Saw two powerful representations of the melting Arctic ice world recently: multimedia performer Cynthia Hopkins' "This Clement Earth," at St. Ann's Warehouse, and the film "Chasing Ice," a documentary about the photographer James Balog. Both try in their ways to make the enormity of climate change real to us, a challenge because the scale is so great we can't fit ourselves into a picture of it, certainly not ourselves as agents. Balog and his team use photography to create time lapse sequences of the alarming thinning and retreating of glaciers - and some live footage of enormous calvings (some of which you've seen). It's a heroic struggle against the elements to assemble scientific proof, and also exquisitely beautiful, very close to the paralysis of the sublime. Hopkins takes a different approach. She incarnates three unlikely figures to talk to us: the shade of a Cheyenne girl, murdered at the Sand Creek massacre of 1864, mutely foreseeing our civilization's collapse. An extraterrestrial who has taken the form of a goofy good ol' boy to tell us how lucky we are to be at one of those rare moments where a planet supports us, and to have the chance to do something to keep it that way a little longer. And a woman from 300 years in the future come back to sing hippie songs urging us keep doing the things that make her post-civilization world possible, where all signs of industrialization are long gone and New York City is seen through the bottom of a boat. The hokeyness of it all stops short of heavy-handedness (except in the dead Indian) and manages somehow both to capture the staggering scale of the crisis and maintain some hope that human ingenuity might do something. (The Greenland pic above's from somewhere else again.)