Newly detected ozone-depleting substances in the atmosphere

Journal name:
Nature Geoscience
Volume:
7,
Pages:
266–269
Year published:
DOI:
doi:10.1038/ngeo2109
Received
Accepted
Published online

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.

References

  1. Scientific Assessment of Ozone Depletion: 2002, Global Ozone Research and Monitoring Project Report No. 47 (World Meteorological Organization, (2003).
  2. Scientific Assessment of Ozone Depletion: 2010, Global Ozone Research and Monitoring Project Report No. 52 (World Meteorological Organization, (2011).
  3. Farman, J. C., Gardiner, B. G. & Shanklin, J. D. Large losses of total ozone in Antarctica reveal seasonal ClOx/NOx interaction. Nature 315, 207210 (1985).
  4. Scientific Assessment of Stratospheric Ozone: 1989, Global Ozone Research and Monitoring Project Report No. 20 (World Meteorological Organization, (1990).
  5. Martinerie, P. et al. Long-lived halocarbon trends and budgets from atmospheric chemistry modelling constrained with measurements in polar firn. Atmos. Chem. Phys. 9, 39113934 (2009).
  6. Fraser, P. J., Oram, D. E., Reeves, C. E., Penkett, S. A. & McCulloch, A. Southern hemispheric halon trends (1978–1998 and global halon emissions). J. Geophys. Res. 104, 1598515999 (1999).
  7. Oram, D.E. et al. Long-term tropospheric trend of octafluorocyclobutane (c-C4F8 or PFC-318). Atmos. Chem. Phys. 12, 261269 (2012).
  8. Buizert, C. et al. Gas transport in firn: Multiple-tracer characterisation and model intercomparison for NEEM, Northern Greenland. Atmos. Chem. Phys. 12, 42594277 (2012).
  9. Laube, J. C. et al. Distributions, long term trends and emissions of four perfluorocarbons in remote parts of the atmosphere and firn air. Atmos. Chem. Phys. 12, 40814090 (2012).
  10. Laube, J. C. et al. Observation-based assessment of stratospheric fractional release, lifetimes, and ozone depletion potentials of ten important source gases. Atmos. Chem. Phys. 13, 27792791 (2013).
  11. Volk, C. M. et al. Evaluation of source gas lifetimes from stratospheric observations. J. Geophys. Res. 102, 2554325564 (1997).
  12. Solomon, S., Tuck, A. F., Mills, M., Heidt, L. E. & Pollock, W. H. On the evaluation of ozone depletion potentials. J. Geophys. Res. 97, 825842 (1992).
  13. Newland, M. J. et al. Southern hemispheric halon trends and global halon emissions, 1978–2011. Atmos. Chem. Phys. 13, 55515565 (2013).
  14. Cuzzato, P. et al. Process to obtain CFC-113a from CFC-113. US Patent Application 2002/0151755 (2002)
  15. Gervasutti, C. Process for preparing fluoroethylenes and chlorofluoro-ethylenes from chlorofluoroethanes. US Patent 4,876,405 (1989)
  16. Buchwald, H. et al. Difluorotetrachloroethane mixtures and their use in removing waxes. US Patent 4,906,304 (1990)
  17. Manzer, L. E. The CFC-ozone issue: Progress on the development of alternatives to CFCs. Science 249, 3135 (1990).
  18. Kuijpers, L. & Seki, M. UNEP Report of the Technology and Economic Assessment Panel Vol. 1 (UNEP Ozone Secretariat, (2013).
  19. Dahl-Jensen, D. et al. Eemian interglacial reconstructed from a Greenland folded ice core. Nature 493, 489494 (2013).
  20. Witrant, E. et al. A new multi-gas constrained model of trace gas non-homogeneous transport in firn: Evaluation and behaviour at eleven polar sites. Atmos. Chem. Phys. 12, 1146511483 (2012).
  21. Witrant, E. & Martinerie, P. Proc. 5th IFAC Symp. System Structure and Control Input Estimation from Sparse Measurements in LPV Systems and Isotopic Ratios in Polar Firns. 659664 (2013).

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Affiliations

  1. Centre for Ocean and Atmospheric Sciences, School of Environmental Sciences, University of East Anglia, Norwich Research Park Norwich NR4 7TJ, UK

    • Johannes C. Laube,
    • Mike J. Newland,
    • Christopher Hogan,
    • Claire E. Reeves &
    • William T. Sturges
  2. Max Planck Institute for Chemistry, Air Chemistry Division, Hahn-Meitner-Weg 1 55128 Mainz, Germany

    • Carl A. M. Brenninkmeijer
  3. Centre for Australian Weather and Climate Research, Commonwealth Scientific and Industrial Research Organisation, Aspendale, Victoria 3195, Australia

    • Paul J. Fraser
  4. CNRS, LGGE, F-38041 Grenoble, France

    • Patricia Martinerie
  5. Univ. Grenoble Alpes, LGGE, F-38041 Grenoble, France

    • Patricia Martinerie
  6. National Centre for Atmospheric Science, School of Environmental Sciences, University of East Anglia, Norwich Research Park Norwich NR4 7TJ, UK

    • David E. Oram
  7. Institute for Marine and Atmospheric Research, Utrecht University, Princetonplein 5 3584 CC Utrecht, The Netherlands

    • Thomas Röckmann
  8. Physics Institute, University of Berne, Sidlerstrasse 5 CH-3012 Bern, Switzerland

    • Jakob Schwander
  9. UJF—Grenoble1 / CNRS, Grenoble Image Parole Signal Automatique (GIPSA-lab), UMR 5216, B.P. 46 F-38402 St Martin d’Hères, France

    • Emmanuel Witrant
  10. Present address: School of Geography, College of Life and Environmental Sciences, University of Birmingham, Birmingham B15 2TT, UK.

    • Mike J. Newland

Contributions

J.C.L. and C.H. performed the measurements, M.J.N. and C.E.R. modelled the emissions and P.M. and E.W. the firn air data. C.A.M.B., P.J.F., D.E.O., T.R. and J.S. collected and provided air samples and all authors contributed to the interpretation and the writing of the manuscript.

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The authors declare no competing financial interests.

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