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.

Atmospheric carbon dioxide through the Eocene–Oligocene climate transition

Abstract

Geological and geochemical evidence1,2,3 indicates that the Antarctic ice sheet formed during the Eocene–Oligocene transition4, 33.5–34.0 million years ago. Modelling studies5,6 suggest that such ice-sheet formation might have been triggered when atmospheric carbon dioxide levels () fell below a critical threshold of 750 p.p.m.v., but the timing and magnitude of relative to the evolution of the ice sheet has remained unclear. Here we use the boron isotope pH proxy7,8 on exceptionally well-preserved carbonate microfossils from a recently discovered geological section in Tanzania9,10 to estimate before, during and after the climate transition. Our data suggest that a reduction in occurred before the main phase of ice growth, followed by a sharp recovery to pre-transition values and then a more gradual decline. During maximum ice-sheet growth, was between 450 and 1,500 p.p.m.v., with a central estimate of 760 p.p.m.v. The ice cap survived the period of recovery, although possibly with some reduction in its volume, implying (as models predict11) a nonlinear response to climate forcing during melting. Overall, our results confirm the central role of declining in the development of the Antarctic ice sheet (in broad agreement with carbon cycle modelling12) and help to constrain mechanisms and feedbacks associated with the Earth’s biggest climate switch of the past 65 Myr.

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

Access options

Rent or buy this article

Prices vary by article type

from$1.95

to$39.95

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

Figure 1: Deep-sea oxygen isotope records across the EOT compared with boron isotopes from Tanzania.
Figure 2: Sensitivity of pH and atmospheric carbon dioxide estimates to δ11B for sea water, with modelled atmospheric p CO 2 thresholds for ice growth.
Figure 3: Reconstructed compared with the deep-sea benthic foraminiferal stable isotope record.

Similar content being viewed by others

References

  1. Kennett, J. P. & Shackleton, N. J. Oxygen isotopic evidence for the initiation of the psychrosphere 38 Myr ago. Nature 260, 513–515 (1976)

    Article  ADS  CAS  Google Scholar 

  2. Barrett, P. in Developments in Earth and Environmental Sciences (eds Florindo, F. & Siegert, M.) Vol. 8 34–83 (Elsevier, 2009)

    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  ADS  CAS  Google Scholar 

  4. Coxall, H. K. & Pearson, P. N. in Deep-time Perspectives on Climate Change: Marrying the Signal from Computer Models and Biological Proxies (eds Williams, M. et al.) 351–387 (The Micropalaeontological Society, Special Publications, The Geological Society, London, 2007)

    Book  Google Scholar 

  5. Deconto, R. M. & Pollard, D. Rapid Cenozoic glaciation of Antarctica triggered by declining atmospheric CO2 . Nature 421, 245–249 (2003)

    Article  ADS  CAS  Google Scholar 

  6. Deconto, R. M. et al. Thresholds for Cenozoic bipolar glaciation. Nature 455, 652–656 (2008)

    Article  ADS  CAS  Google Scholar 

  7. Hemming, N. G. & Hanson, G. N. Boron isotope composition and concentration in modern marine carbonates. Geochim. Cosmochim. Acta 59, 371–379 (1992)

    Article  ADS  Google Scholar 

  8. Foster, G. L. Seawater pH, pCO2 and [CO3 2-] variations in the Caribbean Sea over the last 130 kyr: a boron isotope and B/Ca study of planktic foraminifera. Earth Planet. Sci. Lett. 271, 254–266 (2008)

    Article  ADS  CAS  Google Scholar 

  9. Nicholas, C. J. et al. Stratigraphy and sedimentology of the Upper Cretaceous to Paleogene Kilwa Group, southern coastal Tanzania. J. Afr. Earth Sci. 45, 431–466 (2006)

    Article  ADS  Google Scholar 

  10. Pearson, P. N. et al. Extinction and environmental change across the Eocene–Oligocene boundary in Tanzania. Geology 36, 179–182 (2008)

    Article  ADS  CAS  Google Scholar 

  11. Pollard, D. & Deconto, R. M. Hysteresis in Cenozoic Antarctic ice-sheet variations. Global Planet. Change 45, 9–21 (2005)

