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Eocene to Oligocene terrestrial Southern Hemisphere cooling caused by declining pCO2

Abstract

The greenhouse-to-icehouse climate transition from the Eocene into the Oligocene is well documented by sea surface temperature records from the southwest Pacific and Antarctic margin, which show evidence of pronounced long-term cooling. However, identification of a driving mechanism depends on a better understanding of whether this cooling was also present in terrestrial settings. Here, we present a semi-continuous terrestrial temperature record spanning from the middle Eocene to the early Oligocene (~41–33 million years ago), using bacterial molecular fossils (biomarkers) preserved in a sequence of southeast Australian lignites. Our results show that mean annual temperatures in southeast Australia gradually declined from ~27 °C (±4.7 °C) during the middle Eocene to ~22–24 °C (±4.7 °C) during the late Eocene, followed by a ~2.4 °C-step cooling across the Eocene/Oligocene boundary. This trend is comparable to other temperature records in the Southern Hemisphere, suggesting a common driving mechanism, likely \(p{{\rm{CO}}_{2}}\). We corroborate these results with a suite of climate model simulations demonstrating that only simulations including a decline in \(p{{\rm{CO}}_{2}}\) lead to a cooling in southeast Australia consistent with our proxy record. Our data form an important benchmark for testing climate model performance, sea–land interaction and climatic forcings at the onset of a major Antarctic glaciation.

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Fig. 1: Middle Eocene to early Oligocene temperatures.
Fig. 2: Terrestrial temperatures versus SSTs.
Fig. 3: Comparison with climate model simulations.

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Data availability

All of the lignite data supporting the findings of this study and the compilation of previously published SST records used in Fig. 2 and Extended Data Fig. 3 are available in Supplementary Data 1. All data are available via PANGAEA at https://doi.org/10.1594/PANGAEA.933176 and the model simulation data are available via the freely accessible Bristol Research Initiative for the Dynamic Global Environment server at https://www.paleo.bristol.ac.uk/ummodel/scripts/papers/, as is the standard protocol at the University of Bristol.

References

  1. Westerhold, T. et al. An astronomically dated record of Earth’s climate and its predictability over the last 66 million years. Science 369, 1383–1387 (2020).

    Article  Google Scholar 

  2. Coxall, H. K. et al. Rapid stepwise onset of Antarctic glaciation and deeper calcite compensation in the Pacific Ocean. Nature 433, 53–57 (2005).

    Article  Google Scholar 

  3. Scher, H., Bohaty, S. M., Zachos, J. C. J. C. & Delaney, M. L. Two-stepping into the icehouse: East Antarctic weathering during progressive ice-sheet expansion at the Eocene–Oligocene transition. Geology 39, 383–386 (2011).

    Article  Google Scholar 

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

    Article  Google Scholar 

  5. Coxall, H. K. et al. Export of nutrient rich Northern Component Water preceded early Oligocene Antarctic glaciation. Nat. Geosci. 11, 190–196 (2018).

    Article  Google Scholar 

  6. Houben, A. J. P. et al. Reorganization of Southern Ocean plankton ecosystem at the onset of Antarctic glaciation. Science 340, 341–344 (2013).

    Article  Google Scholar 

  7. Bijl, P. K. et al. Eocene cooling linked to early flow across the Tasmanian Gateway. Proc. Natl Acad. Sci. USA 110, 9645–9650 (2013).

    Article  Google Scholar 

  8. Kennett, J. P. Cenozoic evolution of Antarctic glaciation, the circum-Antarctic Ocean, and their impact on global paleoceanography. J. Geophys. Res. 82, 3843–3860 (1977).

    Article  Google Scholar 

  9. Anagnostou, E. et al. Changing atmospheric CO2 concentration was the primary driver of early Cenozoic climate. Nature 533, 380–384 (2016).

    Article  Google Scholar 

  10. Cramwinckel, M. J. et al. Synchronous tropical and polar temperature evolution in the Eocene. Nature 559, 382–386 (2018).

