Letter | Published:

Contribution of anthropogenic and natural sources to atmospheric methane variability

Nature volume 443, pages 439443 (28 September 2006) | Download Citation

Subjects

Abstract

Methane is an important greenhouse gas, and its atmospheric concentration has nearly tripled since pre-industrial times1. The growth rate of atmospheric methane is determined by the balance between surface emissions and photochemical destruction by the hydroxyl radical, the major atmospheric oxidant. Remarkably, this growth rate has decreased2 markedly since the early 1990s, and the level of methane has remained relatively constant since 1999, leading to a downward revision of its projected influence on global temperatures. Large fluctuations in the growth rate of atmospheric methane are also observed from one year to the next2, but their causes remain uncertain2,3,4,5,6,7,8,9,10,11,12,13. Here we quantify the processes that controlled variations in methane emissions between 1984 and 2003 using an inversion model of atmospheric transport and chemistry. Our results indicate that wetland emissions dominated the inter-annual variability of methane sources, whereas fire emissions played a smaller role, except during the 1997–1998 El Niño event. These top-down estimates of changes in wetland and fire emissions are in good agreement with independent estimates based on remote sensing information and biogeochemical models. On longer timescales, our results show that the decrease in atmospheric methane growth during the 1990s was caused by a decline in anthropogenic emissions. Since 1999, however, they indicate that anthropogenic emissions of methane have risen again. The effect of this increase on the growth rate of atmospheric methane has been masked by a coincident decrease in wetland emissions, but atmospheric methane levels may increase in the near future if wetland emissions return to their mean 1990s levels.

Access optionsAccess options

Rent or Buy article

Get time limited or full article access on ReadCube.

from$8.99

All prices are NET prices.

References

  1. 1.

    . Climate Change 2001: The Scientific Basis. Contribution of Working Group I to the Third Assessment Report of the Intergovernmental Panel on Climate Change (eds Houghton, J. T. et al.) (Cambridge Univ. Press, Cambridge and New York, 2001)

  2. 2.

    et al. Atmospheric methane levels off: temporary pause or a new steady-state? Geophys. Res. Lett. 30, 1992, doi:10.1029/2003GL018126 (2003)

  3. 3.

    et al. Interannual variability and trend of CH4 lifetime as a measure for OH changes in the 1979–1993 time period. J. Geophys. Res. 108, 4442, doi:10.1029/2002JD002916 (2003)

  4. 4.

    et al. Changes in CH4 and CO growth rates after the eruption of Mt Pinatubo and their link with changes in tropical tropospheric UV flux. Geophys. Res. Lett. 23, 2761–2764 (1996)

  5. 5.

    et al. A dramatic decrease in the growth-rate of atmospheric methane in the Northern-Hemisphere during 1992. Geophys. Res. Lett. 21, 507–507 (1994)

  6. 6.

    et al. Interannual growth rate variations of atmospheric CO2 and its δ C-13, H-2, CH4, and CO between 1992 and 1999 linked to biomass burning. Glob. Biogeochem. Cycles 16, 1048, doi:10.1029/2001GB001466 (2002)

  7. 7.

    , , , & Short-term variations in the oxidizing power of the atmosphere. Nature 436, 1001–1004 (2005)

  8. 8.

    et al. The amount of carbon released from peat and forest fires in Indonesia during 1997. Nature 420, 61–65 (2002)

  9. 9.

    et al. Continental-scale partitioning of fire emissions during the 1997 to 2001 El Niño/La Niña period. Science 303, 73–76 (2004)

  10. 10.

    , & Modeling modern methane emissions from natural wetlands 2. Interannual variations 1982–1993. J. Geophys. Res. 106, 34207–34219 (2001)

  11. 11.

    et al. A 3-D model analysis of the slowdown and interannual variability in the methane growth rate from 1988 to 1997. Glob. Biogeochem. Cycles 18, 3011, doi:10.1029/2003GB002180 (2004)

  12. 12.

    , , , & The impact of meteorology on the interannual growth rate of atmospheric methane. Geophys. Res. Lett. 29, 1947, doi:10.1029/2002GLO15282 (2002)

  13. 13.

    & Estimation of atmospheric methane emissions between 1996 and 2001 using a three-dimensional global chemical transport model. J. Geophys. Res. 111, doi:10.1029/2005JD006058 (2006)

  14. 14.

