Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

  • Article
  • Published:

Global increase of ozone-depleting chlorofluorocarbons from 2010 to 2020

Nature Geoscience volume 16, pages 309–313 (2023)Cite this article

Subjects

An Author Correction to this article was published on 18 May 2023

This article has been updated

Abstract

The production of chlorofluorocarbons (CFCs) that would ultimately be released to the atmosphere was banned globally in 2010 under the Montreal Protocol. Here we use measurements combined with an atmospheric transport model to show how atmospheric abundances and emissions of five CFCs increased between 2010 and 2020, contrary to the goals of the phase-out. The Montreal Protocol allows CFC production for use as a feedstock to produce other chemicals. Emissions of CFC-113a, CFC-114a and CFC-115 probably arise during the production of hydrofluorocarbons, which have replaced CFCs for many applications. The drivers behind increasing emissions of CFC-13 and CFC-112a are more uncertain. The combined emissions of CFC-13, CFC-112a, CFC-113a, CFC-114a and CFC-115 increased from 1.6 ± 0.2 to 4.2 ± 0.4 ODP-Gg yr-1 (CFC-11-equivalent ozone-depleting potential) between 2010 and 2020. The anticipated impact of these emissions on stratospheric ozone recovery is small. However, ongoing emissions of the five CFCs of focus may negate some of the benefits gained under the Montreal Protocol if they continue to rise. In addition, the climate impact of the emissions of these CFCs needs to be considered, as their 2020 emissions are equivalent to 47 ± 5 TgCO2.

This is a preview of subscription content, access via your institution

Access options

Buy this article

  • Purchase on Springer Link
  • Instant access to full article PDF
Buy now

Prices may be subject to local taxes which are calculated during checkout

Fig. 1: Atmospheric abundances and growth rates.
Fig. 2: Global emissions weighted by impact on ozone depletion and climate.

Similar content being viewed by others

Data Availability

AGAGE data are available at http://agage.mit.edu/data/agage-data (last accessed 16 November 2022) and https://doi.org/10.15485/1841748 ref. 51. NOAA atmospheric observations are available at https://gml.noaa.gov/aftp/data/hats/PERSEUS/ and https://gml.noaa.gov/aftp/data/hats/cfcs/ (last accessed 16 November 2022). All inputs to the 12-box model and the resultant estimated emissions, mole fractions and their growth rates are available at https://github.com/lukewestern/py12box_laube (last accessed 16 November 2022) or https://doi.org/10.5281/zenodo.7388012 ref. 52, which also contains measurements analysed at UEA/FZJ.

Code Availability

The 12-box model and the inverse method used to quantify emissions are available via GitHub (https://github.com/mrghg/py12box (last accessed 16 November 2022) and https://github.com/mrghg/py12box_invert (last accessed 16 November 2022)) and Zenodo (https://doi.org/10.5281/zenodo.6857447 ref. 53 and https://doi.org/10.5281/zenodo.6857794 ref. 54). Additional code to prepare inputs is available at https://github.com/lukewestern/py12box_laube (last accessed 16 November 2022) and https://doi.org/10.5281/zenodo.7388012 ref. 52.

Change history

References

  1. Braesicke, P. & Neu, J. Scientific Assessment of Ozone Depletion: 2018 Vol. 58 (World Meteorological Organization, 2019).

  2. Newman, P. A. et al. What would have happened to the ozone layer if chlorofluorocarbons (CFCs) had not been regulated? Atmos. Chem. Phys. 9, 2113–2128 (2009).

    Article  Google Scholar 

  3. Chiodo, G. & Polvani, L. M. New insights on the radiative impacts of ozone-depleting substances. Geophys. Res. Lett. 49, e2021GL096783 (2022).

    Article  Google Scholar 

  4. Polvani, L. M., Previdi, M., England, M. R., Chiodo, G. & Smith, K. L. Substantial twentieth-century Arctic warming caused by ozone-depleting substances. Nat. Clim. Change 10, 130–133 (2020).