    Article  Google Scholar 

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

    Article  Google Scholar 

  12. Mckay, D. I. A., Tyrrell, T. & Wilson, P. A. Global carbon cycle perturbation across the Eocene–Oligocene climate transition. Paleoclimatology 31, 311–329 (2016).

    Google Scholar 

  13. Houben, A. J. P., van Mourik, C. A., Montanari, A., Coccioni, R. & Brinkhuis, H. The Eocene–Oligocene transition: changes in sea level, temperature or both? Palaeogeogr. Palaeoclimatol. Palaeoecol. 335–336, 75–83 (2012).

    Article  Google Scholar 

  14. Pälike, H. et al. A Cenozoic record of the equatorial Pacific carbonate compensation depth. Nature 488, 609–614 (2012).

    Article  Google Scholar 

  15. Elsworth, G., Galbraith, E., Halverson, G. & Yang, S. Enhanced weathering and CO2 drawdown caused by latest Eocene strengthening of the Atlantic meridional overturning circulation. Nat. Geosci. 10, 213–216 (2017).

    Article  Google Scholar 

  16. Stickley, C. E. et al. Timing and nature of the deepening of the Tasmanian Gateway. Paleoceanogr. Paleoclimatol. 19, PA4027 (2004).

    Google Scholar 

  17. Goldner, A., Herold, N. & Huber, M. Antarctic glaciation caused ocean circulation changes at the Eocene–Oligocene transition. Nature 511, 574–577 (2014).

    Article  Google Scholar 

  18. Hutchinson, D. K. et al. The Eocene–Oligocene transition: a review of marine and terrestrial proxy data, models and model-data comparisons. Clim. Past 17, 269–315 (2021).

    Article  Google Scholar 

  19. Bijl, P. K. et al. Early Palaeogene temperature evolution of the southwest Pacific Ocean. Nature 461, 776–779 (2009).

    Article  Google Scholar 

  20. Śliwińska, K. K., Thomsen, E., Schouten, S., Schoon, P. L. & Heilmann-Clausen, C. Climate- and gateway-driven cooling of Late Eocene to earliest Oligocene sea surface temperatures in the North Sea Basin. Sci. Rep. 9, 4458 (2019).

    Article  Google Scholar 

  21. Liu, Z. et al. Transient temperature asymmetry between hemispheres in the Palaeogene Atlantic Ocean. Nat. Geosci. 11, 656–660 (2018).

    Article  Google Scholar 

  22. 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, 969–973 (2009).

    Article  Google Scholar 

  23. Hren, M. T. et al. Terrestrial cooling in Northern Europe during the Eocene–Oligocene transition. Proc. Natl Acad. Sci. USA 110, 7562–7567 (2013).

    Article  Google Scholar 

  24. Schouten, S. et al. Onset of long-term cooling of Greenland near the Eocene–Oligocene boundary as revealed by branched tetraether lipids. Geology 36, 147–150 (2008).

    Article  Google Scholar 

  25. Zanazzi, A., Kohn, M. J., Macfadden, B. J. & Terry, D. O. Large temperature drop across the Eocene–Oligocene transition in central North America. Nature 445, 639–642 (2007).

    Article  Google Scholar 

  26. Seton, M. et al. Global continental and ocean basin reconstructions since 200 Ma. Earth Sci. Rev. 113, 212–270 (2012).

    Article  Google Scholar 

  27. Korasidis, V. A., Wallace, M. W., Dickinson, J. A. & Hoffman, N. Depositional setting for Eocene seat earths and related facies of the Gippsland Basin, Australia. Sediment. Geol. 390, 100–113 (2019).

    Article  Google Scholar 

  28. Holdgate, G. R., Sluiter, I. R. K. & Taglieri, J. Eocene–Oligocene coals of the Gippsland and Australo-Antarctic basins—paleoclimatic and paleogeographic context and implications for the earliest Cenozoic glaciations. Palaeogeogr. Palaeoclimatol. Palaeoecol. 472, 236–255 (2017).

    Article  Google Scholar 

  29. Korasidis, V. A., Wallace, M. W., Wagstaff, B. E. & Hill, R. S. Terrestrial cooling record through the Eocene–Oligocene transition of Australia. Glob. Planet. Change 173, 61–72 (2019).

