In James Cameron's 2009 film "Avatar," which takes place almost entirely on the distant planet of Pandora, several characters make passing mention that life on Earth is squalid. The implication is that poor resource allocation and rampant pollution has made our world intolerable, making it a striking contrast to the placid, glowing forests of the alien planet. It wouldn't be until an extended DVD director's cut of "Avatar," however, that life on Earth would be actually depicted on screen....