The overarching question driving my research is “how does the Earth system work when atmospheric CO2 levels are very high?”. To address this question, I focus on how different components of the Earth system (e.g. climate, carbon cycling, oceanography) have operated in the geological past, with a particular interest in periods of extreme greenhouse warmth, such as the Mesozoic and early Cenozoic (250 to 35 million years ago). Warm intervals in Earth history, characterised by an absence of polar ice sheets, high sea levels, and major perturbations to ocean chemistry, provide examples of how the Earth system works under very different boundary conditions to the present day. Understanding the processes operating in the geological past can then help inform our understanding of how our planet may evolve in the future in response to anthropogenic CO2 release. My work draws on a multidisciplinary approach utilising evidence from geology, palaeontology and geochemistry (of all types including stable and radiogenic isotopes, noble gases and organic geochemistry) to reconstruct Earth history. Fieldwork and working with sedimentary cores from the deep-sea and land are vital components to my approach.
Recent and current research includes constraining variations in Cretaceous sea surface temperatures, climate sensitivity through time, palaeohydrology of warm climates, rates of change during major carbon cycle perturbations, the long-term evolution of ocean circulation, and the causes and consequences of marine anoxia (oceanic anoxic events).
I am keen to supervise students who are interested in reconstructing and understanding Earth’s climatic and environmental history through any combination of sedimentology, stratigraphy, geochemistry and palaeontology.
Current areas of interest include (more details at: https://www.earth.ox.ac.uk/teaching/graduates/dphil-projects/):
Atmospheric pCO2 change, carbon cycling and climate during Mesozoic Oceanic Anoxic Events
Constraining the tempo of Mesozoic Oceanic Anoxic Events using extra-terrestrial He-isotopes
Tracking upper ocean circulation in the Cretaceous ocean