    Article  Google Scholar 

  5. Montzka, S. A. et al. An unexpected and persistent increase in global emissions of ozone-depleting CFC-11. Nature 557, 413–417 (2018).

    Article  Google Scholar 

  6. Park, S. et al. A decline in emissions of CFC-11 and related chemicals from eastern China. Nature 590, 433–437 (2021).

    Article  Google Scholar 

  7. Lickley, M. et al. Quantifying contributions of chlorofluorocarbon banks to emissions and impacts on the ozone layer and climate. Nat. Commun. 11, 1380 (2020).

  8. Adcock, K. E. et al. Continued increase of CFC-113a (CCl3CF3) mixing ratios in the global atmosphere: emissions, occurrence and potential sources. Atmos. Chem. Phys. 18, 4737–4751 (2018).

    Article  Google Scholar 

  9. Vollmer, M. K. et al. Atmospheric histories and emissions of chlorofluorocarbons CFC-13 (CClF3), ΣCFC-114 (C2Cl2F4), and CFC-115 (C2ClF5). Atmos. Chem. Phys. 18, 979–1002 (2018).

    Article  Google Scholar 

  10. Vollmer, M. K. et al. Abrupt reversal in emissions and atmospheric abundance of HCFC-133a (CF3CH2Cl). Geophys. Res. Lett. 42, 8702–8710 (2015).

    Article  Google Scholar 

  11. Vollmer, M. K. et al. Unexpected nascent atmospheric emissions of three ozone-depleting hydrochlorofluorocarbons. Proc. Natl Acad. Sci. USA 118, e2010914118 (2021).

    Article  Google Scholar 

  12. Burkholder, J. B. Scientific Assessment of Ozone Depletion: 2018 Vol. 58 (World Meteorological Organization, 2019).

  13. Hodnebrog, Ø. et al. Updated global warming potentials and radiative efficiencies of halocarbons and other weak atmospheric absorbers. Rev. Geophys. 58, e2019RG000691 (2020).

    Article  Google Scholar 

  14. Velders, G. J. M. et al. Projections of hydrofluorocarbon (HFC) emissions and the resulting global warming based on recent trends in observed abundances and current policies. Atmos. Chem. Phys. 22, 6087–6101 (2022).

    Article  Google Scholar 

  15. Murphy, A. B., Farmer, A. J. D., Horrigan, E. C. & McAllister, T. Plasma destruction of ozone depleting substances. Plasma Chem. Plasma Process. 22, 371–385 (2002).

    Article  Google Scholar 

  16. Gervasutti, C. Process for preparing fluoroethylenes and chlorofluoro-ethylenes from chlorofluoroethanes. US patent 4,876,405 (1989).

  17. Laube, J. C. et al. Newly detected ozone-depleting substances in the atmosphere. Nat. Geosci. 7, 266–269 (2014).

    Article  Google Scholar 

  18. Laube, J. C. et al. Tropospheric observations of CFC-114 and CFC-114a with a focus on long-term trends and emissions. Atmos. Chem. Phys. 16, 15347–15358 (2016).

    Article  Google Scholar 

  19. Montzka, S. A. et al. A decline in global CFC-11 emissions during 2018−2019. Nature 590, 428–432 (2021).

  20. Greater London Authority London Energy and Greenhouse Gas Inventory (LEGGI) (London Datastore, accessed 28 February 2023); https://data.london.gov.uk/dataset/leggi

  21. Report of the Medical and Chemical Technical Options Committee: 2018 Assessment (MCTOC, 2018).

  22. Nose, M., Takahashi, K. & Shibanuma, T. Method for producing pentafluoroethane. US patent 8,975,455 (2015).

  23. Chemicals Technical Options Committee Chemicals Technical Options Committee (CTOC) 2014 Assessment Report (United Nations Environment Programme, Ozone Secretariat, 2015).

