Past environments, past climates and impacts of major environmental change.
It has long been recognised by geologists that Earth's climate has changed over timescales of thousands to millions of years. Understanding the record and drivers of these past changes informs our knowledge of the environmental history and biotic evolution of our planet but also provides insights into ongoing, and future, anthropogenically-forced, climate change. Critically, the range of past climate states represented in the geological record allow us to probe the major controls and mechanisms that affect climate over a range of atmospheric CO2 levels. This allows us to offer perspectives on Earth system variables that are critical to predicting future climate change, such as climate sensitivity to CO2 (the amount of global warming that will occur in response to a doubling of atmospheric CO2). This talk will explore some of the ways that geologists reconstruct past climates and discuss examples of how the geological past can contribute to predictions of, and solutions for, the future.



Research profile
My research focuses on the study of past environments, past climates and the impacts of major environmental change. In particular, I focus on how 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 Era (250 to 65 million years ago) and early Cenozoic (65 to 35 Ma). Warm intervals in Earth history, characterised by an absence of large 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 help inform our understanding of how our planet may evolve in the future in response to anthropogenic CO2 release.
I use a multidisciplinary approach drawing on geology, palaeontology and geochemistry to reconstruct Earth history and work closely with climate modellers. The comparison of model simulations of Earth’s past climates compared with proxy records of climate allows us to gain mechanistic insights into the workings of the Earth system. I have conducted fieldwork in many parts of the world and participated in two scientific ocean drilling expeditions.

Image: Stuart Robinson