Paul Wennberg is the R. Stanton Avery Professor of Atmospheric Chemistry and Environmental Science and Engineering at the California Institute of Technology. He received his PhD in physical chemistry from Harvard in 1994. His research group studies atmospheric composition using laboratory, in situ, and remote sensing tools. He served as the first chair of the Total Carbon Column Observing Network (TCCON) and was a founding member of NASA’s Orbiting Carbon Observatory (OCO) project. He is a member of U.S. National Academy of Sciences and MacArthur Fellow.