Skip to main content

Thank you for visiting 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.

Increased terrestrial methane cycling at the Palaeocene–Eocene thermal maximum


The Palaeocene–Eocene thermal maximum (PETM), a period of intense, global warming about 55 million years ago1, has been attributed to a rapid rise in greenhouse gas levels, with dissociation of methane hydrates being the most commonly invoked explanation2. It has been suggested previously that high-latitude methane emissions from terrestrial environments could have enhanced the warming effect3,4, but direct evidence for an increased methane flux from wetlands is lacking. The Cobham Lignite, a recently characterized expanded lacustrine/mire deposit in England, spans the onset of the PETM5 and therefore provides an opportunity to examine the biogeochemical response of wetland-type ecosystems at that time. Here we report the occurrence of hopanoids, biomarkers derived from bacteria, in the mire sediments from Cobham. We measure a decrease in the carbon isotope values of the hopanoids at the onset of the PETM interval, which suggests an increase in the methanotroph population. We propose that this reflects an increase in methane production potentially driven by changes to a warmer1,6 and wetter climate7,8. Our data suggest that the release of methane from the terrestrial biosphere increased and possibly acted as a positive feedback mechanism to global warming.

Access options

Rent or Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.

Figure 1: Depth profile through the Cobham Lignite.
Figure 2: Gas chromatogram of a typical Cobham Lignite apolar (hydrocarbon) fraction.


  1. 1

    Zachos, J. C. et al. A transient rise in tropical sea surface temperature during the Paleocene–Eocene Thermal Maximum. Science 302, 1551–1554 (2003)

    CAS  Article  ADS  PubMed  Google Scholar 

  2. 2

    Dickens, G. R. Rethinking the global carbon cycle with a large, dynamic and microbially mediated gas hydrate capacitor. Earth Planet. Sci. Lett. 213, 169–183 (2003)

    CAS  Article  ADS  Google Scholar 

  3. 3

    Sloan, L. C., Walker, J. C. G., Moore, T. C., Rea, D. K. & Zachos, J. C. Possible methane-induced polar warming in the early Eocene. Nature 357, 320–322 (1992)

    CAS  Article  ADS  PubMed  Google Scholar 

  4. 4

    Sloan, L. C. & Pollard, D. Polar stratospheric clouds: A high latitude warming mechanism in an ancient greenhouse world. Geophys. Res. Lett. 25, 3517–3520 (1998)

    Article  ADS  Google Scholar 

  5. 5

    Collinson, M. E., Hooker, J. J. & Gröcke, D. R. in Causes and Consequences of Globally Warm Climates in the Early Paleogene (eds Wing, S. L., Gingerich, P. D., Schmitz, B. & Thomas, B.) 333–349 (Geol. Soc. Am. Special Paper 369, Boulder, Colorado, 2003)

    Book  Google Scholar 

  6. 6

    Kennett, J. P. & Stott, L. D. Abrupt deep-sea warming, palaeoceanographic changes and benthic extinctions at the end of the Palaeocene. Nature 353, 225–229 (1991)

    Article  ADS  Google Scholar 

  7. 7

    Bowen, G. J., Beerling, D. J., Koch, P. L., Zachos, J. C. & Quattlebaum, T. A humid climate state during the Palaeocene/Eocene thermal maximum. Nature 432, 495–499 (2004)

    CAS  Article  ADS  PubMed  Google Scholar 

  8. 8

    Crouch, E. M. et al. The Apectodinium acme and terrestrial discharge during the Paleocene–Eocene thermal maximum: new palynological, geochemical and calcareous nannoplankton observations at Tawanui, New Zealand. Palaeogeogr. Palaeoclimatol. Palaeoecol. 194, 387–403 (2003)

    Article  Google Scholar 

  9. 9

    Zachos, J., Pagani, M., Sloan, L., Thomas, E. & Billups, K. Trends, rhythms, and aberrations in global climate 65 Ma to present. Science 292, 686–693 (2001)

    CAS  Article  ADS  PubMed  Google Scholar 

  10. 10

    Collinson, M. E., Steart, D. C., Scott, A. C., Glasspool, I. J. & Hooker, J. J. Episodic fire, run-off and deposition at the Palaeocene–Eocene boundary. J. Geol. Soc. Lond. 164, 87–97 (2007)

