As co-directed by Mark Linfield and Alastair Fothergill, and narrated by the eminent Patrick Stewart, the nature documentary Earth represents an edited-down version of the 12-hour small-screen miniseries Planet Earth, reslated for cinematic release. The program provides a sweeping, 99-minute tour of our home planet's biosphere -- spanning every level of gaze, from the epic (crystal-clear shots of the Earth hovering in space) to the hyper-specific (a mother polar bear and her cubs waking from a lengthy period of hibernation). The film almost exclusively emphasizes the behavior of the animal populations that inhabit the Earth, yet carefully omits shots that depict the more gory predatory behavior of species, rendering it family-friendly. It also employs a chronological approach -- beginning in January in the Arctic wilderness, and moving progressively through the four seasons and 12 months comprising a single year, until it hits late December -- contrasting various geographic regions of the Earth as shot in various seasons. Above all else, a cautionary message underscores this footage; as in An Inconvenient Truth, the filmmakers continually remind their audience that despite the grandiloquence present onscreen, all may be lost if humankind is not careful.