For hundreds of millions of years, Earth’s climate has warmed and cooled with natural fluctuations in the level of carbon dioxide (CO₂) in the atmosphere.
I am a sedimentologist and have worked extensively on a variety of sedimentary rocks and sediments ranging in age from the Archaean to the Quaternary. My current research is focused on the long-term geological carbon cycle that drives the Earth’s climate between icehouse and hothouse extremes. I am especially interested in one of the least known components of this cycle — sedimentary carbon that has been sequestered in deep-sea sediments since about 120 million years ago. Quantifying this on a global scale involves working with vast amounts of existing ocean-drilling data, collected over many decades, and analysing these data in a framework of changing tectonic plates. I have also worked on creating the first digital map of seafloor sediments, polymetallic nodules, deep-sea drift deposits, deep-sea hiatuses, deep-sea carbonate fluxes through time, Quaternary salt lakes and their paleoclimate records, Australian opal deposits, and early life on Earth.