    Article  Google Scholar 

  11. 11

    Magioncalda, R. et al. L’excursion isotopique du carbone organique (δ13C) dans les paléoenvironnements continentaux de l’intervalle Paléocène/Eocène de Varengeville (Haute-Normandie). Bull. Soc. Geol. Fr. 172, 349–358 (2001)

    CAS  Article  Google Scholar 

  12. 12

    Steurbaut, E. et al. Palynology, palaeoenvironments, and organic carbon isotope evolution in lagoonal Paleocene–Eocene boundary settings in North Belgium. GSA Spec. Pap. 369, 291–317 (2003)

    Google Scholar 

  13. 13

    Xie, S. C., Pancost, R. D., Yin, H. F., Wang, H. M. & Evershed, R. P. Two episodes of microbial change coupled with Permo/Triassic faunal mass extinction. Nature 434, 494–497 (2005)

    CAS  Article  ADS  PubMed  Google Scholar 

  14. 14

    Eglinton, G. & Hamilton, R. J. Leaf epicuticular waxes. Science 156, 1322–1334 (1967)

    CAS  Article  ADS  PubMed  Google Scholar 

  15. 15

    Rohmer, M., Bouviernave, P. & Ourisson, G. Distribution of hopanoid triterpenes in prokaryotes. J. Gen. Microbiol. 130, 1137–1150 (1984)

    CAS  Google Scholar 

  16. 16

    Hartner, T., Straub, K. L. & Kannenberg, E. Occurrence of hopanoid lipids in anaerobic Geobacter species. FEMS Microbiol. Lett. 243, 59–64 (2005)

    Article  CAS  PubMed  Google Scholar 

  17. 17

    Pancost, R. D., Baas, M., van Geel, B. & Damste, J. S. S. Response of an ombrotrophic bog to a regional climate event revealed by macrofossil, molecular and carbon isotopic data. Holocene 13, 921–932 (2003)

    Article  ADS  Google Scholar 

  18. 18

    Collister, J. W., Summons, R. E., Lichtfouse, E. & Hayes, J. M. An isotopic biogeochemical study of the Green River oil-shale. Org. Geochem. 19, 265–276 (1992)

    CAS  Article  PubMed  Google Scholar 

  19. 19

    Ruble, T. E., Bakel, A. J. & Philp, R. P. Compound-specific isotopic variability in Uinta Basin native bitumens—paleoenvironmental implications. Org. Geochem. 21, 661–671 (1994)

    CAS  Article  Google Scholar 

  20. 20

    Schouten, S. et al. Molecular organic tracers of biogeochemical processes in a saline meromictic lake (Ace Lake). Geochim. Cosmochim. Acta 65, 1629–1640 (2001)

    CAS  Article  ADS  Google Scholar 

  21. 21

    Inubushi, K. et al. Factors influencing methane emission from peat soils: Comparison of tropical and temperate wetlands. Nutrient Cycling Agroecosyst. 71, 93–99 (2005)

    CAS  Article  Google Scholar 

  22. 22

    Christensen, T. R. et al. Factors controlling large scale variations in methane emissions from wetlands. Geophys. Res. Lett. 30 1414 doi: 10.1029/2002GL016848 (2003)

    CAS  Article  ADS  Google Scholar 

  23. 23

    Steart, D. C., Collinson, M. E., Scott, A. C., Glasspool, I. J. & Hooker, J. J. The Cobham Lignite Bed: the palaeobotany of two petrographically contrasting lignites from either side of the Paleocene–Eocene carbon isotope excursion. Acta Palaeobot 47, (1)109–125 (2007)

    Google Scholar 

  24. 24

    Schmitz, B. & Pujalte, V. Abrupt increase in seasonal extreme precipitation at the Paleocene–Eocene boundary. Geology 35, 215–218 (2007)

    CAS  Article  ADS  Google Scholar 

  25. 25

    Gibson, T. G., Bybell, L. M. & Mason, D. B. Stratigraphic and climatic implications of clay mineral changes around the Paleocene/Eocene boundary of the northeastern US margin. Sedim. Geol. 134, 65–92 (2000)

