I watched this movie for an art history class and it’s considered an important movie politically due to environmentalist message. At the time environmentalism wasn’t basically movie short-hand for, “this is a black and white moral conflict obviously the environmentalists are the good guys” though obviously that’s how they are portrayed in the Silent Running. There’s was also a popular environmentalist book call Silent Spring, that was incorporated into the movie’s name.
Also shut up Joan Baez is the shit.