Let's have a song lyric contest! Here's how it would work. You take a well-known, existing song, and subtly (or not so subtly) change the lyric to reflect an eco-theme of some sort. Mad Magazine used to feature take-offs on lyrics all the time. It was fun! Here's part of one to start.

Unsustainable 

(to be sung to the tune, 'Unforgettable')

Unsustainable, that's what we are.
Unsustainable, both near and far.
Like an ad for stuff, that sings to us,
How the lust for more does things to us.
Never before - have we been more

Unsustainable in every way.
There's always more, that's what we say.
That's why we're getting unmaintainable,
Our way of life, unsustainable...
That's why I'm feelin' I'm unsustainable too.