New York Times: The thick-lined drawings of the Earth, a factory and a house, meant to convey the cycle of human consumption, are straightforward and child-friendly. So are the pictures of dark puffs of factory smoke and an outlined skull and crossbones, representing polluting chemicals floating in the air. Which is one reason “The Story of Stuff,” a 20-minute video about the effects of human consumption, has become a sleeper hit in classrooms across the nation. The video is a cheerful but …