  24. Calvo Buendia, E. et al. 2019 Refinement to the 2006 IPCC Guidelines for National Greenhouse Gas Inventories (IPCC, 2019).

  25. Technology and Economic Assessment Panel Report of the Technology and Economic Assessment Panel, Volume 1: Progress Report (UNEP, 2021).

  26. Reports with Charts (UNEP, Ozone Secretariat, accessed 28 February 2023); https://ozone.unep.org/countries/data?report_type=0&group%5B0%5D=1&period_start=1986&period_end=2021&output_type=odp-CO2e-tonnes

  27. Fleming, E. L., Newman, P. A., Liang, Q. & Daniel, J. S. The impact of continuing CFC-11 emissions on stratospheric ozone. J. Geophys. Res. Atmos. 125, e2019JD031849 (2020).

    Article  Google Scholar 

  28. Pyle, J. A., Keeble, J., Abraham, N. L., Chipperfield, M. P. & Griffiths, P. T. Integrated ozone depletion as a metric for ozone recovery. Nature 608, 719–723 (2022).

    Article  Google Scholar 

  29. Prinn, R. G. et al. History of chemically and radiatively important atmospheric gases from the Advanced Global Atmospheric Gases Experiment (AGAGE). Earth Syst. Sci. Data 10, 985–1018 (2018).

    Article  Google Scholar 

  30. Hall, B. D., Dutton, G. S. & Elkins, J. W. The NOAA nitrous oxide standard scale for atmospheric observations. J. Geophys. Res. Atmos. 112, D09305 (2007).

    Article  Google Scholar 

  31. Laube, J. C. et al. Accelerating growth of HFC-227ea (1,1,1,2,3,3,3-heptafluoropropane) in the atmosphere. Atmos. Chem. Phys. 10, 5903–5910 (2010).

    Article  Google Scholar 

  32. Fraser, P. J., Pearman, G. I. & Derek, N. CSIRO non-carbon dioxide greenhouse gas research. Part 1: 1975–90. Hist. Rec. Aust. Sci. 29, 1–13 (2018).

    Article  Google Scholar 

  33. Miller, B. R. et al. Medusa: a sample preconcentration and GC/MS detector system for in situ measurements of atmospheric trace halocarbons, hydrocarbons, and sulfur compounds. Anal. Chem. 80, 1536–1545 (2008).

    Article  Google Scholar 

  34. Arnold, T. et al. Automated measurement of nitrogen trifluoride in ambient air. Anal. Chem. 84, 4798–4804 (2012).

    Article  Google Scholar 

  35. Langenfelds, R. et al. Archiving of Cape Grim Air (CSIRO, 2014); http://hdl.handle.net/102.100.100/94816?index=1

  36. Mühle, J. et al. Perfluorocyclobutane (PFC-318, c-C4F8) in the global atmosphere. Atmos. Chem. Phys. 19, 10335–10359 (2019).

    Article  Google Scholar 

  37. O’Doherty, S. et al. In situ chloroform measurements at Advanced Global Atmospheric Gases Experiment atmospheric research stations from 1994 to 1998. J. Geophys. Res. Atmos. 106, 20429–20444 (2001).

    Article  Google Scholar 

  38. Montzka, S. A. et al. Recent trends in global emissions of hydrochlorofluorocarbons and hydrofluorocarbons: reflecting on the 2007 adjustments to the Montreal Protocol. J. Phys. Chem. A 119, 4439–4449 (2015).

    Article  Google Scholar 

  39. CAMP—The Chlorofluorocarbon Alternatives Monitoring Project (NOAA Global Monitoring Laboratory, 2015); https://gml.noaa.gov/hats/flask/camp.html

  40. Cunnold, D. M. et al. The Atmospheric Lifetime Experiment: 3. Lifetime methodology and application to three years of CFCl3 data. J. Geophys. Res. Oceans 88, 8379–8400 (1983).