    Article  ADS  Google Scholar 

  12. Merico, A., Tyrell, T. & Wilson, P. A. Eocene/Oligocene ocean de-acidification linked to Antarctic sea-level fall. Nature 452, 979–983 (2008)

    Article  ADS  CAS  Google Scholar 

  13. Zachos, J. C., Quinn, T. M. & Salamy, K. A. High resolution (104 years) deep-sea foraminiferal stable isotope records of the Eocene–Oligocene climate transition. Paleoceanography 11, 251–256 (1996)

    Article  ADS  Google Scholar 

  14. Coxall, H. K., Wilson, P. A., Pälike, H., Lear, C. H. & Backman, J. Rapid stepwise onset of Antarctic glaciation and deeper calcite compensation in the Pacific Ocean. Nature 433, 53–57 (2003)

    Article  ADS  Google Scholar 

  15. Lear, C. H., Bailey, T. R., Pearson, P. N., Coxall, H. K. & Rosenthal, Y. Cooling and ice growth across the Eocene–Oligocene transition. Geology 36, 251–254 (2008)

    Article  ADS  CAS  Google Scholar 

  16. Katz, M. E. et al. Stepwise transition from the Eocene greenhouse to the Oligocene icehouse. Nature Geosci. 1, 329–334 (2008)

    Article  ADS  CAS  Google Scholar 

  17. Pälike, H. et al. The heartbeat of the Oligocene climate system. Science 314, 1894–1898 (2006)

    Article  ADS  Google Scholar 

  18. Eldrett, J. S., Greenwood, D. R., Harding, I. C. & Huber, M. Increased seasonality through the Eocene to Oligocene transition in northern high latitudes. Nature 459, 969–974 (2009)

    Article  ADS  CAS  Google Scholar 

  19. Hansen, J. et al. Target atmospheric CO2: Where should humanity aim? Open Atmos. Sci. J. 2, 217–231 (2008)

    Article  ADS  CAS  Google Scholar 

  20. Pagani, M., Zachos, J. C., Freeman, K. H., Tipple, B. & Bohaty, S. M. Marked decline in atmospheric carbon dioxide concentrations during the Paleogene. Science 309, 600–603 (2005)

    Article  ADS  CAS  Google Scholar 

  21. Lemarchand, D., Gaillardet, J., Lewin, É. & Allègre, C. J. Boron isotope systematics in large rivers: implications for the marine boron budget and paleo-pH reconstruction over the Cenozoic. Chem. Geol. 190, 123–140 (2002)

    Article  ADS  CAS  Google Scholar 

  22. Simon, L., Lecuyer, C., Marechal, C. & Coltice, N. Modelling the geochemical cycle of boron: implications for the long-term δ11B evolution of seawater and oceanic crust. Chem. Geol. 225, 61–76 (2006)

    Article  ADS  CAS  Google Scholar 

  23. Rea, D. K. & Lyle, M. W. Paleogene calcite compensation depth in the eastern subtropical Pacific: answers and questions. Paleoceanography 20 PA1012 10.1029/2004PA001064 (2005)

    Article  ADS  Google Scholar 

  24. Wade, B. S. & Pearson, P. N. Planktonic foraminiferal turnover, diversity fluctuations and geochemical signals across the Eocene/Oligocene boundary in Tanzania. Mar. Micropal. 68, 244–255 (2008)

    Article  Google Scholar 

  25. Liu, Z. et al. Global cooling during the Eocene–Oligocene climate transition. Science 323, 1187–1190 (2009)

    Article  ADS  CAS  Google Scholar 

  26. Bo, S. et al. The Gamburtsev mountains and the origin and early evolution of the Antarctic ice sheet. Nature 459, 690–693 (2009)

    Article  ADS  Google Scholar 

  27. Salamy, K. A. & Zachos, J. C. Latest Eocene–early Oligocene climate change and Southern Ocean fertility: inferences from sediment accumulation and stable isotope data. Palaeogeogr. Palaeoclimatol. Palaeoecol. 145, 61–77 (1999)

