For years, big business -- from oil and coal companies to electric utilities to car manufacturers -- have resisted change to environmental policy and stifled the debate over climate change in America and around the globe. Now, facing rising pressure from governments, green groups and investors alike, big business is reshaping its approach to the environment. With the election looming, FRONTLINE producer Martin Smith investigates what some businesses are doing to fend off new regulations and how others are repositioning themselves to prosper in a radically changed world.