n. Worry or agitation caused by concerns about the present and future state of the environment.
Of all science fiction's apocalypses, John Christopher's 1956 The Death of Grass is one of the most haunting. Its premise — a virus that wipes out the world's grasses, and hence most cereal crops — is simple; its account of the ensuing disaster gripping. As a reminder of the awful necessity of the things one takes for granted, it is hard to beat.

Christopher's novel came strongly to mind as I read some of the gloomier passages of Colin Tudge's new book. This was not because these passages seemed like science fiction — there is, after all, enough eco-anxiety around at the moment to make all but the direst predictions seem routine — but because of their stark emphasis on the perils of taking food for granted.
—Naville Hawcock, “Growth spurt,” Financial Times, April 14, 2007
Still, automakers should be worried. The latest sales figures from Britain—Europe's largest SUV market—show demand down 6 percent over the past year. Soaring petrol prices offer some explanation, but the true cause has more to do with the vehicle's questionable image in an age of deepening eco-anxiety.
—William Underhill, “When Is Big Too Big?,” Newsweek, December 18, 2006
1990 (earliest)
Long before eco-anxiety became a national ailment this year, a strong environmental ethic seemed to come naturally to people in Anne Arundel.
—Lisa Leff, “Ecology Carries Clout in Anne Arundel,” The Washington Post, August 05, 1990