"It is now clear that we face a deepening global climate crisis that requires us to act boldly, quickly, and wisely," quoth Al Gore. The big enchilada of environmental movies, "An Inconvenient Truth" brought global warming into the public consciousness in a major (and unexpected, and controversial) way. This big-screen call-to-action even won Gore and company a couple of Oscars - not bad for something that started out as one former vice president's PowerPoint presentation.
Credit: Paramount Classics