My main area of research is concerned with the global growth of Montreal Protocol gases or gases that are involved in stratospheric ozone depletion (CFCs, HCFCs, halons) and the Kyoto gases or gases that are involved in global warming (CO₂, CH₄, N₂O, SF₆, NF₃, HFCs and PFCs). Measurement of these key compounds is vital in obtaining a greater understanding of the processes involved in Climate Change and Ozone Depletion. This internationally recognised work is funded by Department for Energy Security and Net Zero (DESNZ), the Irish Environmental Protection Agency (EPA), Met Eireaan, the National Aeronautics and Space Administration (NASA) and the National Oceanic and Atmospheric Administration (NOAA).

As a member of the Advanced Global Gases Experiment (AGAGE) team, I am a principal scientist involved with three AGAGE research stations (Mace Head, Ireland; Tacolneston, UK; and Ragged Point Barbados). AGAGE is one of only two groups in the world making in situ ground based global measurements of these compounds. This area of research has expanded in recent years with national and EU funded projects such as ICOS, PARIS, InHALE, GEMMA.

I founded the UK DECC Network. This network incorporates a range of novel measurement approaches, and is a collaboration between the University of Bristol; National University of Ireland, Galway; NPL and the UK Met. Office 

Other areas of research include the development of equipment for monitoring a wide variety of other ozone precursor compounds, which play an important role in issues of public health and urban/rural pollution assessments. The group has also gained great expertise in the area of tracer release experiments. The transport and dispersion of pollutants has enormous implications for the environment on urban, regional and global scales. On urban scales, local emissions of pollutants can directly impact on the health of the inhabitants, while chemical changes and deposition during transport can have more widespread regional effects.