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Major Climate Win: Lessons for the Montreal Protocol

Two new papers published in Nature suggest that the CFC-11 emissions are back on a downward trajectory potentially avoiding substantial delays in the recovery of the ozone layer. The papers show an accelerated decline in global atmospheric concentrations of CFC-11 from 2018 to 2019, and attribute 60% of the decline to China. This is a huge win for the ozone layer and our climate, which would not have been possible without a concerted global response to the findings from the ground and the atmosphere.

In 2018 scientists found atmospheric CFC-11 concentrations had increased by about 25 percent from 2012-2016, despite nearly zero new production and consumption reported since 2006. The scale of this increase was enough to potentially delay ozone recovery by a decade and substantially contribute to global greenhouse gas emissions.

Evidence from the field: 2018 EIA Investigations

An EIA investigation released within weeks of publication of the atmospheric science revealed widespread illegal use of CFC-11 in China. Our initial findings, published in Blowing it: Illegal Production and Use of CFC-11 in China’s Foam Blowing Industry, exposed eighteen companies that reported illegal use of the banned substance, specifically as a blowing agent in producing polyurethane (PU) foams. Company representatives confirmed rampant use of CFC-11 in China’s PU foam insulation sector, in particular in the building and construction subsector.

Our subsequent report, Tip of the Iceberg: Implications of Illegal CFC Production and Use, provided hard evidence of CFC-11 by lab-testing foam samples gathered during our investigations and outlined unanswered questions regarding the potential extent of this environmental crime raising banks as a massive unaddressed issue. We called for a comprehensive review of the monitoring and enforcement regime of the Montreal Protocol and urged Parties to ensure robust domestic laws and enforcement.

Actions by China

Our evidence from the field was followed by a clampdown of the illegal use of CFC-11 in China, which appears to have played the critical role resulting in this now demonstrated downward trend. In 2018 and 2019, Ministry of Ecology and Environment (MEE) China carried out law enforcement inspections nationwide in addition to undertaking industry-wide responses. From June to August 2019, MEE conducted inspections in 11 key provinces, including Shandong, Hebei and Henan reporting inspection of 656 related enterprises, demolition of an illegal CFC-11 production site and finding 16 enterprises using CFC-11 illegally. MEE also reported sending supervisory working groups to all 16 carbon tetrachloride (CTC) enterprises to carry out on-site inspection and installing CTC production monitoring systems to monitor production processes and product flow in real time. China also announced establishment of six new laboratories capable of testing for ODS in insulation foam. The lessons from this crackdown have influenced China’s newly proposed regulation that covers Ozone Depleting Substances (ODS) and their substitutes, including hydrofluorocarbons (HFCs), which implements stronger fines and punishment for violations.

Actions by the Montreal Protocol

Just months after unexpected high emissions of CFC-11 were revealed, the Parties to the Montreal Protocol unanimously responded at their mid-year preparatory meeting and agreed to vital next steps at the 30th Meeting of the Parties in 2018. Throughout meetings in 2018 and 2019, negotiators spent significant time discussing the scope of actions at the Montreal Protocol needed to discover and prevent illegal production or consumption of controlled substances. There were differences of opinion on whether the contact group on this issue should be forward-looking and review institutional matters and processes, or should it focus more on accountability and unanswered questions about the illegal production and emissions. Protracted discussions covered gathering more information on the current situation, analyzing institutional processes to avoid similar situations in the future and finding constructive ways forward leading to important decisions directing the Technology and Economic Assessment Panel (TEAP) to provide more information. Unfortunately, key conversations on how to undertake a comprehensive fitness check of the Montreal Protocol were not finished in the last physical meeting of the Parties in 2019 in Rome and must continue.

A Major Victory, Without Time for Complacency

Today, scientists report global levels of CFC-11 are close to pre-2008 averages, meaning we are likely back on track! Emissions have not yet reached levels expected under the complete ODS phase out, however, and there is more work to be done to fully understand the drivers and lasting impacts of this environmental crime.

