This article examines the possible contributions the existentialist tradition might make to environmentalism. I note, first, that Martin Heidegger is a questionable ally, both because his relationship to technology is ambiguous, while his affiliations with the Nazis were not. But the larger existentialist tradition is valuable for the environmental movement because it opens up a field of possibilities for human creativity. Sartre serves as exemplary for the way he struggled with the dialectic between individual autonomy in his early philosophy of (...) freedom, and the needs of the collective as he confronted them in his later turn toward Marxism. But the demands of the collective are more reasonably confronted in the larger legacy of Hegel than in the more limited form they took in Sartre's Marxism. The article concludes that Sartre's struggles can be enlightening to those of us who now seek the joyful wisdom of existential freedom for the individual even as we confront the demands that environmental degradation will place on the collective. (shrink)