This NY Times article is one of the best pieces I've read in the popular media on the social psychology of sustainable living.
"...what would be the point [of changing my lifestyle to reduce my environmental impact] when I know full well that halfway around the world there lives my evil twin, some carbon-footprint doppelgänger in Shanghai or Chongqing who has just bought his first car [...], is eager to swallow every bite of meat I forswear and who’s positively itching to replace every last pound of CO2 I’m struggling no longer to emit. So what exactly would I have to show for all my trouble?"If you've ever asked, or been asked, the "why bother?" question, this well-written piece from an expert in the field (Michael Pollan) is worth the five minutes it will take to get through it. Make sure you read all four pages; some of the best stuff, about the kinds of actions that make a difference and why, is near the end.