From the time he saw the Apollo 8 Earthrise photo, Marc McGinnes has been a champion for the planet. In the aftermath of the 1969 Santa Barbara oil blowout and spill that ignited the environmental movement, he organized the first Environmental Rights Day, on January 28, 1970, that led to the first Earth Day observances on April 22 of the same year.

He co-founded the Community Environmental Council, the Environmental Defense Center, the Peaceful Resolutions Institute and the Community Mediation Council. Since 1971, he has won numerous teaching awards as a faculty member of the Environmental Studies Program at the University of California, Santa Barbara.