I am interested in the insights that chemicals measured in polar ice cores can offer into past changes in the earth system, particularly interactions between atmospheric chemistry, composition and climate.

To date, much of my work at BAS has focussed on the causes of changes in the concentration of methane in the atmosphere accompanying past changes in climate, for example the near-doubling in concentration between the Last Glacial Maximum (21,000 years ago) and the relatively warm pre-industrial era (200 years ago).  A full understanding of the causes is a prerequisite to meaningful future predictions of methane concentration, with implications for both our climate and air quality.

The study of methane sources and sinks, and how they respond to changes in climate, also yields insights into important feedbacks between the atmosphere and biosphere - two key components of the earth system - of which ice cores provide an 800,000 year record.