Scientists Discover Four New Ozone-Depleting Gases

European and Australian researchers have identified three new ozone-depleting chlorofluorocarbons, dubbed CFC-112, CFC-112a, CFC-113a, and one new ozone-depleting hydrochlorofluorocarbon, HCFC-133a, in the atmosphere of our planet.

Scientists have discovered four new man-made gases – CFC-112, CFC-112a, CFC-113a and HCFC-133a – all of which are contributing to the destruction of the ozone layer. Image credit: NASA.

They made the discovery by comparing today’s air samples with air trapped in polar firn snow – which provides a century-old natural archive of the atmosphere.

They also looked at air collected between 1978 and 2012 in unpolluted Tasmania.

Measurements show that CFC-112, CFC-112a, CFC-113a and HCFC-133a have been released into the atmosphere recently – and that two are significantly accumulating.

Emission increases of this scale have not been seen for any other chlorofluorocarbons since controls were introduced during the 1990s.

But they are nowhere near peak CFC emissions of the 1980s which reached around a million tones a year.

“Our research has shown four gases that were not around in the atmosphere at all until the 1960s which suggests they are man-made,” said Dr Johannes Laube from the University of East Anglia, UK, who is the lead author of a paper published in the journal Nature Geoscience.

“CFCs are the main cause of the hole in the ozone layer over Antarctica. 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. However, legislation loopholes still allow some usage for exempted purposes.”

Dr Laube and his colleagues estimate that, before 2012, emissions of CFC-112, CFC-112a, CFC-113a and HCFC-133a combined amounted to more than 74,000 tones.

“The identification of these four new gases is very worrying as they will contribute to the destruction of the ozone layer. We don’t know where the new gases are being emitted from and this should be investigated. Possible sources include feedstock chemicals for insecticide production and solvents for cleaning electronic components,” Dr Laube said.

“What’s more, the three CFCs are being destroyed very slowly in the atmosphere – so even if emissions were to stop immediately, they will still be around for many decades to come.”

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Laube JC et al. Newly detected ozone-depleting substances in the atmosphere. Nature Geoscience, published online March 09, 2014; doi: 10.1038/ngeo2109