    Article  Google Scholar 

  30. Inglis, G. N. et al. Distributions of geohopanoids in peat: implications for the use of hopanoid-based proxies in natural archives. Geochim. Cosmochim. Acta 224, 249–261 (2018).

    Article  Google Scholar 

  31. Hopmans, E. C. et al. A novel proxy for terrestrial organic matter in sediments based on branched and isoprenoid tetraether lipids. Earth Planet. Sci. Lett. 224, 107–116 (2004).

    Article  Google Scholar 

  32. Weijers, J. W. H. H., Schouten, S., van den Donker, J. C., Hopmans, E. C. & Sinninghe Damsté, J. S. Environmental controls on bacterial tetraether membrane lipid distribution in soils. Geochim. Cosmochim. Acta 71, 703–713 (2007).

    Article  Google Scholar 

  33. Naafs, B. D. A. et al. Introducing global peat-specific temperature and pH calibrations based on brGDGT bacterial lipids. Geochim. Cosmochim. Acta 208, 285–301 (2017).

    Article  Google Scholar 

  34. Weijers, J. W. H. H., Steinmann, P., Hopmans, E. C., Schouten, S. & Sinninghe Damsté, J. S. Bacterial tetraether membrane lipids in peat and coal: testing the MBT–CBT temperature proxy for climate reconstruction. Org. Geochem. 42, 477–486 (2011).

    Article  Google Scholar 

  35. Zheng, Y. et al. Atmospheric connections with the North Atlantic enhanced the deglacial warming in northeast China. Geology 45, 1031–1034 (2017).

    Article  Google Scholar 

  36. Naafs, B. D. A. et al. High temperatures in the terrestrial mid-latitudes during the early Palaeogene. Nat. Geosci. 11, 766–771 (2018).

    Article  Google Scholar 

  37. Korasidis, V. A. et al. Cyclic floral succession and fire in a Cenozoic wetland/peatland system. Palaeogeogr. Palaeoclimatol. Palaeoecol. 461, 237–252 (2016).

    Article  Google Scholar 

  38. Tierney, J. E. & Tingley, M. P. A Bayesian, spatially-varying calibration model for the TEX86 proxy. Geochim. Cosmochim. Acta 127, 83–106 (2014).

    Article  Google Scholar 

  39. Houben, A. J. P., Bijl, P. K., Sluijs, A., Schouten, S. & Brinkhuis, H. Late Eocene Southern Ocean cooling and invigoration of circulation preconditioned Antarctica for full‐scale glaciation. Geochem. Geophys. Geosyst. 20, 2214–2234 (2019).

    Google Scholar 

  40. Pagani, M. et al. The role of carbon dioxide during the onset of antarctic glaciation. Science 334, 1261–1264 (2011).

    Article  Google Scholar 

  41. Hartman, J. D. et al. Paleoceanography and ice sheet variability offshore Wilkes Land, Antarctica—part 3: insights from Oligocene–Miocene TEX86-based sea surface temperature reconstructions. Clim. Past 14, 1275–1297 (2018).

    Article  Google Scholar 

  42. Retallack, G. J. Cenozoic paleoclimate on land in North America. J. Geol. 115, 271–294 (2007).

    Article  Google Scholar 

  43. Sheldon, N. D., Costa, E., Cabrera, L. & Garcés, M. Continental climatic and weathering response to the Eocene–Oligocene transition. J. Geol. 120, 227–236 (2012).

    Article  Google Scholar 

  44. Kohn, M. J. et al. Quasi-static Eocene–Oligocene climate in Patagonia promotes slow faunal evolution and mid-Cenozoic global cooling. Palaeogeogr. Palaeoclimatol. Palaeoecol. 435, 24–37 (2015).

    Article  Google Scholar 

  45. Colwyn, D. A. & Hren, M. T. An abrupt decrease in Southern Hemisphere terrestrial temperature during the Eocene–Oligocene transition. Earth Planet. Sci. Lett. 512, 227–235 (2019).

