For an issue-oriented doc with activist aims, the line between hope and despair — between placating an outraged audience and calling it to action — is a fine one, indeed. Any indie auteur feels tempted to salute grassroots heroism, his own not least, although the promise of "making a difference" can't be fulfilled before the doc is over, lest it let us off the hook. At the other extreme, pessimism can work paradoxically to inspire, in part through its implicit flattery. (Only you can prevent forest fires!) But it can also backfire: When Leo DiCaprio goes so far as to predict the extinction of humanity in his admirably bleak... More >>>