The latest data from NASA satellites show that our ozone layer is recovering and that a short-lived resurgence in the emission of ozone-depleting pollutants in eastern China will not significantly delay the revival of Earth’s protective “sunscreen” layer. Human activities effectively punched a hole in it, through the use of gases like chlorofluorocarbons (CFCs) in spray cans and refrigerants, which break down ozone molecules in the upper atmosphere.

Ozone-depleting substances (ODSs) mainly include chlorofluorocarbons (CFCs), halons, carbon tetrachloride (CTC), methyl chloroform (TCA), hydrochlorofluorocarbons (HCFCs), hydrobromofluorocarbons (HBFCs), and bromochloromethane (BCM). This study quantifies the banks, emissions, and environmental impacts of China’s ODSs and hydrofluorocarbon substitutes during 1980–2020. It compiles emission inventories for major ODSs and finds that China’s emissions of first-generation ODSs decreased markedly after implementation of the Montreal Protocol, although banks of some ODSs still pose future emission risks.

Ozone-depleting substances (ODSs), which also contribute to global warming, have been controlled by the Montreal Protocol (MP) since 1987. China joined the MP in 1991 and began reducing production and consumption of ODSs in the country, leading to a decrease in emissions of ODSs. The avoided cumulative ODS consumption and emission values of 10.8 and 5.8 (4.8-6.9) million tonnes (Mt) of CFC-11-equivalent (eq), respectively, were estimated by comparing the two scenarios. The MP implemented by China has resulted in substantial environmental benefits over the last 30 years. However, owing to the massive use of HFCs as substitutes, the cumulative emissions reached 2286 Mt CO2-eq during 1990-2020, and it will be challenging to phase down HFCs in the environment after China ratified the Kigali Amendment in 2021.

Global emissions of the ozone-destroying chlorofluorocarbon CFC-11 fell suddenly between 2018 and 2019, largely driven by reductions from within China, according to new analysis in Nature. A 2019 study had estimated that 40–60% of the global rise in CFC-11 emissions after 2012 came from China, implying illegal production and use, but the new work shows that average global CFC-11 emissions between 2018 and 2019 fell by 26%, returning to pre-2012 levels. Computer models indicate that around 60% of this observed global decrease in CFC-11 emissions appears to have come from China, reflecting enforcement actions taken there.

With United Nations support, the Government of China has agreed to completely eliminate its industrial production of ozone-depleting substances (ODS) and hydrochlorofluorocarbons (HCFCs) by 2030. According to data provided by UNEP, China produces 92 per cent of the total HCFC production of developing countries with most of the chemicals supplied to the world’s refrigeration, air conditioning and foam manufacturing sectors. China will close and dismantle its production lines producing only HCFCs for uses controlled under the Montreal Protocol and ensure that any HCFC plants that will receive funding do not switch to producing HCFCs as industrial feedstock.

Since acceding to the Montreal Protocol, China has fulfilled its obligations under the Protocol, achieving compliance targets of all phases and continuously strengthening the life-cycle refrigerant management during the process of refrigerant replacement. In 2010, China released the Regulation on the Administration of Ozone-Depleting Substances, and in December 2023, a newly revised version of the Regulation was released, which came into effect in March 2024. Entities engaged in recovery, reclamation, or destruction shall conduct environmentally sound management of controlled substances in accordance with regulations and are prohibited from direct emissions. In April 2025, China issued the Country Program for Implementing the Montreal Protocol on Substances that Deplete the Ozone Layer (2025–2030).

New research has identified two additional regions of Asia as contributing to rising emissions of the banned ozone‑destroying chemical CFC‑11 that were first reported in 2018. Using measurements from stations in Japan and Korea, scientists concluded that eastern China was the source of about half of the global rise in CFC‑11 emissions after 2012, but they also found evidence that parts of South Korea and western Japan contributed to the remaining increase. The study underscores that multiple regions in Asia, not only China, were responsible for the unexpected CFC‑11 emissions.

The United Nations body that supports developing countries to phase out substances that damage the ozone layer will provide China with up to US$380 million in funding to eliminate industrial production of the ozone‑depleting substances HCFCs by the year 2030. China – the world’s largest producer and consumer of HCFCs – is set to retire its current HCFC production capacity, as well as surplus production capacity, under an agreement with the Multilateral Fund for the Implementation of the Montreal Protocol. The Chinese government says the total amount of HCFCs to be eliminated by 2030 will prevent the emission of over 4.3 million metric tonnes of HCFCs and 8 billion tonnes of CO2‑equivalent greenhouse gas emissions.

