Ozone-destroying CFC chemicals are on the rise again despite ban

Despite a global ban on the production of these chemicals since 2010, concentrations of some ozone-depleting chlorofluorocarbons (CFCs) in the atmosphere are rising rapidly. Scientists warn.

CFCs were commonly used in refrigerants, aerosol propellants, and solvents until they were discovered to be the driving force behind the depletion of the ozone layer. Under the Montreal Protocol, their production was phased out from 1989 to 2010.

However, Luke Western of the University of Bristol, UK, and his colleagues found a sharp increase in global atmospheric concentrations of five CFC chemicals between 2010 and 2020.

Using data from 14 measurement sites around the world, the researchers found that concentrations of CFC-112a, CFC-113, CFC-113a, CFC-114a, and CFC-115 have increased since 2010 and will increase by 2020. found that atmospheric abundances reach record highs. .

While a surge in emissions is unlikely to significantly impede the recovery of the ozone layer, which is expected to fully recover by the 2060s, the impact of CFC gases on global warming does raise concerns about the findings. That means, the West said at a press conference. .

He told reporters the findings should serve as an “early warning” for countries to crack down on illegal or negligent chemical production.

The amount of these gases emitted in 2020 would have a warming effect equivalent to the total carbon emissions of a country like Switzerland, he said. is.”

Part of the increase in emissions can be explained by the surge in production of hydrofluorocarbons (HFCs), which are widely used as substitutes for CFCs. The production of HFCs can lead to the formation and release of CFCs as by-products.

However, two CFCs in particular, CFC-112a and CFC-113, have no known legal uses, and researchers are uncertain what is driving the increased emissions. “This is really a bit scary,” said Stephan Reimann of the Swiss Federal Institute for Materials Science and Technology at the same briefing.

Western suggested, for example, that factories may be using CFC-112a illegally to make fluorovinyl ethers and solvents. said. “But it is he’s one of the only known uses of CFC-112a so far.”

Likewise, researchers aren’t sure where the emissions are coming from. “It certainly didn’t come from Europe or America,” said team member Isaac Vimont of the US National Oceanic and Atmospheric Administration team. But more than that, it’s not yet clear which countries are the sources of emissions, he said.

In 2018, factories in China were found to be responsible for a surge in CFC-11 emissions. Previous studies have identified East Asia as the source of his CFC-113a and his CFC-115 emissions, and to pinpoint the cause of the current increase in emissions, the region-wide More surveillance is needed, the study authors wrote in their paper.

Under the Kigali Amendment to the Montreal Protocol ratified in 2016, countries agreed to reduce their HFC production and consumption. These are harmless to the ozone layer, but cause climate change.

Western said action under this amendment should also help address CFC emissions. Reducing HFC and CFC emissions would be an “easy win” for the climate, he added.