    Article  Google Scholar 

  41. Rigby, M. et al. Re-evaluation of the lifetimes of the major CFCs and CH3CCl3 using atmospheric trends. Atmos. Chem. Phys. 13, 2691–2702 (2013).

    Article  Google Scholar 

  42. Rigby, M., Ganesan, A. L. & Prinn, R. G. Deriving emissions time series from sparse atmospheric mole fractions. J. Geophys. Res. Atmos. 116 (2011).

  43. Rigby, M. et al. Recent and future trends in synthetic greenhouse gas radiative forcing. Geophys. Res. Lett. 41, 2623–2630 (2014).

    Article  Google Scholar 

  44. Cunnold, D. M. et al. Global trends and annual releases of CCl3F and CCl2F2 estimated from ALE/GAGE and other measurements from July 1978 to June 1991. J. Geophys. Res. Atmos. 99, 1107–1126 (1994).

    Article  Google Scholar 

  45. Byrd, R. H., Lu, P., Nocedal, J. & Zhu, C. A limited memory algorithm for bound constrained optimization. SIAM J. Sci. Comput. 16, 1190–1208 (1995).

    Article  Google Scholar 

  46. Ko, M. K. W., Newman, P. A., Reimann, S. & Strahan, S. E. Lifetimes of Stratospheric Ozone-Depleting Substances, Their Replacements, and Related Species SPARC Report No. 6 (SPARC, 2013); http://www.sparc-climate.org/publications/sparc-reports/

  47. Ray, E. A. et al. The influence of the stratospheric quasi-biennial oscillation on trace gas levels at the Earth’s surface. Nat. Geosci. 13, 22–27 (2020).

    Article  Google Scholar 

  48. Ruiz, D. J. et al. How atmospheric chemistry and transport drive surface variability of N2O and CFC-11. J. Geophys. Res. Atmos. 126, e2020JD033979 (2021).

    Article  Google Scholar 

  49. Baldwin, M. P. et al. The quasi-biennial oscillation. Rev. Geophys. 39, 179–229 (2001).

    Article  Google Scholar 

  50. Yang, W. & Zurbenko, I. Kolmogorov–Zurbenko filters. Wiley Interdescip. Rev. Comput. Stat. 2, 340–351 (2010).

    Article  Google Scholar 

  51. Prinn, R. et al. The Advanced Global Atmospheric Gases Experiment (AGAGE) Data (ESS-DIVE, 2022); https://doi.org/10.15485/1841748

  52. Western, L. lukewestern/py12box_laube: minor CFC inputs and outputs v.1.1.1. Zenodo https://doi.org/10.5281/zenodo.7388012 (2022).

