Along the way, it features the journeys made by three particular species—the polar bear, African bush elephant and humpback whale—to highlight the threats to their survival in the face of rapid environmental change.
A companion piece and a sequel to the 2006 BBC/Discovery/NHK/CBC television series Planet Earth, the film uses many of the same sequences, though most are edited differently, and features previously unseen footage not seen on TV.
[5] Over the course of a calendar year, Earth takes the viewer on a journey from the North Pole in January to the South in December, revealing how plants and animals respond to the power of the sun and the changing seasons.
Starting in the high Arctic in January, as the darkness of winter gives way to the sun, a mother polar bear is shown emerging from her den with two new cubs.
The herd times its arrival at the Okavango Delta to coincide with seasonal floodwaters which transform the desert into a lush water world.
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.
By October they enter polar waters, and by December the Antarctic sun has melted the sea ice to form sheltered bays.
The supporting cast of animals include mandarin ducklings filmed jumping from their tree hole nest, Arctic wolves hunting caribou, cheetah hunting Thomson's gazelle, elephants charging at white-backed vulture, birds of paradise displaying in the New Guinea rainforest, Adelie penguins in the Antarctic and demoiselle cranes on their autumn migration across the Himalayas.
In the Arctic, rising temperatures are causing a greater area of sea ice to melt and threatening the polar bear with extinction as early as 2030.
In February 2005, BBC Worldwide pre-sold distribution rights to Gaumont in France, Wanda Vision in Spain, and Frenetic Films in Switzerland.
[8] After this initial acquirements, Earth received its world premiere at Spain's San Sebastián International Film Festival in September.
For unknown reasons, Lionsgate never released the film in the US as originally intended, and in April 2008, the North American distribution rights to Earth were acquired by Walt Disney Studios.
Walt Disney Studios Motion Pictures also acquired distribution of the film in Canada, Italy and Latin American countries as well.
In January 2008, the Japanese version of Earth, narrated by actor Ken Watanabe, knocked Hollywood blockbuster I Am Legend off the top of the box office despite opening on half the number of screens.
Its worldwide total of $108,942,691 made Earth a commercial success and placed it second on the all-time list of highest-grossing nature documentaries, behind March of the Penguins.