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.

Eocene global warming events driven by ventilation of oceanic dissolved organic carbon


‘Hyperthermals’ are intervals of rapid, pronounced global warming known from six episodes within the Palaeocene and Eocene epochs (65–34 million years (Myr) ago)1,2,3,4,5,6,7,8,9,10,11,12,13. The most extreme hyperthermal was the 170 thousand year (kyr) interval2 of 5–7 °C global warming3 during the Palaeocene–Eocene Thermal Maximum (PETM, 56 Myr ago). The PETM is widely attributed to massive release of greenhouse gases from buried sedimentary carbon reservoirs1,3,6,11,14,15,16,17, and other, comparatively modest, hyperthermals have also been linked to the release of sedimentary carbon3,6,11,16,17. Here we show, using new 2.4-Myr-long Eocene deep ocean records, that the comparatively modest hyperthermals are much more numerous than previously documented, paced by the eccentricity of Earth’s orbit and have shorter durations (40 kyr) and more rapid recovery phases than the PETM. These findings point to the operation of fundamentally different forcing and feedback mechanisms than for the PETM, involving redistribution of carbon among Earth’s readily exchangeable surface reservoirs rather than carbon exhumation from, and subsequent burial back into, the sedimentary reservoir. Specifically, we interpret our records to indicate repeated, large-scale releases of dissolved organic carbon (at least 1,600 gigatonnes) from the ocean by ventilation (strengthened oxidation) of the ocean interior. The rapid recovery of the carbon cycle following each Eocene hyperthermal strongly suggests that carbon was re-sequestered by the ocean, rather than the much slower process of silicate rock weathering proposed for the PETM1,3. Our findings suggest that these pronounced climate warming events were driven not by repeated releases of carbon from buried sedimentary sources3,6,11,16,17, but, rather, by patterns of surficial carbon redistribution familiar from younger intervals of Earth history.

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

Relevant articles

Open Access articles citing this article.

Access options

Rent or buy this article

Get just this article for as long as you need it


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

Figure 1: High-resolution records across the early Eocene to middle Eocene transition from ODP Site 1258, Demerara rise, tropical Atlantic.
Figure 2: Details of stable isotope data from ODP Site 1258 across two ‘hyperthermal’ events.
Figure 3: Eocene records of benthic foraminifer δ 13 C and CaCO 3 dissolution.


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

    Article  CAS  ADS  Google Scholar 

  2. Röhl, U., Westerhold, T., Bralower, T. J. & Zachos, J. C. On the duration of the Paleocene-Eocene thermal maximum (PETM). Geochem. Geophys. Geosyst. 8, Q12002 (2007)

    Article  ADS  Google Scholar 

  3. Zachos, J. C., Dickens, G. R. & Zeebe, R. E. An early Cenozoic perspective on greenhouse warming and carbon-cycle dynamics. Nature 451, 279–283 (2008)

    Article  CAS  ADS  Google Scholar 

  4. Thomas, E., Zachos, J. C. & Bralower, T. J. in Warm Climates in Earth History (eds Huber, B., MacLeod, K. & Wing, S. ) 132–160 (Cambridge Univ. Press, 2000)

    Google Scholar 

  5. Cramer, B. S., Wright, J. D., Kent, D. V. & Aubry, M. P. Orbital climate forcing of δ13C excursions in the late Paleocene-early Eocene (chrons C24n-C25n). Paleoceanography 18 1097 10.1029/2003PA000909 (2003)

    Article  ADS  Google Scholar 

  6. Lourens, L. J. et al. Astronomical pacing of late Palaeocene to early Eocene global warming events. Nature 435, 1083–1087 (2005)

    Article  CAS  ADS  Google Scholar 

  7. Petrizzo, M. R. An early late Paleocene event on Shatsky Rise, northwest Pacific Ocean (ODP Leg 198): evidence from planktonic foraminiferal assemblages. Proc. ODP Sci. Res. 198, 1–29 (2005)