  53. Rigby, M. & Western, L. mrghg/py12box v.0.2.1 Zenodo https://doi.org/10.5281/zenodo.6857447 (2022).

  54. Rigby, M. & Western, L. mrghg/py12box_invert v.0.0.2 Zenodo https://doi.org/10.5281/zenodo.6857794 (2022).

Download references

Acknowledgements

We are indebted to UEA, FZJ, NOAA and AGAGE staff and scientists for their dedication to producing high-quality atmospheric trace gas measurements. The AGAGE Medusa GC-MS system development, calibrations and measurements at the Scripps Institution of Oceanography, La Jolla and Trinidad Head, CA, USA; Mace Head, Ireland; Ragged Point, Barbados; Cape Matatula, American Samoa; and Kennaook/Cape Grim, Australia were supported by the NASA Upper Atmospheric Research Program in the United States with grants NNX07AE89G, NNX16AC98G and 80NSSC21K1369 to MIT and NNX07AF09G, NNX07AE87G, NNX16AC96G, NNX16AC97G, 80NSSC21K1210 and 80NSSC21K1201 to SIO. The Department for Business, Energy & Industrial Strategy (BEIS) in the United Kingdom supported the University of Bristol for operations at Mace Head, Ireland (contract 1028/06/2015) and through the NASA award to MIT with sub-award to University of Bristol for Mace Head and Barbados (80NSSC21K1369). The National Oceanic and Atmospheric Administration (NOAA) in the United States supported the University of Bristol for operations at Ragged Point, Barbados (contract 1305M319CNRMJ0028) and operations at Cape Matatula, American Samoa. In Australia, the Kennaook/Cape Grim operations were supported by the Commonwealth Scientific and Industrial Research Organization (CSIRO), the Bureau of Meteorology (Australia), the Department of Climate Change, Energy, the Environment and Water (Australia), Refrigerant Reclaim Australia and through the NASA award to MIT with sub-award to CSIRO for Cape Grim (80NSSC21K1369). Measurements at Jungfraujoch are supported by the Swiss National Programs HALCLIM and CLIMGAS-CH (Swiss Federal Office for the Environment, FOEN) and by the International Foundation High Altitude Research Stations Jungfraujoch and Gornergrat (HFSJG). NOAA measurements were supported in part through the NOAA Cooperative Agreement with CIRES (NA17OAR4320101). L.M.W. received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Słodowska-Curie grant agreement no. 101030750. K.E.A. was funded by the UK Natural Environment Research Council through the EnvEast Doctoral Training Partnership (grant number NE/L002582/1). J.C.L. received funding from the ERC project EXC3ITE (EXC3ITE-678904-ERC-2015-STG).

Author information

Authors and Affiliations

  1. Global Monitoring Laboratory, National Oceanic and Atmospheric Administration, Boulder, CO, USA

    Luke M. Western, Stephen A. Montzka & Isaac Vimont

  2. School of Chemistry, University of Bristol, Bristol, UK

    Luke M. Western, Simon O’Doherty, Matt Rigby & Dickon Young

  3. Empa, Swiss Federal Laboratories for Materials Science and Technology, Dubendorf, Switzerland

    Martin K. Vollmer & Stefan Reimann

  4. Climate Science Centre, CSIRO Oceans and Atmosphere, Aspendale, Victoria, Australia

    Paul B. Krummel, Paul J. Fraser & Ray L. Langenfelds

  5. Centre for Ocean and Atmospheric Sciences, School of Environmental Sciences, University of East Anglia, Norwich, UK

    Karina E. Adcock & David E. Oram

  6. Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, CO, USA

    Molly Crotwell

  7. Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA, USA

    Christina M. Harth, Jens Mühle & Ray F. Weiss

  8. National Centre for Atmospheric Science, University of East Anglia, Norwich, UK

    David E. Oram

  9. Institute of Energy and Climate Research: Stratosphere (IEK-7), Forschungszentrum Jülich, Julich, Germany

    Johannes C. Laube

Authors
  1. Luke M. Western
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Martin K. Vollmer
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Paul B. Krummel
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. Karina E. Adcock
    View author publications

