Dr Stephens has research interests in tropical palaeoclimate, tropical geomorphology, geoarchaeology and geoconservation. Much of his work is focussed on reconstructing past environments and climatic change from sediments associated with human activity in order to shed light on human–environment interactions. He has used stable isotope analysis and soil micromorphological evidence to tease out climatic and environmental information, and OSL dating to determine the timing of change. He is also interested in the conservation of geologically important heritage sites in the Pacific. Most of his research has been undertaken in the humid tropics of Sarawak (Malaysian Borneo) and Fiji although he has also worked in the United Kingdom, the Ukraine, Armenia and Finland
