Since the industrial revolution the concentration of atmospheric CO2 has increased. This potent greenhouse gas is already causing demonstrable climate change. Important insights into exactly how the climate will change in the future in response to increased greenhouse emissions can be gained from looking into the past to those time periods that were warmer than today.
Key Questions
1. What is the sensitivity of the climate system to CO2 forcing? – how hot will it get in the future?
2. What is the relationship between CO2, ice-volume and sea level? – how high will sea level rise as the major ice sheets melt in the future?
How do we do it?
We use cutting edge analytical techniques to measure the chemical and boron isotopic composition of the calcium carbonate shells of single celled organisms called foraminifera.
These animals lived in the ancient ocean and their shells now make up deep ocean sediments. Such sediments represent a continuous archive of ancient climate that stretches back continuously for up to 65 million years.
From the chemical and isotopic signals locked up in the shells of these animals we can reconstruct ocean pH (and hence atmospheric CO2 ), ice volume (and hence sea-level) and water temperature (and hence climate).
Recent Publications
Brown, R.M., Chalk, T.B., Crocker, A.J., Wilson, P.A., Foster, G.L., (2022) Late Miocene cooling coupled to carbon dioxide with Pleistocene-like climate sensitivity, Nature Geoscience, https://doi.org/10.1038/s41561-022-00982-7. Data here
Babila, T.L., Penman, D.E., Standish, C.D., Doubrawa, M., Bralower, T.J., Robinson, M.M., Self-Trail, J.M., Speijer, R.P., Stassen, P., Foster, G.L., Zachos, J.C. (2022) Surface ocean warming and acidification driven by rapid carbon release precedes Paleocene-Eocene Thermal Maximum, Science Advances, 8, 11, eabg1025, doi: 10.1126/sciadv.abg1025.
Lunt, D.J., Bragg, F., Chan, W.-L. et al. including Foster, G.L. (2021) DeepMIP: Model intercomparison of early Eocene climatic optimum (EECO) large-scale climate features and comparison with proxy data, Climate of the Past, 17, 203-227, https://doi.org/10.5194/cp-17-203-2021
Rohling, E.J., Yu, J., Heslop, D., Foster, G.L., Opdyke, B., Roberts, A.P. (2021) Sea level and deep-sea temperature reconstructions suggest quasi-stable states and critical transitions over the past 40 million years, Science Advances, 7, 26, eabf5326, https://advances.sciencemag.org/content/7/26/eabf5326.abstract
Rae, J.W.B, Zhang, Y-G., Liu, Z., Foster, G.L. Stoll, H.M., (2021) Atmospheric CO2 over the last 66 million years from marine archives, Annual Reviews of Earth and Planetary Sciences, Vol. 49:609-641, https://doi.org/10.1146/annurev-earth-082420-063026
Lear, C.H., Anand, P., Blenkinsop, T., Foster, G.L., Gagen, M., Hoogakker, B., Larter, R.D., Lunt, D.J., McCave, I.N., McClymont, E., Pancost, R.D., Rickaby, R.E.M., Schultz, D.M., Summerhayes, C., Williams, C.J.R., Zalasiewicz, J. (2021) Geological Society of London Scientific Statement: what the geological record tells us about our present and future climate, Journal of the Geological Society, 178, jgs2020-239, https://doi.org/10.1144/jgs2020-239
Tierney, J. E., Poulsen, C. J., Montanez, I., Bhattacharya, T., Feng, R., Ford, H., Hönisch, B., Inglis, G., Petersen, S., Sagoo, N., Tabor, C., Thirumalai, K., Zhu, J., Burls, N., Godderis, Y., Foster, G., Huber, B. T., Ivany, L., Kirtland Turner, S., ... Ge Zhang, Y. (2020). Past climates inform our future. Science, 370(6517), [eaay3701]. https://doi.org/10.1126/science.aay3701
Inglis, G. N., Bragg, F., Burls, N. J., Cramwinckel, M. J., Evans, D., Foster, G. L., Huber, M., Lunt, D. J., Siler, N., Steinig, S., Tierney, J. E., Wilkinson, R., Anagnostou, E., De Boer, A. M., Dunkley Jones, T., Edgar, K. M., Hollis, C. J., Hutchinson, D. K., & Pancost, R. D. (2020). Global mean surface temperature and climate sensitivity of the early Eocene Climatic Optimum (EECO), Paleocene–Eocene Thermal Maximum (PETM), and latest Paleocene. Climate of the Past, 16(5), 1953-1968. [1953]. https://doi.org/10.5194/cp-16-1953-2020
Anagnostou, E., John, E.H., Babila, T.L., Sexton, P.F., Ridgwell, A., Lunt, D.J., Pearson, P.N., Chalk, T.B., Pancost, R.D., Foster, G.L. (2020) The State-dependency of climate sensitivity in the Eocene greenhouse, Nature Communications, 11:4436, https://doi.org/10.1038/s41467-020-17887-x, data tables here, here and here
Sherwood, S., Webb, M. J., Annan, J. D., Armour, K. C., Forster, P. M., Hargreaves, J. C., Hegerl, G., Klein, S. A., Marvel, K. D., Rohling, E. J., Watanabe, M., Andrews, T., Braconnot, P., Bretherton, C. S., Foster, G. L., Hausfather, Z., Heydt, A. S. V. D., Knutti, R., Mauritsen, T., ... Zelinka, M. D. (2020). An assessment of Earth's climate sensitivity using multiple lines of evidence. Reviews of Geophysics, [e2019RG000678]. https://doi.org/10.1029/2019RG000678
de la Vega, Chalk, T.B., Wilson, P.A., Priya Bysani, R., Foster, G.L. (2020) Atmospheric CO2 during the Mid-Piacenzian Warm Period and the M2 glaciation, Nature Scientific Reports, 10(1), 1-8, https://doi.org/10.1038/s41598-020-67154-8. click here for data