    Article  Google Scholar 

  46. Pound, M. J. & Salzmann, U. Heterogeneity in global vegetation and terrestrial climate change during the late Eocene to early Oligocene transition. Sci. Rep. 7, 43386 (2017).

    Article  Google Scholar 

  47. Valdes, P. J. et al. The BRIDGE HadCM3 family of climate models: HadCM3@Bristol v1.0. Geosci. Model Dev. 10, 3715–3743 (2017).

    Article  Google Scholar 

  48. Kennedy-Asser, A. T., Lunt, D. J., Farnsworth, A. & Valdes, P. J. Assessing mechanisms and uncertainty in modeled climatic change at the Eocene–Oligocene transition. Paleoceanogr. Paleoclimatol. 34, 16–34 (2019).

    Article  Google Scholar 

  49. Lunt, D. J. et al. A model–data comparison for a multi-model ensemble of early Eocene atmosphere–ocean simulations: EoMIP. Clim. Past 8, 1717–1736 (2012).

    Article  Google Scholar 

  50. Kennedy-Asser, A. T. et al. Changes in the high-latitude Southern Hemisphere through the Eocene–Oligocene transition: a model-data comparison. Clim. Past 16, 555–573 (2020).

    Article  Google Scholar 

  51. Baatsen, M. et al. The middle to late Eocene greenhouse climate modelled using the CESM 1.0.5. Clim. Past 16, 2573–2597 (2020).

    Article  Google Scholar 

  52. Hopmans, E. C., Schouten, S. & Sinninghe Damsté, J. S. The effect of improved chromatography on GDGT-based palaeoproxies. Org. Geochem. 93, 1–6 (2016).

    Article  Google Scholar 

  53. De Jonge, C. et al. Occurrence and abundance of 6-methyl branched glycerol dialkyl glycerol tetraethers in soils: implications for palaeoclimate reconstruction. Geochim. Cosmochim. Acta 141, 97–112 (2014).

    Article  Google Scholar 

  54. Yamamuro, M. & Kayanne, H. Rapid direct determination of organic carbon and nitrogen in carbonate-bearing sediments with a Yanaco MT-5 CHN analyzer. Limnol. Oceanogr. 40, 1001–1005 (1995).

    Article  Google Scholar 

  55. Lunt, D. J. et al. Palaeogeographic controls on climate and proxy interpretation. Clim. Past 12, 1181–1198 (2016).

    Article  Google Scholar 

  56. Passchier, S. et al. Early Eocene to middle Miocene cooling and aridification of East Antarctica. Geochem. Geophys. Geosyst. 14, 1399–1410 (2013).

    Article  Google Scholar 

  57. Passchier, S., Ciarletta, D. J., Miriagos, T. E., Bijl, P. K. & Bohaty, S. M. An Antarctic stratigraphic record of stepwise ice growth through the Eocene–Oligocene transition. Geol. Soc. Am. Bull. 129, 318–330 (2017).

    Article  Google Scholar 

  58. Sheldon, N. D., Retallack, G. J. & Tanaka, S. Geochemical climofunctions from North American soils and application to paleosols across the Eocene–Oligocene boundary in Oregon. J. Geol. 110, 687–696 (2002).

    Article  Google Scholar 

  59. Sheldon, N. D. & Retallack, G. J. Regional paleoprecipitation records from the Late Eocene and Oligocene of North America. J. Geol. 112, 487–494 (2004).

    Article  Google Scholar 

  60. Fan, M., Ayyash, S. A., Tripati, A., Passey, B. H. & Griffith, E. M. Terrestrial cooling and changes in hydroclimate in the continental interior of the United States across the Eocene–Oligocene boundary. Bull. Geol. Soc. Am. 130, 1073–1084 (2018).

    Article  Google Scholar 

  61. Page, M. et al. Synchronous cooling and decline in monsoonal rainfall in northeastern Tibet during the fall into the Oligocene icehouse. Geology 47, 203–206 (2019).

    Article  Google Scholar 

  62. Kohn, M. J. et al. Climate stability across the Eocene–Oligocene transition, southern Argentina. Geology 32, 621–624 (2004).

