Research Fellows Directory
Dr Stuart Robinson
University College London
My research focuses on the Cretaceous period in Earth history (145 to 65-million years ago), when the climate was much warmer then than it is today. At times during the Cretaceous the remains of dead microscopic organisms, algae and bacteria sunk to the ocean floor and accumulated as ‘organic matter’. In the modern ocean, most of the dead organisms decay before reaching the sea floor due to the abundance of oxygen dissolved in seawater. During the Cretaceous the oxygen content of seawater was low, allowing the organic matter to settle on the sea floor, which may have led to changes in the amount of carbon dioxide (CO2) in the atmosphere and global climate change.
I aim to understand how ocean circulation, climate and atmospheric CO2 caused and responded to times of organic matter accumulation during the Cretaceous. This is achieved by applying different techniques to the geological record. By analyzing the chemistry of different geological materials, such as fossil-fish teeth, or sediments, I can reconstruct features of past environments, such as how the oceans mixed and what water temperatures were. The abundance of pores on fossil plant leaves collected through a sequence of rocks allows me to reconstruct Cretaceous atmospheric CO2 levels through time.
Reconstructing the climates of Earth’s past is an exciting area to work in because many unknowns need to be quantified and this requires broad, creative scientific. The geological record allows us to see how the Earth, and life on it, has responded to natural changes in CO2 during the past. Predictions for future climate rely on accurate global climate models, which can also be used to simulate periods in the past. By comparing models of past climate with climate reconstructions based on the geological record, it is possible to assess how good the climate models are at predicting climatic conditions that are very different from those today, including those we may experience in the future.
Interests and expertise (Subject groups)