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Long-term decline of global atmospheric ethane concentrations and implications for methane


After methane, ethane is the most abundant hydrocarbon in the remote atmosphere. It is a precursor to tropospheric ozone and it influences the atmosphere’s oxidative capacity through its reaction with the hydroxyl radical, ethane’s primary atmospheric sink1,2,3. Here we present the longest continuous record of global atmospheric ethane levels. We show that global ethane emission rates decreased from 14.3 to 11.3 teragrams per year, or by 21 per cent, from 1984 to 2010. We attribute this to decreasing fugitive emissions from ethane’s fossil fuel source—most probably decreased venting and flaring of natural gas in oil fields—rather than a decline in its other major sources, biofuel use and biomass burning. Ethane’s major emission sources are shared with methane, and recent studies have disagreed on whether reduced fossil fuel or microbial emissions have caused methane’s atmospheric growth rate to slow4,5. Our findings suggest that reduced fugitive fossil fuel emissions account for at least 10–21 teragrams per year (30–70 per cent) of the decrease in methane’s global emissions, significantly contributing to methane’s slowing atmospheric growth rate since the mid-1980s.

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Figure 1: Individual air sampling locations for the UCI global trace gas monitoring network.
Figure 2: Latitudinal distribution of ethane mixing ratios from 1984–2010.
Figure 3: Simulated and observed ethane mixing ratios from 2000 to 2010.
Figure 4: Running global averages of ethane mixing ratios and methane growth rate.


  1. Rudolph, J. The tropospheric distribution and budget of ethane. J. Geophys. Res. 100 (D6). 11369–11381 (1995)

    Article  ADS  CAS  Google Scholar 

  2. Gupta, M. L., Cicerone, R. J., Blake, D. R., Rowland, F. S. & Isaksen, I. S. A. Global atmospheric distributions and source strengths of light hydrocarbons and tetrachloroethene. J. Geophys. Res. 103 (D28). 28219–28235 (1998)

    Article  ADS  CAS  Google Scholar 

  3. Pozzer, A. et al. Observed and simulated global distribution and budget of atmospheric C2-C5 alkanes. Atmos. Chem. Phys. 10, 4403–4422 (2010)

    Article  ADS  CAS  Google Scholar 

  4. Aydin, M. et al. Recent decreases in fossil-fuel emissions of ethane and methane derived from firn air. Nature 476, 198–201 (2011)

    Article  ADS  CAS  Google Scholar 

  5. Kai, F. M., Tyler, S. C., Randerson, J. T. & Blake, D. R. Reduced methane growth rate explained by decreased Northern Hemisphere microbial sources. Nature 476, 194–197 (2011)

    Article  ADS  CAS  Google Scholar 

  6. Stein, O. & Rudolph, J. Modeling and interpretation of stable carbon isotope ratios of ethane in global chemical transport models. J. Geophys. Res. 112, D14308 (2007)

    Article  ADS  Google Scholar 

  7. Xiao, Y. et al. Global budget of ethane and regional constraints on U.S. sources. J. Geophys. Res. 113, D21306 (2008)

    Article  ADS  Google Scholar 

  8. Etiope, G. & Ciccioli, P. Earth’s degassing: a missing ethane and propane source. Science 323, 478 (2009)

    Article  ADS  CAS  Google Scholar 

  9. Blake, D. R. & Rowland, F. S. Global atmospheric concentrations and source strengths of ethane. Nature 321, 231–233 (1986)

    Article  ADS  CAS  Google Scholar 

  10. Simpson, I. J., Rowland, F. S., Meinardi, S. & Blake, D. R. Influence of biomass burning during recent fluctuations in the slow growth of global tropospheric methane. Geophys. Res. Lett. 33, L22808 (2006)

    Article  ADS  Google Scholar 

  11. Rinsland, C. P. et al. Multiyear infrared solar spectroscopic measurements of HCN, CO, C2H6, and C2H2 tropospheric columns above Lauder, New Zealand (45°S latitude). J. Geophys. Res. 107 (D14). 4185 (2002)

    Article  Google Scholar 

  12. Montzka, S. A. et al. Small interannual variability of global atmospheric hydroxyl. Science 331, 67–69 (2011)

    Article  ADS  CAS  Google Scholar 

  13. Elvidge, C. D. et al. A fifteen year record of global natural gas flaring derived from satellite data. Energies 2, 595–622 (2009)

    Article  CAS  Google Scholar 

  14. Johnson, M. R. & Coderre, A. R. An analysis of flaring and venting activity in the Alberta upstream oil and gas industry. J. Air Waste Manage. Assoc. 61, 190–200 (2011)

    Article  CAS  Google Scholar 

  15. Stern, D. I. & Kaufmann, R. K. Estimates of global anthropogenic methane emissions 1860–1993. Chemosphere 33, 159–176 (1996)

    Article  ADS  CAS  Google Scholar 

  16. Dlugokencky, E. J. et al. Atmospheric methane levels off: temporary pause or a new steady-state? Geophys. Res. Lett. 30, 1992 (2003)

