Tolbert conducted research at Stanford Research Institute before joining the faculty of University of Colorado Boulder in 1991, teaching environmental chemistry courses to nonscience majors from 1992 to 2006. She was awarded Distinguished Professor in 2010. She is a Fellow and Associate Director of the Cooperative Institute for Research in Environmental Sciences, a joint venture between University of Colorado Boulder and National Oceanic and Atmospheric Administration.
Her research focuses on study of atmospheric chemistry, in particular polar stratospheric clouds and planetary atmospheres. She co-authored the book "Stratospheric Ozone Depletion" with Ann M. Middlebrook. She was featured in the book "I Want to be an Environmentalist".