    Google Scholar 

  8. Sexton, P. F., Wilson, P. A. & Norris, R. D. Testing the Cenozoic multisite composite δ18O and δ13C curves: new monospecific Eocene records from a single locality, Demerara Rise (Ocean Drilling Program Leg 207). Paleoceanography 21 PA2019 10.1029/2005PA001253 (2006)

    Article  ADS  Google Scholar 

  9. Westerhold, T. et al. On the duration of magnetochrons C24r and C25n and the timing of early Eocene global warming events: implications from the Ocean Drilling Program Leg 208 Walvis Ridge depth transect. Paleoceanography 22 PA2201 10.1029/2006PA001322 (2007)

    Article  ADS  Google Scholar 

  10. Edgar, K. M., Wilson, P. A., Sexton, P. F. & Suganuma, Y. No extreme bipolar glaciation during the main Eocene calcite compensation shift. Nature 448, 908–911 (2007)

    Article  CAS  ADS  Google Scholar 

  11. Nicolo, M. J., Dickens, G. R., Hollis, C. J. & Zachos, J. C. Multiple early Eocene hyperthermals: their sedimentary expression on the New Zealand continental margin and in the deep sea. Geology 35, 699–702 (2007)

    Article  CAS  ADS  Google Scholar 

  12. Quillévéré, F., Norris, R. D., Kroon, D. & Wilson, P. A. Transient ocean warming and shifts in carbon reservoirs during the early Danian. Earth Planet. Sci. Lett. 265, 600–615 (2008)

    Article  ADS  Google Scholar 

  13. Stap, L. et al. High-resolution deep-sea carbon and oxygen isotope records of Eocene Thermal Maximum 2 and H2. Geology 38, 607–610 (2010)

    Article  CAS  ADS  Google Scholar 

  14. Dickens, G. R., O’Neil, J. R., Rea, D. K. & Owen, R. M. Dissociation of oceanic methane hydrate as a cause of the carbon isotope excursion at the end of the Paleocene. Paleoceanography 10, 965–971 (1995)

    Article  ADS  Google Scholar 

  15. Dickens, G. R. Methane oxidation during the late Palaeocene thermal maximum. Bull. Soc. Geol. Fr. 171, 37–49 (2000)

    CAS  Google Scholar 

  16. 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)

    Article  CAS  ADS  Google Scholar 

  17. Panchuk, K., Ridgwell, A. & Kump, L. R. Sedimentary response to Paleocene-Eocene Thermal Maximum carbon release: a model-data comparison. Geology 36, 315–318 (2008)

    Article  CAS  ADS  Google Scholar 

  18. Archer, D. Fate of fossil fuel CO2 in geologic time. J. Geophys. Res 110 C09S05 10.1029/2004JC002625 (2005)

    Article  CAS  ADS  Google Scholar 

  19. Hodell, D. A., Venz, K. A., Charles, C. D. & Ninnemann, U. S. Pleistocene vertical carbon isotope and carbonate gradients in the South Atlantic sector of the Southern Ocean. Geochem. Geophys. Geosyst. 4 (1). 1004 10.1029/2002GC000367 (2003)

    Article  ADS  Google Scholar 

  20. Toggweiler, J. R., Russell, J. L. & Carson, S. R. Midlatitude westerlies, atmospheric CO2, and climate change during the ice ages. Paleoceanography 21 PA2005 10.1029/2005PA001154 (2006)

    Article  ADS  Google Scholar 

  21. Skinner, L. C., Fallon, S., Waelbroeck, C., Michel, E. & Barker, S. Ventilation of the deep Southern Ocean and deglacial CO2 rise. Science 328, 1147–1151 (2010)

    Article  CAS  ADS  Google Scholar 

  22. Sigman, D. M., de Boer, A. M. & Haug, G. H. in Past and Future Changes of the Oceanic Meridional Overturning Circulation: Mechanisms and Impacts (eds Schmittner, A., J., Chiang, H. C. & Hemming, S. R. ) 335–350 (AGU Geophysical Monograph 173, American Geophysical Union, 2007)