    Article  Google Scholar 

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Acknowledgements

We thank NERC (reference: CC010) and NEIF (www.isotopesuk.org) for funding and maintenance of the instrumentation used for this work. We thank S. Blackbird at the University of Liverpool for technical assistance with the TOC analyses. This research was carried out with funding from the European Research Council under the European Union’s Seventh Framework Programme (FP/2007-2013) and European Research Council Grant Agreement number 340923 “The greenhouse earth system” T-GRES (awarded to R.D.P.). Further funding was provided by the Royal Society as part of a Tata University Research Fellowship to B.D.A.N. and the associated enhancement award that funded V.L. Climate model simulations were carried out using the computational facilities of the Advanced Computing Research Centre, University of Bristol, and were supported by NERC (grant number NE/L002434/1).

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Authors and Affiliations

Authors

Contributions

B.D.A.N. and V.L. designed the project. V.L. performed all of the biomarker analyses. A.T.K.-A. and D.J.L. performed the HadCM3BL model simulations. P.J.V. performed the supplementary simulations (Extended Data Fig. 6). V.A.K. and M.W.W. provided the samples, as well as palynological and stratigraphic information. V.L. wrote the manuscript with contributions from all authors.

Corresponding authors

Correspondence to Vittoria Lauretano or B. David A. Naafs.

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The authors declare no competing interests.

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Peer review information Nature Geoscience thanks Michael Hren and the other, anonymous, reviewer(s) for their contribution to the peer review of this work. Primary Handling Editor: James Super.

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Extended data

Extended Data Fig. 1 TOC% content.

Total Organic Carbon (TOC) wt.% content vs MAATpeat. Only samples with >30 wt.% were interpreted for MAATpeat analyses.

Extended Data Fig. 2 Nonmetric multidimensional scaling (NMDS).

Nonmetric multidimensional scaling (NMDS) by species relative abundance matrix29. Samples are coded by coal seam and age as indicated in the key.

Extended Data Fig. 3 Comparison with available terrestrial EOT geochemical proxy records.

Compilation of terrestrial temperature quantitative proxy records across the Eocene/Oligocene23,24,25,43,45,56,57,58,59,60,61,62 depicting the degree of cooling for each proxy record and time span at each location. Full circles represent land-based records, while empty circles indicate records of terrestrial temperature change derived from marine sediment cores. (Map from Ocean Data View, https://odv.awi.de/).

Extended Data Fig. 4 Modelled Mean annual air temperature (MAAT).

a, Modelled mean annual air temperature (MAAT) for each of the 8 simulations used in this analysis (black dots and error bars) compared to the South Australia lignite record (coloured dots and error bars). Model error is taken as the maximum and minimum values from the 3 × 3 grid cell box surrounding the proxy location. Annual mean temperatures display a cold bias both before and after the EOT (see text). b, Maps showing the MAAT for each simulation over the South Australia region.

Extended Data Fig. 5 Model spin-up.

Spin-up trends showing the mean annual air temperature for the South Australia region with a 50-year running climatology. Gaps in time series show where simulations were continued or extended.

Extended Data Fig. 6 Tasman Seaway.

Modelled mean annual temperature change in response to a deepening Tasman Seaway (from 100 to 1,500 m depth). Note: these simulations used an alternate model configuration and spin-up procedure and are therefore for illustrative purposes only.

Extended Data Table 1 Climate model simulations.

Model simulation details.

Extended Data Table 2 Climate model boundary conditions.

Boundary conditions of pairs of model simulations used to recreate changes across the EOT. Boundary conditions that remain the same before and after the EOT are shaded in grey.

Supplementary information

Supplementary Information

Supplementary discussion and references.

Supplementary Data 1

Supplementary Tables 1–3.

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Lauretano, V., Kennedy-Asser, A.T., Korasidis, V.A. et al. Eocene to Oligocene terrestrial Southern Hemisphere cooling caused by declining pCO2. Nat. Geosci. 14, 659–664 (2021). https://doi.org/10.1038/s41561-021-00788-z

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