I don't talk a lot about Earth Day here at Zooglobble, not because I hate the Earth ("dude, what a loser planet that is") but because much of the Earth Day-related music that crosses my desk is dull, tuneless, and/or unbearably preachy.
One of the exceptions is Uncle Rock's "There Is No Away," a graceful waltz about the permanence of trash featuring stringed accompaniment and Elizabeth Mitchell. I suppose Robert could sing the classifieds accompanied by strings and Elizabeth Mitchell and and I'd probably write about it here, but the gracefulness of the song helps keep it away from the "unbearably preachy" camp. (It fits well within the big picture of the latest Uncle Rock album, er, The Big Picture, which has a few more songs with an environmental awareness.)
Even better, for a limited time, you can download the mp3 for free from Uncle Rock's homepage. Mp3s are mostly waste-free after all (more so, I suppose, if you're solar-powered).