (CFCs), widely used in aerosol sprays, as coolants for refrigeration and air-conditioning, as blowing agents for foams and as solvents, and halons, used as fire suppressants, when released into the atmosphere helped to destroy ozone molecules in the stratosphere. The result was a deepening ‘hole’ in the ozone layer over polar regions and a fall in its thickness over mid-latitudes. The impacts on human, animal and plant life – including, in humans, cataracts, skin cancer and a weakening of the immune system – were potentially severe.

Over the next 25 years actions taken by the parties to the Montreal Protocol – which by 2009, included every country in the United Nations – phased out more than 98 per cent of the consumption of all ozone-depleting chemicals. There is a significant lag before full recovery of the ozone layer, but there are already early signs that depletion is stopping.

Many factors contributed to this achievement: the design of the protocol, which allowed for procedures to add new categories of chemicals and accelerate phase-out in the light of new scientific knowledge; the special treatment afforded to developing countries, which enjoyed longer phase-out schedules and financial assistance; an effective non-compliance mechanism, employing the threat of trade measures against parties who failed to comply and non-parties; the participation of scientists and industry technical experts; and pressure from NGOs, particularly in the early days, to speed up phase-out.

Perhaps most importantly, once industry understood that the markets for ozone-depleting chemicals would close permanently, they proved much faster than predicted at developing replacements that were less harmful to the ozone layer. Production of the chemicals was concentrated among a relatively small number of companies and countries, making the issue much less difficult to address than the far broader problems of climate change. (In fact, since most ozone-depleting chemicals are also powerful greenhouse gases, the Montreal Protocol has contributed more to slowing down global warming than the 1997 Kyoto Protocol on controlling greenhouse gases.)

But in solving one problem, the Montreal Protocol made another worse. In phasing out CFCs and other ozone-depleting chemicals, industry turned increasingly to hydrofluorocarbons (HFCs) to substitute for them in refrigeration and air-conditioning, foams and solvents. Unlike CFCs, HFCs do not deplete the ozone layer, but they are very powerful greenhouse gases – up to thousands of times more damaging to the climate than carbon dioxide. With consumption expanding at a rate of 10-15 per cent per year, the impact on the climate is a projected 0.1C of global average temperature rise by mid-century, increasing by up to 0.5C by 2100.

This was the background to the attempts, starting in 2009, to amend the Montreal Protocol to add HFCs. The proposal for an amendment was not new – the Protocol had already been amended on four occasions – but it was unprecedented to propose to add non-ozone-depleting chemicals to the treaty. The amendment’s proponents found a justification in the text of the Vienna Convention (the protocol’s parent treaty) but more convincing was the argument that since this was a problem that the Montreal Protocol had created, its parties had a moral duty to solve it.

Since HFCs are used in precisely the same applications as CFCs, the policy framework and institutions of the Montreal Protocol were well placed to deal with them. And given that substitutes existed for many (though not all) uses of HFCs, the consumption-and-production-phase-out model of the Montreal Protocol was better suited than was the emissions control regime of the UN Framework Convention on Climate Change and Kyoto Protocol.

These arguments were to be rehearsed in weary detail over seven years. While support for an amendment on HFCs steadily grew, there was also determined opposition from some developing countries, which were only just starting to phase out the last category of ozone-depleting chemicals (hydrochlorofluorocarbons, HCFCs) and were wary of undertaking another potentially costly commitment.

Some of the bigger ones, particularly China and India, did not wish to restrain their growing export markets − China is the world’s largest exporter of refrigerators. There were also doubts about some of the replacements for HFCs, sometimes because of their flammability (hydrocarbons) or toxicity (ammonia) but also because many of them do not work so effectively in the high temperatures found in many Middle Eastern and Asian countries.

Their opposition was gradually chipped away by further technological developments, as alternatives to HFCs became more readily available – and the expectation that, as with CFCs, industrial innovation would accelerate once agreement had been reached. The increasing willingness of developed countries to commit to additional financial support was also a factor, as was the spread of national regulations controlling HFCs in the EU and other developed countries, which promised steadily to close off their markets.

Just as important was years of patient diplomacy, in particular by the United States with Brazil, China and India, which were all originally opponents of an amendment. The successful conclusion of the Paris Agreement on climate change in December 2015 also had an impact. Under the Kigali Amendment HFCs will be added to the list of controlled chemicals under the Montreal Protocol. Developed countries are to start their phase-down in 2019, ending with an 85 per cent reduction by 2036.

Developing countries are split into two groups. The first − most of them − will freeze consumption by 2024, and start to phase down in 2029, ending with an 80 per cent reduction by 2045. The second group − India, Iran, Iraq, Pakistan and the Gulf countries − will meet a later deadline, with a freeze in 2028 and consumption reductions starting in 2032, ending with an 85 per cent reduction in 2047. There are also exemptions for some uses in hot countries.

Although some NGOs criticized the Kigali Amendment for its lack of ambition, particularly in the long phase-down schedules it allowed to some developing countries, experience suggests that the control schedules are very likely to be accelerated as technology advances. Almost every category of chemicals controlled by the Montreal Protocol has seen this happen, and there is no reason to think that industrial innovation, once pointed in the right direction, cannot achieve this once again.