His research has spanned from ecophysiological and ecological studies of natural and urban systems through atmospheric trace gas studies and forensic science. Throughout his academic career, Jim has also focused on creating the facilities and organizational structures to advance interdisciplinary science and provide new opportunities for others. Jim's recent research projects have melded stable isotope analyses with process studies to investigate carbon and water cycles, climate changes, air quality in urban zones, humans and our diets and foods, and biomarkers in climate studies.