    Book  Google Scholar 

  23. Marchitto, T. M., Lehman, S. J., Ortiz, J. D., Fluckiger, J. & van Geen, A. Marine radiocarbon evidence for the mechanism of deglacial atmospheric CO2 rise. Science 316, 1456–1459 (2007)

    Article  CAS  ADS  Google Scholar 

  24. Hansell, D. A. & Carlson, C. A. Deep-ocean gradients in the concentration of dissolved organic carbon. Nature 395, 263–266 (1998)

    Article  CAS  ADS  Google Scholar 

  25. Ducklow, H. W., Hansell, D. A. & Morgan, J. A. Dissolved organic carbon and nitrogen in the western Black Sea. Mar. Chem. 105, 140–150 (2007)

    Article  CAS  Google Scholar 

  26. 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 1090 10.1029/2003PA000908 (2003)

    Article  ADS  Google Scholar 

  27. Schmittner, A., Oschlies, A., Matthews, H. D. & Galbraith, E. D. Future changes in climate, ocean circulation, ecosystems, and biogeochemical cycling simulated for a business-as-usual CO2 emission scenario until year 4000 AD. Glob. Biogeochem. Cycles 22 GB1013 10.1029/2007GB002953 (2008)

    Article  CAS  ADS  Google Scholar 

  28. Falkowski, P. G. et al. The evolution of modern eukaryotic phytoplankton. Science 305, 354–360 (2004)

    Article  CAS  ADS  Google Scholar 

  29. Klaas, C. & Archer, D. E. Association of sinking organic matter with various types of mineral ballast in the deep sea: implications for the rain ratio. Glob. Biogeochem. Cycles 16 (4). 1116 10.1029/2001GB001765 (2002)

    Article  CAS  ADS  Google Scholar 

  30. Buffett, B. & Archer, D. Global inventory of methane clathrate: sensitivity to changes in the deep ocean. Earth Planet. Sci. Lett. 227, 185–199 (2004)

    Article  CAS  ADS  Google Scholar 

  31. Curry, W. B., Slowey, N. C. & Lohmann, G. P. Oxygen and carbon isotopic fractionation of aragonitic and calcitic benthic foraminifera on Little Bahama Bank, Bahamas. Eos 74, 368 (1993)

    Google Scholar 

  32. Tjalsma, R. C. & Lohmann, G. P. Paleocene-Eocene Bathyal and Abyssal Benthic Foraminifera from the Atlantic Ocean (Micropaleontol. Spec. Publ. Ser., Vol. 4, Micropaleontol. Proj., New York, 1983)

    Google Scholar 

  33. van Morkhoven, F. P. C. M., Berggren, W. A. & Edwards, A. S. Cenozoic cosmopolitan deep water benthic foraminifera. Bull. Cent. Rech. Explor. Prod. Elf-Aquitaine 11, (Pau, France, 1986)

    Google Scholar 

  34. Katz, M. E. et al. Early Cenozoic benthic foraminiferal isotopes: species reliability and interspecies correction factors. Paleoceanography 18 1024 10.1029/2002PA000798 (2003)

    Article  ADS  Google Scholar 

  35. Bemis, B. E., Spero, H. J., Bijma, J. & Lea, D. W. Reevaluation of the oxygen isotopic composition of planktonic foraminifera: experimental results and revised paleotemperature equations. Paleoceanography 13, 150–160 (1998)

    Article  ADS  Google Scholar 

  36. 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)

    Article  CAS  ADS  Google Scholar 

  37. Browning, J. V., Miller, K. G. & Pak, D. K. Global implications of lower to middle Eocene sequence boundaries on the New Jersey coastal plain: the icehouse cometh. Geology 24, 639–642 (1996)

    Article  CAS  ADS  Google Scholar 

  38. Shipboard Scientific Party, 2004 Site 1258. Proc. ODP Init. Rep. 207. 1–117 10.2973/ (2004)

    Article  Google Scholar 

  39. Suganuma, Y. & Ogg, J. G. Campanian through Eocene magnetostratigraphy of Sites 1257–1261, ODP Leg 207, Demerara Rise (western equatorial Atlantic). Proc. ODP Sci. Res. 207. (2006) available at 〈〉.