    , , , & CH4 sources estimated from atmospheric observations of CH4 and its C-13/C-12 isotopic ratios: 1. Inverse modeling of source processes. Glob. Biogeochem. Cycles 18, GB4004, doi:10.1029/2004GB002223 (2004)

  15. 15.

    et al. A burning question. Can recent growth rate anomalies in the greenhouse gases be attributed to large-scale biomass burning events? Atmos. Environ. 39, 2513–2517 (2005)

  16. 16.

    , , & Simultaneous mass balance inverse modeling of methane and carbon monoxide. J. Geophys. Res. 110, D21310, doi:10.1029/2005JD006071 (2005)

  17. 17.

    et al. Interactive chemistry in the Laboratoire de Meteorologie Dynamique general circulation model: description and background tropospheric chemistry evaluation. J. Geophys. Res. 109, D04314, doi:10.1029/2003JD003957 (2004)

  18. 18.

    et al. The ERA-40 reanalysis. Q. J. R. Meteorol. Soc. 131, 2961–3012 (2005)

  19. 19.

    , , , & Two decades of OH variability as inferred by an inversion of atmospheric transport and chemistry of methyl chloroform. Atmos. Chem. Phys. 5, 2635–2656 (2005)

  20. 20.

    et al. Regional changes in carbon dioxide fluxes of land and oceans since 1980. Science 290, 1342–1346 (2000)

  21. 21.

    , , & CO2 flux history 1982–2001 inferred from atmospheric data using a global inversion of atmospheric transport. Atmos. Chem. Phys. 3, 1919–1964 (2003)

  22. 22.

    , , & Methane emissions from terrestrial plants under aerobic conditions. Nature 439, 187–191 (2006)

  23. 23.

    , , & Remote sensing of global wetland dynamics with multiple satellite data sets. Geophys. Res. Lett. 28, 4631–4634, doi:10.1029/2001GL013263 (2001)

  24. 24.

    & The perfect ocean for drought. Science 299, 691–694 (2003)

  25. 25.

    , , & Global surface air temperature in 1995: return to pre-Pinatubo level. Geophys. Res. Lett. 23, 1665–1668 (1996)

  26. 26.

    , , & The growth-rate and distribution of atmospheric methane. J. Geophys. Res. 99, 17021–17043 (1994)

  27. 27.

    et al. Inverse modelling of national and European CH4 emissions using the atmospheric zoom model TM5. Atmos. Chem. Phys. 5, 2431–2460 (2005)

  28. 28.

    et al. Towards robust regional estimates of CO2 sources and sinks using atmospheric transport models. Nature 415, 626–630 (2002)

  29. 29.

    GLOBALVIEW-CH4. Cooperative Atmospheric Data Integration Project—Methane CD-ROM (NOAA/CMDL, Boulder, CO, 2005).

  30. 30.

    et al. Development of analytical methods and measurements of C-13/C-12 in atmospheric CH4 from the NOAA Climate Monitoring and Diagnostics Laboratory global air sampling network. J. Geophys. Res. 107, 4178, doi:10.1029/2001JD000630 (2002)

  31. 31.

    et al. The isotopic composition of atmospheric methane. Glob. Biogeochem. Cycles 13, 445–461 (1999)

  32. 32.

    et al. Stable carbon isotopic composition of atmospheric methane: a comparison of surface level and free tropospheric air. J. Geophys. Res. 104, 13895–13910 (1999)

  33. 33.

    , & An inverse modeling approach to investigate the global atmospheric methane cycle. Glob. Biogeochem. Cycles 11, 43–76 (1997)