    Article  ADS  Google Scholar 

  17. Katzenstein, A. S., Doezema, L. A., Simpson, I. J., Blake, D. R. & Rowland, F. S. Extensive regional atmospheric hydrocarbon pollution in the southwestern United States. Proc. Natl Acad. Sci. USA 100, 11975–11979 (2003)

    Article  ADS  CAS  Google Scholar 

  18. Jones, V. T., Matthews, M. D. & Richers, D. M. Light hydrocarbons for petroleum and gas prospecting. In Geochemical Remote Sensing of the Sub-Surface Vol. 7 Handbook of Exploration Geochemistry (eds Govett, G. J. S. & Hale, M. ) 133–211 (Elsevier, 2000)

    Book  Google Scholar 

  19. Bousquet, P. et al. Contribution of anthropogenic and natural sources to atmospheric methane variability. Nature 443, 439–443 (2006)

    Article  ADS  CAS  Google Scholar 

  20. Levin, I. et al. No inter-hemispheric δ13CH4 trend observed. Nature 486, E3–E4 (2012)

    Article  CAS  Google Scholar 

  21. Schultz, M. G. et al. Global wildland fire emissions from 1960 to 2000. Glob. Biogeochem. Cycles 22, GB2002 (2008)

    Article  ADS  Google Scholar 

  22. van der Werf, G. R. et al. Global fire emissions and the contribution of deforestation, savanna, forest, agricultural, and peat fires (1997–2009). Atmos. Chem. Phys. 10, 11707–11735 (2010)

    Article  ADS  CAS  Google Scholar 

  23. Wiedinmyer, C. et al. The Fire INventory from NCAR (FINN): a high resolution global model to estimate the emissions from open burning. Geosci. Model Dev. 4, 625–641 (2011)

    Article  ADS  Google Scholar 

  24. Fernandes, S. D., Trautmann, N. M., Streets, D. G., Roden, C. A. & Bond, T. C. Global biofuel use, 1850–2000. Glob. Biogeochem. Cycles 21, GB2019 (2007)

    Article  ADS  Google Scholar 

  25. Strąpoć, D., Mastalerz, M., Eble, C. & Schimmelmann, A. Characterization of the origin of coalbed gases in southeastern Illinois Basin by compound-specific carbon and hydrogen stable isotope ratios. Org. Geochem. 38, 267–287 (2007)

    Article  Google Scholar 

  26. Krol, M. C. et al. The two-way nested global chemistry-transport zoom model TM5: algorithm and applications. Atmos. Chem. Phys. 5, 417–432 (2005)

    Article  ADS  CAS  Google Scholar 

  27. Spivakovsky, C. M. et al. Three dimensional climatological distribution of tropospheric OH: update and evaluation. J. Geophys. Res. 105 (D7). 8931–8980 (2000)

    Article  ADS  CAS  Google Scholar 

  28. Sander, S. P. et al. Chemical kinetics and photochemical data for use in atmospheric studies. Evaluation No. 17, JPL Publication No. 10–6, (Jet Propulsion Laboratory, 2011)

  29. Andreae, M. O. & Merlet, P. Emission of trace gases and aerosols from biomass burning. Glob. Biogeochem. Cycles 15, 955–966 (2001)

    Article  ADS  CAS  Google Scholar 

  30. Yevich, R. & Logan, J. A. An assessment of biofuel use and burning of agricultural waste in the developing world. Glob. Biogeochem. Cycles 17, 1095 (2003)

    Article  ADS  Google Scholar 

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This research was funded by NASA (grant NAG5-8935), with contributions from the Gary Comer Abrupt Climate Change Fellowship. We acknowledge discussions with many colleagues, especially M. Aydin and C. Wiedinmyer. We thank colleagues at the Norfolk Island Bureau of Meteorology and the NOAA research stations in Samoa and Barrow for sample collection; the UCI team for sample collection and analysis, especially B. Chisholm, R. Day, G. Liu, B. Love and M. McEachern; and K. Masarie for work with the NOAA/INSTAAR data. M.P.S.A. is supported at JPL by an appointment to the NASA Postdoctoral Program, administered by Oak Ridge Associated Universities through a contract with NASA.

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Authors and Affiliations



I.J.S. was responsible for data quality assurance, global averaging and emission calculations and manuscript preparation. M.P.S.A. prepared the figures and improved the manuscript. S.M. was responsible for sample analysis and calibration, and data quality assurance. L.B. did the ethane modelling. N.J.B. improved the manuscript. D.H. made the NOAA/INSTAAR measurements and improved the manuscript. F.S.R. was responsible for study design and data quality assurance. D.R.B. was responsible for study design and data quality assurance, and improved the manuscript.

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Correspondence to Isobel J. Simpson.

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The authors declare no competing financial interests.

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Simpson, I., Sulbaek Andersen, M., Meinardi, S. et al. Long-term decline of global atmospheric ethane concentrations and implications for methane. Nature 488, 490–494 (2012).

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