Philip Stevens, Rudy Professor and former chair of the Environmental Science Faculty Group. Before joining IU, Stevens was a postdoctoral research associate in atmospheric chemistry at The Pennsylvania State University, working on the development of instrumentation for the measurement of atmospheric free radicals.

Stevens's research is focused on the characterization of the chemical mechanisms in the atmosphere that influence indoor air quality, regional air quality, and global climate change. His current research is focused on improving our understanding of the influence of biogenic emissions and their oxidation products on the chemistry of the atmosphere.

He received a B.A. in chemistry from Oberlin College and a Ph.D. in physical chemistry from Harvard University.