Download references

Acknowledgements

We thank P. Rayner, F. Chevallier and F.-M. Breon for comments on the manuscript, and P. Quay for published δ13C-CH4 measurements for the period 1989–1995. Atmospheric CH4 measurements from Réseau Aatmosphérique de Mesure des Composés à Effet de Serre (RAMCES) at Laboratoire des Sciences du Climat et de l'Environnement (LSCE) were partly funded by Institut National des Sciences de l'Univers (INSU). All calculations were realized with Commisariat à l'Energie Atomique (CEA), Centre National de la Recherche Scientifique (CNRS), Institut Pierre Simon Laplace (IPSL) and LSCE computers and support. The development of the Global Fire Emissions Dataset (GFED) used here was supported by a grant from the National Aeronautics and Space Administration (NASA). Author Contributions The main contributions of each author are: P.B.: inversions, data analysis and coordination. P.C.: inverse method and manuscript improvements. J.B.M.: CH4 and δ13C-CH4 data analysis and inversion analysis. E.J.D.: CH4 measurements and manuscript improvements. D.A.H.: chemistry-transport model and manuscript improvements. C.P and F.P.: satellite retrievals of flooded areas. G.R.V.d.W.: CH4 emissions from fires. P.P. and C.C.: inversion method. R.L.L.: CH4 measurements and manuscript improvements. E.G.B., M.R., M.S., L.P.S. and S.C.T.: CH4 measurements. J.L.: plant source analysis. J.W.: δ13C-CH4 measurements.

Author information

Affiliations

  1. Laboratoire des Sciences du Climat et de l'Environnement, IPSL-LSCE, CEA-CNRS-UVSQ, F-91191, France

    • P. Bousquet
    • , P. Ciais
    • , D. A. Hauglustaine
    • , C. Carouge
    • , J. Lathière
    • , M. Ramonet
    •  & M. Schmidt
  2. Université de Versailles Saint Quentin en Yvelines, F-78035, France

    • P. Bousquet
  3. NOAA Earth System Research Laboratory, Global Monitoring Division, Boulder, Colorado 80305-3328, USA

    • J. B. Miller
    •  & E. J. Dlugokencky
  4. Cooperative Institute for Research in Environmental Science, Campus Box 216, University of Colorado, Boulder, Colorado 80309, USA

    • J. B. Miller
  5. LERMA, Observatoire de Paris, F-75014, France

    • C. Prigent
    •  & F. Papa
  6. Faculty of Earth and Life Sciences, Vrije Universiteit, Amsterdam, The Netherlands

    • G. R. Van der Werf
  7. Laboratoire de Biogéochimie Isotopique, LBI, F-78026, France

    • P. Peylin
  8. South African Weather Service, Stellenbosch 7599, South Africa

    • E.-G. Brunke
  9. CSIRO, Marine and Atmospheric Research, Victoria 3195, Australia

    • R. L. Langenfelds
    •  & L. P. Steele
  10. NASA-GISS-Columbia University, New York, New York 10025, USA

    • F. Papa
  11. Earth System Science Department, University of California, Irvine, California 92697, USA

    • S. C. Tyler
  12. Institute of Arctic and Alpine Research, University of Colorado, Boulder, Colorado 80309, USA

    • J. White

Authors

  1. Search for P. Bousquet in:

  2. Search for P. Ciais in:

  3. Search for J. B. Miller in:

  4. Search for E. J. Dlugokencky in:

  5. Search for D. A. Hauglustaine in:

  6. Search for C. Prigent in:

  7. Search for G. R. Van der Werf in:

  8. Search for P. Peylin in:

  9. Search for E.-G. Brunke in:

  10. Search for C. Carouge in:

  11. Search for R. L. Langenfelds in:

  12. Search for J. Lathière in:

  13. Search for F. Papa in:

  14. Search for M. Ramonet in:

  15. Search for M. Schmidt in:

  16. Search for L. P. Steele in:

  17. Search for S. C. Tyler in:

  18. Search for J. White in:

Competing interests

Reprints and permissions information is available at www.nature.com/reprints. The authors declare no competing financial interests.

Corresponding author

Correspondence to P. Bousquet.

Supplementary information

Word documents

  1. 1.

    Supplementary Notes

    This file contains Supplementary Methods, Supplementary Tables and low-resolution versions of the Supplementary Figures.

Image files

  1. 1.

    Supplementary Figure 1

    Map of the regions and the air sampling sites used in the 18 inversions.

  2. 2.

    Supplementary Figure 2

    Fit of the inverse model to the observations

  3. 3.

    Supplementary Figure 3

    Sensitivity of inferred emissions to OH radicals and to possible additional emissions due to plants.

About this article

Publication history

Received

Accepted

Published

DOI

https://doi.org/10.1038/nature05132

Further reading

Comments

By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.