Two new chlorofluorocarbons (CFCs), the main cause of the hole in the ozone layer over Antarctica, and one new hydrochlorofluorocarbon (HCFC) have been found in the atmosphere.
And the researchers who identified the gases say we need to find where they’re coming from. Possible sources include industrial solvents, feedstock chemicals and refrigerants.
Laws to reduce and phase out CFCs came into force in 1989, followed by a total ban in 2010. This has resulted in successfully reducing the production of many of these compounds on a global scale.
The research, published today in the journal Atmosphere, comes after another four man-made gases were discovered by the same team in March.
The scientists made the discovery by comparing today’s air samples with air collected between 1978 and 2012 in unpolluted Tasmania and samples taken during aircraft flights.
Measurements show that all but one of the new gases have been released into the atmosphere in recent years.
Dr Johannes Laube of the University of East Anglia said two of the gases found earlier in the year were particularly worrying because they were still accumulating significantly up until 2012.
Emission increases of this scale have not been seen for any other CFCs since controls were introduced during the 1990s, but they are nowhere near peak CFC emissions of the 1980s.
“We have now identified another two CFCs and one HCFC, although these have much lower concentrations than the previous ones,” he says.
“It is therefore unlikely that they will pose a threat to the ozone layer. They do however strengthen our argument that there are many more gases out there and the sum of them may well have an impact.”
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