Polar bears are challenged by global warming in the Disney documentary Earth. (Buena Vista Pictures)Before the opening credits even began for Earth, the first film from the new, eco-friendly Disneynature label, there was a short prologue, reminding the audience of Disney's history as a maker of nature films, ranging from Bambi (1942) to the Academy Award-winning True-Life Adventures series of the 1940s and '50s.

Disney's Earth serves as an update to those old nature docs put forth by Uncle Walt. Now, the loving, awe-inspiring footage is accompanied by the darker message that time and resources are running out.

Earth strives to recapture those glory days, but it is put in the interesting position of arriving in theatres on Earth Day 2009, and on the heels of An Inconvenient Truth (2006), Al Gore's urgent, minutes-to-midnight documentary detailing the catastrophic effects of global warming. In this way, Earth serves as an interesting update to those old nature docs put forth by Uncle Walt, or even Canada's own Hinterland Who's Who clips. Now, all of the loving, awe-inspiring footage is accompanied by the darker message that time and resources are running out.

Accordingly, James Earl Jones has been brought on board to act as omniscient narrator. His warm baritone voice has great gravitas (he was once Darth Vader, after all), and within minutes, he gravely notes that Earth is getting warmer, and the Arctic landscape where we see a mother polar bear frolicking with her klutzy cubs is melting a little quicker each year. This message is introduced gently at first, but becomes increasingly urgent as the film progresses and cracking ice places one of the polar bear clan in jeopardy.

These cuddly Arctic critters serve as the start and end brackets for Earth, and help to provide the documentary with its bare-bones plot, which centres on a trio of animal families (the bears, a humpback whale with her calf, and a mother and baby elephant) all struggling to survive in treacherous environments, where peril is never far off thanks to the surrounding harsh elements and hungry predators.

The little tots at the screening I attended ooh-ed, aww-ed and giggled at the admittedly adorable polar bears, and went bananas (quite rightly) at a scene involving baby ducks attempting their first flight in glorious slo-mo. Special mention should also go to the scene-stealing tropical bird of paradise, whose vibrant mating strut (accompanied by James Earl Jones' hilarious, "Get down, baby!" narration) brought the house down. But the wee audience around me seemed to grow restless in heavier sequences involving elephants in peril, and I spied at least one rug rat hiding his face in his mother's arm when it came time for a cheetah to bear down on its young, gazelle prey.

A family of African elephants survive in Namibia's Kalahari Desert. (Buena Vista Pictures)Thankfully, Earth manages to cut away from most of the gruesome, Darwinian realities of the animal kingdom, and the majority of the film is a majestic celebration of life in the wild. As the title implies, the film has a lot of ground to cover, starting in the far north of the Arctic, then wending its way slowly southwards, passing through the locations as diverse as the Broadleaf Woodlands of the Americas, the Kalahari Desert, some New Guinea rainforests, and the Himalayas before it finally arrives, a year later, in Antarctica.

Along the way, the filmmakers (taking a reported 60 per cent of their footage from the acclaimed BBC Planet Earth series) offer up a breathtaking array of images: Earth is jaw dropping in its beauty. It's tricky to single out just one stunning scene – aerial shots that make sand dunes look smooth as ice cream, time-lapse sequences of flowers piercing the soil and then blooming, cranes that float like hang-gliders on the wind, and a curiously balletic shot of a great white shark lunching on a sea lion in mid-air are just a few of the standouts.

The film is far less graceful in its narration – I found myself longing for some of the tighter, more gripping storytelling flourishes from March of the Penguins (2005). As Earth trots across the globe, the central image of the sun is used to link the disparate locations together, with sometimes shaky results. As well, the film’s occasionally heavy-handed lines, including a reference to the "circle of life" and a final speech that sounds strangely reminiscent of the "children are the future" line from Whitney Houston's The Greatest Love of All, veer dangerously close to being outright hokey.

Still, these are minor quibbles with an otherwise gorgeous film, and who can really resist a movie featuring floating baby ducks? Certainly not the enraptured youngsters sitting around me. I'm still not sure they completely grasped the notion of melting polar ice caps, but somehow, I think the film's more explicit message – that our planet is something astonishing that's worth saving – came through loud and clear.

Earth opens across Canada on April 22.

Lee Ferguson writes about the arts for CBCNews.ca.