This stir-it-upper from director Davis Guggenheim is basically a lecture by Al Gore about global warming, including a multimedia slide show and shots of the former veep on the road, giving speeches and plugging thoughts into his Apple computer on environmental issues that have obsessed him for two decades. Dull? Not a bit. It grabs you like a thriller with an ending that will haunt your dreams. Gore keeps us riveted by being charming, literate and profoundly persuasive on a topic that’s scarier than anything in a dozen Japanese horror flicks. Vote Gore on this one.