Research Interests

My research focuses on critical moments in Earth's history, as defined by abrupt climatic changes, mass extinctions or innovative evolutionary events. For over a decade, the overarching theme of my research group has been to establish a secure mechanistic basis for interpreting palaeoclimatic clues from the plant fossil record, and for investigating the fundamental nature of ancient biosphere-atmosphere-climate feedbacks.

Developing an integrative interdisciplinary approach requires me to work at the boundaries between three traditional academic disciplines: palaeobotany, palaeoclimatology and plant physiology and utilize a variety of investigative techniques. These, broadly, fall into three categories: (i) morphological and geochemical analyses of fossil plant materials, (ii) laboratory-based experimental programmes, designed to reveal how modern genotypes operate in simulated ancient atmospheres and climates, and (iii) theoretical modelling.

Combining the first two lines of investigative enquiry provides a powerful and flexible means for extracting quantitative atmospheric and climatic information from the rock record. Information extracted from the fossils secures some key boundary conditions required for ensuing global simulations of the biogeochemical interactions between different components of the earth system, especially the terrestrial biosphere, the atmosphere and the geochemical carbon cycle. Documentation of temporal trends in atmospheric CO₂, as a greenhouse gas, using fossil leaves as palaeo-CO₂ barometers, plays an important role in this field of research.