National Geographic photographer James Balog, acclaimed for his work on vanishing animal species, goes for even mightier concerns in this valiant documentary: to provide irrefutable visual evidence of the magnitude of man-made global warming. Chasing Ice takes Balog to the far north, where he plants 25 time-lapse cameras in the deep snow of Iceland and Greenland. And what he captures on camera is horrific and even tearful: mighty glaciers eroding, collapsing before our eyes, sending melting ice and waters southward. And, lo, here comes Hurricane Sandy, pushing those now-bulging coastal waters onto land! Will anyone but the usual converted consider director Jeff Orlowski's urgent film? Or, hopefully, will the ravages of Sandy bring a new audience of alarmed Americans flooding to Chasing Ice?