Hi, I’m Keanu Reeves.” “And I’m Alanis Morissette.” With those eight words, this global-warming documentary stakes its claim to credibility. Harnessing its narrators’ star power as if it were a new source of alternative energy, director Michael Taylor’s call to arms fights the changing climate and an apathetic populace with slick production values and raw force of earnestness. Made as a three-part series for Discovery Channel Canada, the 80-minute doc covers lots of ground with little depth, whizzing from fossil fuel dependency to increasingly catastrophic storms to the emergence of China and India as insatiable energy consumers. The tone is pure eighth-grade AV-club infotainment, bolstered by silly animated graphics, a tarot reader predicting Katrina, oddly integrated profiles of imperiled Peruvian families and Louisiana zydeco musicians, and the requisite sped-up footage of city traffic to show life out of balance. It would have been nice to hear one skeptical voice, if only for the film to refute it.