Record Emission Levels of Five Banned Ozone-Depleting Compounds Recorded

The researchers warn that emissions of many ozone-depleting chemicals banned by the Montreal Protocol 13 years ago are on the rise.

The report says that so-called “chlorofluorocarbons” or man-made chlorofluorocarbons (CFCs) have reached record levels, boosting climate change-related emissions.

The amount of five ozone-depleting CFCs in the atmosphere increased rapidly between 2010 and 2020, reaching record levels.

CFCs were commonly used in refrigerators, aerosols, solvents and aerosol dispensers until their production was banned worldwide after they were found to be a major contributor to ozone layer damage.

The Montreal Protocol, approved in 1987, requires the rapid phase-out of some CFCs and the slower phase-out of others.

However, CFCs are still allowed to be used as intermediates—a raw material used to make another compound—and by-products in the manufacture of other chemicals. CFCs produced in this manner are not subject to the Protocol.

The release of small CFCs now appears to be increasing as a by-product of the production of ozone-friendly alternatives to CFCs called hydrofluorocarbons (HFCs).

Three of the measured CFCs (CFC-113a, CFC-114a, CFC-115) are known to be used in the production of chemicals, and the remaining two (CFC-112a and CFC-113) are unknown.

The authors of a study published today in the journal Nature Geoscience calculated that the combined emissions of five CFCs in 2020 were equivalent to 4,200 tons of CFC-11, the second most abundant CFC controlled substance under the Montreal Protocol.

As for the warming effect, scientists note that this amounted to 47 million tons of carbon dioxide, equivalent to 150% of London’s 2018 CO2 emissions.

Although the impact of the cumulative emissions of these five CFCs between 2010 and 2020 on the ozone layer is small, the authors caution that continued increases at current rates could reverse some of the gains made under the Montreal Protocol and could have additional climate implications.

The full results of the study are published in the journal Nature Geoscience. The measurements were taken by the University of Bristol, the US National Oceanic and Atmospheric Administration (NOAA) Global Observatory, and the University of East Anglia and the Julich Research Center.

Source: Metro