"Narrated by Robert Redford" is always a promising credit to see at the beginning of a documentary, since it implies that whatever else happens, you'll get to listen to the sonorous tones of a handsome man. Ah, but Mark Kitchell's A Fierce Green Fire is playing a deeper (and probably more budget-friendly) game than that, as Redford only narrates the film's Act 1, subtitled "Conservation." Ashley Judd, Van Jones, Isabel Allende, and Meryl Streep take over talking chores for the next four Acts, as A Fierce Green Fire traces the evolution of environmentalism from the early conservationist movement up through the modern climate change controversy. There's a fair amount of preaching to the choir and recitation of familiar factoids, but the movie justifies its existence when it retells the all-but-forgotten Love Canal pollution debacle of the 1970s, a subject which deserves its own film. Also to its credit, the movie doesn't shy away from the infighting that seems to constantly derail the movements, be it the Sierra Club or Greenpeace. A Fierce Green Fire shows environmentalists as flawed and often deeply hubristic people who aren't above spray-painting a seal pup as a means to an end — especially if that end is to save the planet.