    You can also search for this author in PubMed Google Scholar

  5. Molly Crotwell
    View author publications

    You can also search for this author in PubMed Google Scholar

  6. Paul J. Fraser
    View author publications

    You can also search for this author in PubMed Google Scholar

  7. Christina M. Harth
    View author publications

    You can also search for this author in PubMed Google Scholar

  8. Ray L. Langenfelds
    View author publications

    You can also search for this author in PubMed Google Scholar

  9. Stephen A. Montzka
    View author publications

    You can also search for this author in PubMed Google Scholar

  10. Jens Mühle
    View author publications

    You can also search for this author in PubMed Google Scholar

  11. Simon O’Doherty
    View author publications

    You can also search for this author in PubMed Google Scholar

  12. David E. Oram
    View author publications

    You can also search for this author in PubMed Google Scholar

  13. Stefan Reimann
    View author publications

    You can also search for this author in PubMed Google Scholar

  14. Matt Rigby
    View author publications

    You can also search for this author in PubMed Google Scholar

  15. Isaac Vimont
    View author publications

    You can also search for this author in PubMed Google Scholar

  16. Ray F. Weiss
    View author publications

    You can also search for this author in PubMed Google Scholar

  17. Dickon Young
    View author publications

    You can also search for this author in PubMed Google Scholar

  18. Johannes C. Laube
    View author publications

    You can also search for this author in PubMed Google Scholar

Contributions

L.M.W. and J.C.L. conceived and designed the study. M.K.V., P.B.K., K.E.A., M.C., P.J.F., C.M.H., R.L.L., S.A.M., J.M., S.O’D., D.E.O., S.R., I.V., R.F.W., D.Y. and J.C.L. provided measurement data and analysis. Emissions modelling was designed and performed by L.M.W. and M.R. L.M.W. led the writing of the manuscript with contributions from J.C.L., J.M., M.K.V., K.E.A., I.V., S.R. and M.R., with additional input from all authors.

Corresponding author

Correspondence to Luke M. Western.

Ethics declarations

Competing interests

The authors declare no competing interests.

Peer review

Peer review information

Nature Geoscience thanks Hannah Flerlage, Steve Wofsy, Ross Salawitch and the other, anonymous, reviewer(s) for their contribution to the peer review of this work. Primary Handling Editor: Xujia Jiang, in collaboration with the Nature Geoscience team.

Additional information

Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Extended data

Extended Data Fig. 1 Surface dry-air mole fractions and growth rates for CFCs with increasing abundances.

Surface dry-air mole fractions and growth rates are shown for (a) CFC-13, (b) CFC-112a, (c) CFC-113a, (d) CFC-114a and (e) CFC-115 for the available direct atmospheric record (that is, excluding trends derived from firn air) from 1978 through 2020 (1999 through 2020 for CFC-112a). Circles show measured monthly mean mole fractions and lines are the model estimated mole fractions and growth rates, with the colours indicating the semi-hemispheric modelled estimate in which the measurement was made. Uncertainties (1 sd) are shown by the grey shading and are only shown for the global mean mole fractions and growth rates. Details on previously published records can be found in refs. 8,9,17,18. CFC-13 abundances have increased continuously since 1978. The CFC-13 growth rate was rapid in the 1980s, slowed to 0.015 ppt yr−1 in 2000, and subsequently increased over the next two decades. From 2010 to 2020, CFC-13 increased by 9% from 3.04 ppt to 3.31 ppt (3.44 ppt in 2020 using the NOAA record, only available since 2014; see Extended Data Fig. 2). CFC-112a has the lowest abundance of the five CFCs. Its abundance was declining 1999-2006, but rapidly grew from 2010 to 2020 by 19% from 0.066 ppt to 0.078 ppt. The CFC-113a abundance grew since 1978 at a rate less than 0.02 ppt yr−1 until 2010, but from 2010 to 2020 it grew by 141% from 0.43 ppt to 1.02 ppt. CFC-114a growth rates were rapidly accelerating prior to 1990, then dropped to near zero between 1998–2003, after which they accelerated again. Between 2010 and 2020 CFC-114a increased by 9% from 1.03 ppt to 1.13 ppt. Similar to CFC-13 and CFC-114a, CFC-115 abundances also grew rapidly prior to the 1990s, but the timing is different. CFC-115 growth dropped to close to zero between 2005–2011, after which its growth rate again slowly increased. From 2010 to 2020, CFC-115 abundance grew by 4% from 8.38 ppt to 8.71 ppt (growing from 8.42 to 8.75 ppt from 2010 to 2020, or by 4%, using the NOAA record, Extended Data Fig. 2).

Extended Data Fig. 2 Surface dry-air mole fractions for CFC-13 and CFC-115 measured by the NOAA network.

(a) CFC-13 and (b) CFC-115 hemispheric monthly means (circles) and the annual global mean (black line) derived from measurements from the NOAA network. See the caption of Extended Data Fig. 1 for a discussion of these data.

Extended Data Fig. 3 Surface dry-air mole fractions and growth rates for the structural isomers of CFCs.