A mysterious spike in emissions of an ozone-destroying gas has been tracked to northeast China, where scientists suspect that the chemical is being produced and used in violation of international law. The gas, CFC-11, was once commonly used to make foam insulation for buildings but was supposed to be phased out globally by 2010 under the Montreal Protocol. The study finds that emissions from eastern China account for at least 40–60% of the global rise in CFC-11 emissions since 2013.

Ozone‑depleting substances (ODS) include chlorofluorocarbons (CFCs), hydrochlorofluorocarbons (HCFCs), halons, methyl bromide, carbon tetrachloride, hydrobromofluorocarbons, chlorobromomethane, and methyl chloroform. These compounds contribute to stratospheric ozone depletion, and their impact is quantified by ozone depletion potential (ODP). The ODP of CFC‑11 is defined as 1.0; other CFCs and HCFCs have ODPs that range from 0.01 to 1.0, while halons have ODPs up to 10, indicating their strong ozone‑destroying capacity.

On 9 April 2025, China’s Ministry of Ecology and Environment, together with several other ministries, issued the National Plan on the Implementation of the Montreal Protocol on Substances that Deplete the Ozone Layer (2025–2030). The National Plan strengthens China’s management of ozone-depleting substances (ODSs) and climate-polluting hydrofluorocarbons (HFCs). The Plan describes implementation measures that span the full lifecycle of ODSs and HFCs, including upstream source control, operational process management, end-of-life treatment, and transboundary trade controls. Among specific measures: as of 1 January 2026, it is prohibited to manufacture refrigerators and freezers using HFCs as refrigerants, and as of 1 January 2029, it is prohibited to manufacture room air conditioners for domestic sale using refrigerants with GWP > 750.

On 9 February 2026, the China Ministry of Ecology and Environment (MEE) issued the Circular on Further Strengthening the Management of Ozone-Depleting Substances (ODSs) and Hydrofluorocarbons (HFCs), which takes effect on 1 March 2026. The Circular strengthens controls on production, use, and disposal of ODSs and HFCs, including improved lifecycle management and enforcement against illegal activities. This measure builds on China’s existing regulatory framework under the Regulation on the Administration of Ozone-Depleting Substances and its Country Program for Implementing the Montreal Protocol (2025–2030).

China, the world's largest producer of chlorofluorocarbons (CFC) and halon, today shut down five of its six remaining plants, putting the country two and a half years ahead of the Montreal Protocol's 2010 deadline for phase-out of the two ozone depleting chemicals. The shut down of the five facilities will bring China's production of CFCs to just about 550 metric tons, down from 55,000 metric tons at its peak in 1998. Thirty-one CFC/halon-producing factories have already been shut down earlier by Chinese authorities with support from the World Bank and the Montreal Protocol's Multilateral Fund, demonstrating China's continued commitment to meet its obligations under this treaty to phase out these chemicals.

An environmental organization has revealed new information indicating that China is responsible for the re-emergence of a prohibited industrial gas that not only harms the Earth’s protective ozone layer but also contributes to climate change. The substance in question, trichlorofluoromethane, commonly known as CFC-11, is meant to be eliminated globally in accordance with the Montreal Protocol. Subsequent investigations conducted by The New York Times and Environmental Investigation Agency identified unregulated factories in China as a probable primary contributor to this issue.

Measurements from the Shangdianzi regional background station and an urban site in Beijing were used to derive emissions of major ozone‑depleting halocarbons from China. The study found that emissions of most first‑generation ozone‑depleting substances (CFCs, halons, and some other compounds) had declined in recent years, suggesting compliance with the regulations of China’s advanced phase‑out schedule under the Montreal Protocol. However, emissions of some replacement compounds such as HCFC‑22 were still increasing, reflecting growing use in refrigeration and air‑conditioning.

Using data from Korean and Japanese stations, it appeared around half of the increase in global emissions of CFC-11 originated from parts of eastern China. Further investigation by media and environmental campaigners exposed usage of CFC-11 in the manufacture of insulating foams in China. Chinese authorities took notice and at meetings of the Montreal Protocol in 2018 and 2019, they confirmed some banned ozone depleting substances were identified during factory inspections, but only in small amounts relative to those inferred from the atmospheric data. According to their reports, arrests, material seizures, and the demolition of production facilities within China ensued. The latest evidence indicates that those efforts have likely contributed to dramatic emission declines, and global CFC-11 emissions are now back on the decline.