    CAS  Article  ADS  Google Scholar 

  26. 26

    Zachos, J. C. et al. Rapid acidification of the ocean during the Paleocene–Eocene thermal maximum. Science 308, 1611–1615 (2005)

    CAS  Article  ADS  PubMed  Google Scholar 

  27. 27

    Pagani, M. et al. Arctic hydrology during global warming at the Palaeocene/Eocene thermal maximum. Nature 442, 671–675 (2006)

    CAS  Article  ADS  PubMed  Google Scholar 

  28. 28

    Maslin, M. A. & Thomas, E. Balancing the deglacial global carbon budget: the hydrate factor. Quat. Sci. Rev. 22, 1729–1736 (2003)

    Article  ADS  Google Scholar 

  29. 29

    Kurtz, A. C., Kump, L. R., Arthur, M. A., Zachos, J. C. & Paytan, A. Early Cenozoic decoupling of the global carbon and sulfur cycles. Paleoceanography 18, doi:10.1029/2003PA000908. (2003)

    Article  Google Scholar 

  30. 30

    Sluijs, A. et al. Subtropical arctic ocean temperatures during the Palaeocene/Eocene thermal maximum. Nature 441, 610–613 (2006)

    CAS  Article  ADS  PubMed  Google Scholar 

  31. 31

    Gradstein, F. M., Ogg, J. G. & Smith, A. G. (eds) A Geologic Time Scale 2004 (Cambridge University Press, Cambridge, 2004)

    Book  Google Scholar 

  32. 32

    Ellison, R. A., Ali, J. R., Hine, N. M. & Jolley, D. W. in Correlation of the Early Paleogene in Northwest Europe (eds Knox, R. W. O’B., Corfield, R. M. & Dunay, R. E.) 185–193 (Geol. Soc. Lond. Special Publication 101, 1996)

    Google Scholar 

  33. 33

    Bujak, J. P. & Brinkhuis, H. in Late Paleocene–Early Eocene Climatic and Biotic Events in the Marine and Terrestrial Records (eds Aubry, M.-P., Lucas, S. G. & Berggren, W. A.) 277–295 (Columbia University Press, New York, 1998)

    Google Scholar 

  34. 34

    Powell, A. J. in A Stratigraphic Index of Dinoflagellate Cysts (ed. Powell, A. J.) 155–252 (Br. Micropalaeontol. Soc. Publ. Series, Chapman & Hall, London, 1992)

    Book  Google Scholar 

  35. 35

    Grassineau, N. V. High-precision EA-IRMS analysis of S and C isotopes in geological materials. Appl. Geochem. 21, 756–765 (2006)

    CAS  Article  Google Scholar 

Download references


We thank I. D. Bull and R. Berstan of the Bristol Node of the NERC Life Sciences Mass Spectrometry Facility (LSMSF) for analytical support; Alfred McAlpine plc, AMEC and Channel Tunnel Rail Link for access to the Cobham Lignite Bed, and S. Rose for making arrangements; J. Skipper and S. Tracey for help with initial sample collection and field discussions; and L. Kump for critical comments and advice on the ideas proposed here. We acknowledge funding support for this research from the Leverhulme Trust, and studentship support for L.H. from the NERC.

Author Contributions R.D.P. and M.E.C. contributed equally to this paper. M.E.C., J.J.H. and A.C.S. initially characterized the Cobham Lignite, with I.J.G., and led the subsequent more detailed characterization of the sediments and fossils conducted by D.S.S. R.D.P. led the biomarker analyses at Bristol, with most of the preparation and analyses being conducted by D.S.S., with training and assistance from L.H. N.V.G. conducted bulk organic matter isotopic measurements. R.D.P. wrote the paper, and all authors discussed the results and commented on the manuscript.

Author information



Corresponding author

Correspondence to Richard D. Pancost.

Ethics declarations

Competing interests

Reprints and permissions information is available at The authors declare no competing financial interests.

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Pancost, R., Steart, D., Handley, L. et al. Increased terrestrial methane cycling at the Palaeocene–Eocene thermal maximum. Nature 449, 332–335 (2007).

Download citation

Further reading


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.


Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

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