
Fifty years ago today, millions gathered in demonstrations, teach-ins, and community-cleanups, with words and deeds demanding a more sustainable future. The first Earth Day marked the beginning of the environmental movement, and it achieved results. The Clean Air Act and the Environmental Protection Agency were established, leading to cleaner air and water for all of us. To reflect on five decades of environmental change, a group of friends and colleagues led by Philippe Tortell (with whom I went to graduate school) wrote a series of essays, released as a book today.