Over the course of a calendar year, Earth takes the viewer on a journey from the North Pole to the South, revealing how plants and animals respond to the power of the sun and the changing seasons. The film focuses on three particular species, the polar bear, African elephant and humpback whale. In the high Arctic, as the darkness of winter gives way to the sun, a mother polar bear is shown emerging from her den with two new cubs. She needs food and must lead her cubs to her hunting ground on the sea ice before it begins to break up. By April, the sun never sets, and by August all the sea ice has melted. The mother and cubs have retreated to dry land, but a male polar bear is trapped at sea and must seek out land by swimming. He reaches an island with a walrus colony but is too exhausted to make a successful kill. He dies from injuries sustained in a walrus attack. African elephants are filmed from the air as they negotiate a dust storm in the Kalahari Desert. June is the dry season and they must follow ancient paths passed down through generations to reach watering holes. A mother and calf are separated from the herd in the storm but manage to reach shelter. The matriarch leads the herd to a temporary watering hole, but they must share it with hungry lions. The lions are shown attacking a solitary elephant at night, when their superior vision gives them the upper hand. The herd times its arrival at the Okavango Delta to coincide with seasonal floodwaters which transform the desert into a lush water world. A humpback whale mother and calf are filmed from the air and underwater at their breeding grounds in the shallow seas of the tropics. There is nothing here for the mother to eat, so she must guide her calf on a 4,000-mile (6,400 km) journey south to the rich feeding grounds near Antarctica, the longest migration of any marine mammal. En route, they negotiate dangerous seas where great white sharks are filmed breaching as they hunt sealions, and sailfish and dolphins combine to bait a shoal of small fish. By October they enter polar waters, and by December the Antarctic sun has melted the sea ice to form sheltered bays. Here, the whales are shown feeding on krill by trapping them in bubble nets.
«Absolutely thrilling, don't miss it!»
- Teri Hart, The movie network / family channel