A good friend of mine has just turned green. But it wasn’t The Great Warming or An Inconvenient Truth that did the trick, but Robert F. Kennedy’s Crimes Against Nature.

I bring it up because this friend is well-read, intelligent, and politically liberal; he has certainly been exposed to all the same evidence that won other people over long ago. And yet until now, the only time the word “environmentalist” issued from his mouth was when he was teasing me about being one. RFK’s book — with its contrast of political and corporate greed on one hand and democracy-driven environmental stewardship on the other — spoke my friend’s language … and now he won’t shut up about tragedies against the commons and government-subsidized pollution.

It’s rather funny to watch someone truly get for the first time something others been ranting about for ages. And although I’m kind of embarrassed to admit it, my own “aha!” was not so long ago: it honestly wasn’t until seeing An Inconvenient Truth this past summer that I truly grasped the urgency of global warming.

Once you are tuned in to climate change, pollution, and biodiversity loss, of course, you find yourself awash in a sea of damning evidence. (It’s similar to the experience of learning a new word and suddenly hearing it everywhere.) The sea might make it hard for some to remember a single moment of enlightenment, if indeed one occurred.

Nonetheless, it remains an interesting question — it reminds us that our message must be not singular but an array of appeals to our equally varied interests: social duty, morality, and spirituality, but also social status, economic well-being, and competitiveness.