As Extended Data Fig. 1 but for (a) CFC-112, (b) CFC-113 and (c) CFC-114. CFC-112, CFC-113 and CFC-114 are structural isomers of CFC-112a, CFC-113a and CFC-114a, respectively. Note that the measurement approach at UEA/FJZ can measure the major isomers alone as opposed to the NOAA or AGAGE measurements of these gases (see Methods), where these gases are reported as a sum of the paired isomers. It was previously assumed that the isomers are co-produced and therefore co-emitted into the atmosphere. However, mole fractions of CFC-112 (CCl2FCCl2F) and CFC-113 (CClF2CCl2F) have been declining continuously since 1996, and those of CFC-114 (CClF2CClF2) have declined, or been indistinguishable from zero growth, since 1998.

Extended Data Fig. 4 Annual global mean emissions.

(a) CFC-112, (b) CFC-112a, (c) CFC-113, (d) CFC-113a, (e) CFC-114, (f) CFC-114a, (g) CFC-13 and (h) CFC-115. Shading shows the 1-sigma standard deviation uncertainty. Emissions are in units of gigagrams by mass of the substance released. CFC-113a emissions have grown fastest, with a 244% increase in emissions between 2010–2020 (2.5 ± 0.4 ODP-Gg yr−1 in 2020). Emissions of CFC-112a increased by 169% over the same period, although the 2020 emissions are modest at 0.10 ± 0.03 ODP-Gg yr−1 in 2020, compared to 0.6 ± 0.07 ODP-Gg yr−1 for CFC-114a, which increased by 108%. Emissions of CFC-115 were at a minimum in 2009–2010 (0.1 ± 0.1 ODP-Gg yr−1), before rapidly rising to 0.5 ± 0.1 ODP-Gg yr−1 in 2017, and slightly falling to 0.4 ± 0.1 ODP-Gg yr−1 in 2020 (2010–2020 increase of 192%). CFC-115 emissions are still substantially smaller than at its peak of around 3 ODP-Gg yr−1 in the late 1980s and early 1990s. CFC-13 emissions in 2019 (0.7 ± 0.1 ODP-Gg yr−1) were at their highest of this millennium (0.5 ± 0.1 ODP-Gg yr−1 in 2010 and 0.7 ± 0.1 ODP-Gg yr−1 in 2020), again contrasting with a rapid decline since its emissions peaked in the 1980s, and representing a 41% increase in emissions between 2010–2020.

Extended Data Fig. 5 Comparison of HFC production and CFC emissions which may be associated with HFC production.

The production of HFC-125 (a) and HFC-134a (b) is shown by the blue shading for Article 5 countries and orange shading for non-Article 5 countries. The composite of these two shading blocks shows total global production (without any metric of uncertainty). The estimates of HFC production assumes that all countries have ratified the Kigali Amendment, which to date would underestimate HFC production, and the values displayed are the mean of the lower and upper estimates from ref. 14. The production quantity is shown on the left axis. Mean global emissions are shown for CFC-115 (pink), CFC-113a (green) and CFC-114a (dark orange) by dotted lines and the shading around the line shows the 1-sigma standard deviation uncertainties in the emissions. The right axis displays the emission values for CFCs by mass. CFC-113a, CFC-114a and CFC-115 are known by-products of HFC-125 production (panel a), and CFC-113a and CFC-114a are a feedstock and intermediate, respectively, in one of the production pathways to HFC-134a (panel b).

Rights and permissions

Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Western, L.M., Vollmer, M.K., Krummel, P.B. et al. Global increase of ozone-depleting chlorofluorocarbons from 2010 to 2020. Nat. Geosci. 16, 309–313 (2023). https://doi.org/10.1038/s41561-023-01147-w

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/s41561-023-01147-w

This article is cited by

Search

Advanced search

Quick links

Nature Briefing Anthropocene

Sign up for the Nature Briefing: Anthropocene newsletter — what matters in anthropocene research, free to your inbox weekly.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing: Anthropocene