  40. Westerhold, T. & Röhl, U. High resolution cyclostratigraphy of the early Eocene — new insights into the origin of the Cenozoic cooling trend. Clim. Past 5, 309–327 (2009)

    Article  Google Scholar 

  41. Laskar, J. et al. A long-term numerical solution for the insolation quantities of the Earth. Astron. Astrophys. 428, 261–285 (2004)

    Article  ADS  Google Scholar 

  42. Berggren, W., Kent, D. & Swisher, C., III in Geochronology Time Scales and Global Stratigraphic Correlation (ed. Berggren, W. ) 129–212 (Society for Sedimentary Geology, Tulsa, 1995)

    Book  Google Scholar 

  43. Machlus, M., Hemming, S. R., Olsen, P. E. & Christie-Blick, N. Eocene calibration of geomagnetic polarity time scale reevaluated: evidence from the Green River Formation of Wyoming. Geology 32, 137–140 (2004)

    Article  ADS  Google Scholar 

  44. Shipboard Scientific Party, 2004 Site 1267. Proc. ODP Init. Rep. 208. 1–77 10.2973/ (2004)

    Article  Google Scholar 

  45. Shipboard Scientific Party, 2002 Site 1210. Proc. ODP Init. Rep. 198. 1–89 10.2973/ (2002)

Download references


We thank M. Bolshaw for laboratory assistance and the shipboard party and crew of Ocean Drilling Program (ODP) Leg 207 for a successful drilling expedition. We thank H. Brinkhuis, G. Dickens, G. Foster, M. Huber, S. Kirtland, D. Kroon, L. Kump, E. Rohling and J. Zachos for discussions. This research used samples and data provided by the ODP. ODP (now IODP) is sponsored by the US NSF and participating countries under the management of JOI, Inc. We thank W. Hale and A. Wülbers (IODP) for assistance with sediment core sampling. Financial support for this research was provided by a European Commission Marie Curie Outgoing International Fellowship (P.F.S.), a Leverhulme Trust Fellowship (P.F.S.), a Natural Environment Research Council UK ODP grant (P.A.W. and P.F.S.), a Philip Leverhulme Prize (H.P.), the DFG-Leibniz Center for Surface Process and Climate Studies at the University of Potsdam, and the DFG (U.R. and T.W.).

Author information

Authors and Affiliations



P.F.S. and P.A.W. designed and instigated the research. P.F.S. and C.T.B. picked foraminifera. P.F.S. and P.A.W. generated stable isotope records. P.F.S. and H.P. generated the estimated CaCO3 content records and constructed age models. P.F.S. conducted stratigraphic correlations between the various drill sites. T.W. and U.R. modified the spliced sedimentary section at Demerara rise. S.G. generated biostratigraphic data for Demerara rise. P.F.S. and R.D.N. wrote the manuscript. P.A.W., H.P., T.W. and U.R. commented on the manuscript.

Corresponding author

Correspondence to Philip F. Sexton.

Ethics declarations

Competing interests

The authors declare no competing financial interests.

Supplementary information

Supplementary Information

The file contains a Supplementary Discussion, Supplementary Figures 1-4 with legends, Supplementary Tables 1-3 and additional references. (PDF 1095 kb)

PowerPoint slides

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Sexton, P., Norris, R., Wilson, P. et al. Eocene global warming events driven by ventilation of oceanic dissolved organic carbon. Nature 471, 349–352 (2011).

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI:

This article is cited by


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