    Article  Google Scholar 

  28. Zachos, J. C. & Kump, L. R. Carbon cycle feedbacks and the initiation of Antarctic glaciation in the earliest Oligocene. Glob. Planet. Change 47, 51–66 (2005)

    Article  ADS  Google Scholar 

  29. Cande, S. C. & Kent, D. V. Revised calibration of the geomagnetic polarity timescale for the Late Cretaceous and Cenozoic. J. Geophys. Res. 100, 6093–6095 (1995)

    Article  ADS  Google Scholar 

  30. Key, R. M. et al. A global ocean carbon climatology: results from Global Data Analysis Project (GLODAP). Glob. Biogeochem. Cycles 18 GB4031 10.1029/2004GB002247 (2004)

    Article  ADS  CAS  Google Scholar 

  31. Barker, S., Greaves, M. & Elderfield, H. A study of cleaning procedures used for foraminiferal Mg/Ca paleothermometry. Geochem. Geophys. Geosyst. 4 8407 10.10292003GC000559 (2003)

    Article  ADS  Google Scholar 

  32. Anand, P., Elderfield, H. & Conte, M. H. Calibration of Mg/Ca thermometry in planktonic foraminifera from a sediment trap time series. Paleoceanography 18 1050 10.1029/2002PA000846 (2003)

    Article  ADS  Google Scholar 

  33. Wilkinson, B. H. & Algeo, T. J. Sedimentary carbonate record of calcium-magnesium cycling at the Earth’s surface. Am. J. Sci. 289, 1158–1194 (1989)

    Article  ADS  CAS  Google Scholar 

  34. Klochko, K., Kaufman, A. J., Yao, W., Berne, R. H. & Tossell, J. A. Experimental measurement of boron isotope fractionation in seawater. Earth Planet. Sci. Lett. 248, 276–285 (2006)

    Article  ADS  CAS  Google Scholar 

  35. Dickson, A. G. Thermodynamics of the dissociation of boric acid in synthetic seawater from 273.15 to 318.15 K. Deep-Sea Res. 37, 755–766 (1990)

    Article  ADS  CAS  Google Scholar 

  36. Pearson, P. N. & Palmer, M. R. Atmospheric carbon dioxide concentrations over the past 60 million years. Nature 406, 695–699 (2000)

    Article  ADS  CAS  Google Scholar 

  37. Horita, J., Zimmermann, H. & Holland, H. D. Chemical evolution of seawater during the Phanerozoic: implications from the record of marine evaporates. Geochim. Cosmochim. Acta 66, 3733–3756 (2002)

    Article  ADS  CAS  Google Scholar 

  38. Tyrrell, T. & Zeebe, R. E. History of carbonate ion concentration over the last 100 million years. Geochim. Cosmochim. Acta 68, 3521–3534 (2004)

    Article  ADS  CAS  Google Scholar 

Download references

Acknowledgements

This work was supported by NERC grants to P.N.P., B.S.W. and G.L.F. We thank the Tanzania Petroleum Development Corporation, the Tanzania Commission for Science and Technology and the Tanzania Drilling Project field team for support. We are grateful to T. Elliott for discussions.

Author Contributions P.N.P. led the study and fieldwork, prepared foraminifer samples for isotope analysis and wrote the initial draft. G.L.F. conducted all isotope and trace element analyses and calculations and drafted the figures. B.S.W. contributed to fieldwork and prepared foraminifer samples for trace element analyses. All authors contributed to the final text.

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Paul N. Pearson.

Supplementary information

Supplementary Data

This file consists of Supplementary Table 1 which contains Boron Isotopic Data T. ampliapertura (212-250 mm) from TDP12 and TDP17 across the Eocene-Oligocene Transition and Supplementary Table 2 which contains Mg/Ca Data for samples from TDP12 and TDP17. (XLS 35 kb)

PowerPoint slides

Rights and permissions

Reprints and permissions

About this article

Cite this article

Pearson, P., Foster, G. & Wade, B. Atmospheric carbon dioxide through the Eocene–Oligocene climate transition. Nature 461, 1110–1113 (2009). https://doi.org/10.1038/nature08447

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/nature08447

This article is cited by

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.

Search

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