Recent research published in Nature reveals that global emissions of CFC-11, the second most prevalent ozone-depleting gas, have risen since 2013, primarily due to increased emissions from eastern China. These findings strongly indicate a breach of the Montreal Protocol. Between 2014 and 2017, emissions were approximately 7,000 tonnes per year higher than those recorded from 2008 to 2012, representing more than a twofold increase in emissions from that region and accounting for 40–60% of the global rise. The most likely explanation for this surge is that CFC-11 was still being manufactured despite the global ban, with investigations suggesting ongoing production and use of CFC-11 in China as recently as 2018.

Consumption of controlled substances in ODP tonnes or in CO2-eq tonnes is reported for each Party to the Montreal Protocol. The data table shows China’s consumption of various controlled substances over time. These official data, submitted by China and compiled by the Ozone Secretariat, are used to assess compliance with phase-out schedules for ozone-depleting substances. China’s reported consumption levels follow the downward trajectories required under the Protocol for CFCs and other fully phased-out substances, while HCFC consumption is being reduced according to the agreed schedule.

Despite the Montreal Protocol's overall success, there have been setbacks. In 2018, for example, the concentration of CFC-11, banned since 2010, was found to not be coming down as quickly as was expected, suggesting undeclared emissions were coming from somewhere. The Environmental Investigation Agency traced the emissions to factories in China, which were manufacturing it for use in insulation foam. Once made public, the Chinese government quickly clamped down and scientists say we are now back on track.

This study investigated unintended emissions of ozone‑depleting substances from iron and steel production processes in China. It found that sintering was the major emission process of several ODSs, including chlorofluorocarbons (CFCs), hydrochlorofluorocarbons (HCFCs), halons, methyl halide, and other halogenated compounds. The authors concluded that industrial processes such as sintering can be overlooked sources of ODS emissions, and that mitigation measures in these sectors could further reduce China’s contribution to global ozone‑depleting substance emissions.

We provide, for the first time, comprehensive information on ozone-depleting substances (ODSs) and replacement hydrofluorocarbon (HFC) emissions in China starting from 1980 based on atmospheric measurements and bottom-up data. The paper reports changes in emissions of various ODSs (including CFCs, HCFCs, halons) from China, showing significant increases in production and emissions through the 1990s followed by decreases as Montreal Protocol controls took effect. The study highlights that China is a major contributor to global ODS and HFC emissions but also that emissions trends have changed markedly under international regulations.

Carbon tetrachloride (CCl4) is a long-lived ozone-depleting substance whose production and consumption for dispersive uses have been phased out under the Montreal Protocol since 2010. However, substantial emissions of CCl4 persist globally, potentially delaying ozone layer recovery, with ~30–40% of the sources of global emissions remaining largely unknown. Here, we focus on CCl4 emissions in China, a major contributor to global halocarbon emissions. Based on long-term atmospheric observations from a Chinese network and a top-down inverse modeling approach, we identified substantial CCl4 emissions in China during 2011–2021, accounting for approximately half of the global emissions. A large portion of the top-down emissions in China likely originates from other unknown sources beyond allowed feedstock use, CFC-11 production related activities, and by-product emissions in chlorine-related processes.

Through the Montreal Protocol, the nations of the world agreed to phase out production of substances that damage the ozone layer. But scientists identified an increase of emissions of the phased-out, ozone-depleting substance CFC-11 from Eastern China from 2014 to 2017. The United States leads the international response and continues to push China to live up to its obligations and increase its monitoring and enforcement efforts.

China had phased out around 628,000 tonnes of ozone-depleting substances (ODSs) in 1991–2022, accounting for over half of the volume phased out by developing countries. The country has also moved to phase out 280,000 tonnes of ODSs ahead of schedule. Officials stated that China strictly implements its obligations under the Montreal Protocol, strengthening supervision of production, use, import, export, and destruction of ODSs, and cracking down on illegal activities related to ODSs.

A new study published this week in Nature pins down the source of 7,000 metric tons a year of new CFC-11 emissions to the provinces of Shandong and Hebei on the northeastern coast of China. The bulk of these emissions are believed to come from small factories that are using CFC-11, in violation of the Montreal Protocol, to manufacture foam insulation used in refrigerators and buildings. The reported emissions, if continued, will slow the rate at which these chemicals decrease and could delay recovery of the ozone layer by a decade or more, until the end of the century.

