AI Insight
Industrial emissions of ozone-depleting feedstock chemicals such as HCFCs, CFCs, and carbon tetrachloride are occurring at significantly higher rates than previously assumed, with 4% of these substances escaping into the atmosphere rather than the estimated 0.5%. Industrial use of these compounds has increased by 160% since 2000, and researchers project this trend will continue until 2100. These emissions could delay the full recovery of the stratospheric ozone layer by six to eleven years beyond the previously estimated date of 2066, and may generate approximately 300 million tonnes of CO2-equivalent greenhouse gas emissions by 2050.
Why it matters
Because feedstock chemical use is currently exempt from Montreal Protocol restrictions, new international regulatory frameworks and industry cooperation will likely be necessary to prevent further setbacks to ozone recovery and to limit the associated climate warming effects of these potent greenhouse gases.
Understand the Science
Emissions of certain ozone-depleting chemicals used in industry could delay the recovery of the Earth’s ozone layer by as much as 11 years, according to researchers. Lowering these emissions would help both the ozone layer to heal and reduce the climate heating impacts of such chemicals.
The 1987 Montreal Protocol banned the global production and use of ozone-depleting chemicals – such as hydrochlorofluorocarbons (HCFCs) – for refrigeration and as foaming agents. However, there are no restrictions on the use of such chemicals as feedstocks to make other molecules. This applies to HCFCs, carbon tetrachloride, chlorofluorocarbons (CFCs) and other long-lived chlorinated and brominated compounds.
Industrial experts assumed that only 0.5% of these feedstock chemicals would escape into the atmosphere and that the use of these substances by the chemical industry would decline. ‘[However], feedstock chemicals are now being released in increased quantities during production, transport and further processing,’ said Stefan Reimann, an atmospheric scientist at the Swiss Federal Laboratories for Materials Science and Technology. ‘And the volumes currently being produced are significantly larger than was assumed 30 years ago.’
Reimann and his team have now found that 4% of these feedstock chemicals are released to the atmosphere, and that industrial use of these compounds has increased by 160% since 2000. The team predicts that the use of these chemicals will continue to rise until 2100.
Earlier estimates suggested that the stratospheric ozone layer would fully recover in 2066, but the researchers say that these industrial emissions could delay the recovery by six to 11 years.
These ozone-depleting chemicals are also powerful greenhouse gases, with some HCFCs being nearly 2000 times more potent than carbon dioxide. Analysis suggested that continuing to release these chemicals at the same rate will lead to around 300 million tonnes of equivalent CO2 emissions by 2050. This is around 1% of anthropogenic CO2 emissions in 2024 – equivalent to France’s annual CO2 emissions.
‘The Montreal protocol was successful because science, politics and industry worked closely together,’ says Reimann. ‘Such cooperation is crucial again today to address new challenges.’