Mark played a leadership role in engaging American faith communities to address environmental issues. He served as the Founding Executive Director of the Coalition on the Environment and Jewish Life (COEJL) from 1994 to 2003. Under his leadership, COEJL grew from a short-term project of the National Religious Partnership for the Environment into a permanent coalition of 29 national Jewish agencies with affiliated institutions across North America. In addition to his organizational leadership, Mark is the author of many articles, chapters, and educational materials on Judaism and the environment. He has an MA in International Relations and Graduate Certificate in Development Studies from Yale University, and a BA in Sociology from the University of California, Santa Cruz.