While CFC production was winding down in developed countries, it was rising dramatically in developing countries, notably China and India. Such supply and demand dynamics created opportunities for illicit trade in ozone-depleting substances (ODS), including smuggling of CFCs and other regulated chemicals. The report notes that despite the Montreal Protocol’s controls, illegal production and trade of ODS has occurred in the region, requiring stronger enforcement and regional cooperation.

Recently there was a discovery that CFCs were not declining as rapidly as they should. That was traced back to a source from China, and the Chinese government took action and it is now back on track to where it should be. The research led directly to the 1987 Montreal Protocol, an agreement to freeze production and consumption of ozone-depleting substances and later to phase them out.

According to NASA, the hole in the ozone layer has begun to recover as a result of global bans on CFCs under the Montreal Protocol. However, research released in 2019 reported an alarming increase in CFC‑11, pointing to unregulated use in China, with studies estimating that 40–60% of the rise in emissions came from that country. Subsequent work showed that these emissions declined again after 2017–2018 as enforcement actions were taken. Interim replacements for CFCs such as HCFCs also deplete ozone but to a lesser extent, and their phase‑out is underway.

Ozone depletion refers to the thinning of the Earth's ozone layer caused by man-made chemicals, primarily chlorofluorocarbons (CFCs), halons and other related ozone-depleting substances. These concerns led to the adoption of the Montreal Protocol in 1987, which bans the production of CFCs, halons, and other ozone-depleting chemicals. A study published in Nature found that since 2013 emissions that are predominately from north-eastern China have released large quantities of the banned chemical CFC-11 into the atmosphere, and scientists estimate that without action these emissions will delay the recovery of the planet's ozone hole by a decade.

In CGTN’s special series on the UN in China, the United Nations Industrial Development Organization (UNIDO) representative explains that since China ratified the Montreal Protocol in 1991, UNIDO has helped China implement over 50 projects to eliminate ozone-depleting substances in the refrigeration, foam, pharmaceutical and agricultural production sectors. Those projects to clean up China's refrigerating and air-conditioning sector phased out over 10,000 tons of ozone-depleting substances, reduced pollutants equivalent to 33 million tons of CO2, and helped companies increase energy efficiency by up to 12%. The program also helped Chinese manufacturers convert their production lines to ozone- and climate-friendly technologies.

Ozone (O3) pollution has become an urgent environmental problem in China, posing a serious threat to air quality, human health, land ecosystem, and climate change. In polluted regions, surface O3 is generated by the photochemical oxidation of volatile organic compounds (VOCs) and carbon monoxide (CO) in the presence of nitrogen oxides (NOx). This study focuses on tropospheric ozone pollution within China, which is distinct from stratospheric ozone depletion linked to CFCs.

This chart and accompanying analysis show that since the Montreal Protocol entered into force in 1989, global emissions of ozone‑depleting substances have fallen by more than 99%. The dataset is based on UNEP’s assessments of global production and consumption of controlled ozone‑depleting substances, aggregated across all countries including China. The sharp decline demonstrates worldwide compliance with the phase‑out schedule, although some illegal or unintended emissions have been detected in recent years.

Using atmospheric measurements and inverse modeling, this study quantified the contributions of banks of chlorofluorocarbons to ongoing emissions and their impacts on the ozone layer and climate. It showed that despite the production phase‑out, significant amounts of CFCs remain in equipment and foams and are still being emitted over time. The paper highlighted China and other large economies as key locations of such banks, meaning that past industrial production continues to contribute to global ozone depletion even as new production is banned.

"A mysterious rebound in the emissions of ozone-depleting chemicals—despite a global ban stretching back almost a decade—has been traced to eastern China. Research published by an international team today in Nature used a global network of monitoring stations to pinpoint the source of the rogue emissions. According to these data, 40–60% of the increase in emissions seen since 2013 is due to possibly illegal industrial activity in the Chinese provinces of Shandong and Hebei."

Scientific consensus since the 1980s holds that chlorofluorocarbons (CFCs), used in aerosol cans and cooling devices, are responsible for the thinning of the ozone layer and the Antarctic ozone hole. The Montreal Protocol, agreed in 1987, banned CFCs and led to their global phase-out, which has resulted in a gradual recovery of the ozone layer. Illegal emissions, such as those traced to factories in China producing CFC-11, are considered setbacks but do not overturn the overall recovery trajectory.