The Montzka analysis also finds that foam banks of CFC-11 have been augmented by 90-725Gg, or up to 3.4 billion tonnes of CO2e. The absence of comprehensive data regarding the size of current banks of CFC-11 in PU foam and other products or equipment has been a major limitation in quantifying remaining emissions from illegal production so far. The Montreal Protocol controls production and consumption but overlooks significant emissions from ‘banks’, that is CFCs contained in existing products. Studies estimate CFC banks across sectors could delay the recovery of the ozone hole by as much as 6 years, adding up to 10 Gt CO2e of climate pollution.

It is imperative to unpack the drivers that led to the widespread use of a banned chemical in the first place. Many of the companies we contacted in 2018 said they preferred CFC-11 because it was cheaper and “more effective” than other blowing agents, underscoring the need for greater awareness among end-users – including technical options, financial assistance to aid transition and serious repercussions of circumventing the law. As demand for insulating and polyurethane foam in China continues to grow exponentially, failing to address the underlying drivers will only be a stopgap solution.

Lessons for the Montreal Protocol

Despite being lauded as the most successful environmental treaty, illegal trade in controlled substances has remained a challenge for the Montreal Protocol since the 1990s. The discovery of large-scale production and use of CFC-11 could be a salutary lesson that we cannot take full recovery of the ozone layer for granted, and the policies and institutions of the Montreal Protocol need to evolve continuously. This is particularly urgent given the new challenges associated with a global phase-down of another class of gases, HFCs under the Kigali Amendment in 2019, while HCFCs are also being phased out in several regions.

  1. Strengthen Enforcement: Smuggling of CFCs, particularly for the refrigerant market, began following the first wave of CFC phase-outs and continues to this day. The Protocol has not invested in regular environmental monitoring of controlled substances and must now strengthen its compliance and enforcement regime so it is fit-for-purpose. Currently Parties to the Montreal Protocol, often despite limited capacity for enforcement and monitoring, are expected to self-report their own non-compliance.
  2. Address Feedstocks and by-products: There is also a need for better monitoring of feedstock production and uses. Close to 500,000 tonnes were reported as production in 2016, with CFCs, CTC and methyl chloroform accounting for 97% of that production. This includes over 156,000 tonnes of CFCs for feedstock uses. The continued production of feedstocks of otherwise controlled substances helps perpetuate risks of byproduct emissions and diversions to illegal emissive markets. Emissions from chemicals released as by-products (such as HFC-23) are also not comprehensively controlled under the Protocol. Increasing feedstock use of HCFC-22, including to make HFOs, makes this a particularly pressing issue for success in the next chapter of the Montreal Protocol.
  3. Search, Reuse, & Destroy Banks: Montreal Protocol must address safe recovery and destruction of banks. Mitigation of banks of fluorinated gases represents the most impactful near-term strategy to achieve deeper mitigation of F-gases.
  4. Modernize Enforcement: While much of the institutions and capacity were put in place in previous decades, there is an opportunity for the Protocol and its Parties to explore technology to design modern national traceability systems that could provide end-to-end visibility of production, transport and use of controlled substances by securely and seamlessly exchanging information in real time. For example, blockchain technology can help ensure provenance, providing traceability across the supply chain without giving away proprietary information, thwarting counterfeiters and allowing traceability for monitoring and enforcement. There are examples of environmental governance systems and industry already using mechanisms such as electronic permitting and GPS-enabled devices in real time to track transport of chemicals
  5. Encompass other ODS: Other scientific papers show that CFC-11 is just one of several chemicals that are known problems, including recent findings on CFCs-113 and 113a, carbon tetrachloride (CTC), and other HCFCs. Emissions of nitrous oxide, now the most significant ozone-depleting emissions, as well as the third most important GHG by radiative forcing are accelerating too. These emissions could undermine not just the slowly healing ozone but also the global efforts to battle climate change.


To avoid catastrophic climate tipping points, we need to limit global temperature rise to under 1.5°C, but right now, we are not on course to ensure staying under that threshold. Montreal Protocol, therefore, must do its part by reining in rogue emissions of not only its original controlled substances but all ODSs and their substitutes that contribute to climate change. Lessons must be learned and institutional changes swiftly applied to ensure that all Parties are able to comply with the critical obligations under the Protocol and maximize global efforts to combat global warming and ensure the recovery of the ozone layer. The Montreal Protocol has achieved unparalleled success in the past decades, but needs to revamp itself to sustain its reputation in the climate reality of the 21st century.