From a Columbia Journalism Review story by Mark Hertsgaard and Kyle Pope headlined “Earth Day, and the media’s point of view”:

ON THE FIRST EARTH DAY, in 1970, America’s TV networks were not shy about taking a position on the news of the day. CBS News produced a special titled “Earth Day, A Question of Survival,” which opened its flagship evening broadcast showing biologist Barry Commoner telling a crowd, “This planet is threatened with destruction…. We are in a crisis of survival.” Anchorman Walter Cronkite then reiterated the theme, declaring this a “unique day in American history, dedicated to mankind seeking its own survival.” ABC News titled its own special report, “Earth Day: An SOS for Survival.” Anchorman Frank Reynolds’ first sentence congratulated activists for speaking out, crediting “millions of Americans” with taking “the first step to survival.”