Interesting Q&A from Mother Jones magazine on a group of documentarians (working on a film called "Melting Planet") wrestling with the question of how to bring the issue of global warming home. No one has yet found a simple but effective image to tell the story (though plenty are looking).
The crucial quote:
On a sort of parallel track we’ve also talked to people about finding the “crying Indian” for global warming–the “crying Indian” being a TV advertisement about littering where a Native American dressed in native garb was standing by the side of a highway with cars speeding by and a bag of garbage gets tossed out, lands at his feet, and the camera pans up to show this tear coming down his cheek. It was a very effective thing, so part of our fascination with the messaging about global warming is the inability for anybody to have really come up with a “crying Indian” yet.