Ozone-depleting substances emitted through human activities cause large-scale damage to the stratospheric ozone layer, and influence global climate. Consequently, the production of many of these substances has been phased out; prominent examples are the chlorofluorocarbons (CFCs), and their intermediate replacements, the hydrochlorofluorocarbons (HCFCs). So far, seven types of CFC and six types of HCFC have been shown to contribute to stratospheric ozone destruction1,2. Here, we report the detection and quantification of a further three CFCs and one HCFC. We analysed the composition of unpolluted air samples collected in Tasmania between 1978 and 2012, and extracted from deep firn snow in Greenland in 2008, using gas chromatography with mass spectrometric detection. Using the firn data, we show that all four compounds started to emerge in the atmosphere in the 1960s. Two of the compounds continue to accumulate in the atmosphere. We estimate that, before 2012, emissions of all four compounds combined amounted to more than 74,000 tonnes. This is small compared with peak emissions of other CFCs in the 1980s of more than one million tonnes each year2. However, the reported emissions are clearly contrary to the intentions behind the Montreal Protocol, and raise questions about the sources of these gases.
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We are grateful for financial support from the UK Natural Environment Research Council (Research Fellowships NE/F015585/1 and NE/I021918/1, Research Award NE/F021194/1 and the National Centre for Atmospheric Science). We thank the staff at the Cape Grim station and at CSIRO GASLAB Aspendale for collecting and maintaining the Cape Grim air archive and preparing the UEA flask and sub-samples. We also acknowledge CSIRO and the Bureau of Meteorology for financially supporting these activities. NEEM is directed and organized by the Center of Ice and Climate at the Niels Bohr Institute and US NSF, Office of Polar Programs. It is supported by funding agencies and institutions in Belgium (FNRS-CFB and FWO), Canada (GSC), China (CAS), Denmark (FIST), France (IPEV, CNRS/INSU, CEA and ANR), Germany (AWI), Iceland (RannIs), Japan (NIPR), Korea (KOPRI), The Netherlands (NWO/ALW), Sweden (VR), Switzerland (SNF), United Kingdom (NERC) and the USA (US NSF, Office of Polar Programs). The Geophysica flights from Oberpfaffenhofen were financially supported by ESA under the PremieEx project and by Forschungszentrum Jülich. The Geophysica flights from Kiruna were financially supported by the EC as part of the FP7 project RECONCILE (Grant number: RECONCILE-226365-FP7-ENV-2008-1). Air sampling during these campaigns was financially supported by the Dutch Science foundation (NWO, grant number 865.07.001). The research leading to these results has received financial support from the European Community’s Seventh Framework Programme (FP7/2007–2013) in the InGOS project under grant agreement 284274. In addition we are grateful for contributions from G. Mutisya (Ozone Secretariat), P. A. Newman (NASA), S. Allin (UEA), T. F. Duindam and M. Bolder (Utrecht University), all CARIBIC partners, the Geophysica team (discussions, software help, sample collection and campaign organization) and from the NOAA-ESRL GMD, AGAGE and WMO GAW teams (provision of publicly available data). P.M. is part of Labex OSUG@2020 (ANR10 LABX56).
The authors declare no competing financial interests.
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Laube, J., Newland, M., Hogan, C. et al. Newly detected ozone-depleting substances in the atmosphere. Nature Geosci 7, 266–269 (2014). https://doi.org/10.1038/ngeo2109
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