John has been a member of the Geography Department at Maynooth University since 1978. He received his B.Sc. from the University of Glasgow in 1974 and also his PhD in the Meteorology and Climatology of Air Pollution from there in 1980. Over the intervening 42 years John has taught courses in climatology, biogeography, geomorphology and environmental resource management at Maynooth University and a number of universities in North America and Africa. He has published over 100 scientific papers and authored/ edited/co-authored 4 texts on various aspects of climatology and climate change in Ireland. He has served as President of the Irish Meteorological Society, the Geographical Society of Ireland and An Taisce, the National Trust for Ireland. He has been Editor, Treasurer, Secretary of several national associations as well as being the Irish representative on a number of European academic bodies. He has been involved in a number of international research projects and has led a number of nationally funded research projects examining various aspects of climate change in Ireland.
John contributed to the reports of the Intergovernmental Panel on Climate Change, which was awarded the Nobel Peace Prize in 2007. He is also a regular contributor to print and broadcast media on matters related to climate change science and policy and received the inaugural award for achievements in journalism from the European Meteorological Society in 2014.