About the project
The magnitude of future warming will depend upon the strength of carbon cycle feedback mechanisms. However, there are carbon cycle feedbacks that we still know little about. This PhD project will test whether CO2 release from sedimentary rocks is a missing carbon cycle feedback in past and future warm climates.
Over the last 150 years, anthropogenic activities have released vast quantities of carbon dioxide (CO2) into the atmosphere, resulting in higher global temperatures. The precise magnitude of future warming is dependent upon carbon cycle feedbacks, which can either amplify or mitigate warming.
The latest generation of future climate models include several key carbon cycle feedback mechanisms. However, there are carbon cycle feedbacks that we know very little about and have the potential to take future climate in unimagined directions.
The geological record captures the response of the Earth system to all the feedbacks in operation, including those that we are unaware of. Recent work suggests that exposure of rock organic carbon to oxidative weathering at the Earth’s surface may have been an important carbon cycle feedback that plays a key role in controlling atmospheric CO2 over geological timescales. However, our knowledge of rock organic carbon oxidation in past warm climates is unknown.
This PhD project will use a novel data-modelling approach (ref. 2-3) to test whether rock organic carbon oxidation was responsible for modulating atmospheric CO2 change during major climate transitions during the Cenozoic and Mesozoic, including the Paleocene Eocene thermal maximum (56 million years ago) and the mid-Miocene Climatic Optimum (~15 million years ago). The results will help evaluate whether state-of-the-art Earth system models currently underestimate the climate response to CO2-driven warming in past warm climates.
References
[1] Hilton, R.G. and West, A.J., 2020. Mountains, erosion and the carbon cycle. Nature Reviews Earth & Environment, 1(6), pp.284-299.
[2] Hollingsworth, E.H., Elling, F.J., Badger, M.P.S., Pancost, R.D., Dickson, A.J., Rees‐Owen, R.L., Papadomanolaki, N.M., Pearson, A., Sluijs, A., Freeman, K.H. and Baczynski, A.A., 2024. Spatial and Temporal Patterns in Petrogenic Organic Carbon Mobilization During the Paleocene‐Eocene Thermal Maximum. Paleoceanography and Paleoclimatology, 39(2), p.e2023PA004773.
[3] Mills, B.J., Donnadieu, Y. and Goddéris, Y., 2021. Spatial continuous integration of Phanerozoic global biogeochemistry and climate. Gondwana Research, 100, pp.73-86.
Supervisors
As well as Dr Gordon Inglis, Dr Richard Stockey and Professor Tom Gernon, you will be supervised by Professor Ben Mills from the University of Leeds.
