The highest mountains on Earth are home to snow leopards, golden eagles, mountain goats, barnacle goslings, and gelada monkeys; only the toughest of animals can endure the extreme weather, scarce food supplies and limited oxygen on these peaks.
Fresh water is our most precious resource and it defines the distribution of life on land. Follow the descent of rivers from their mountain sources to the sea. Watch spectacular waterfalls, fly inside the Grand Canyon and explore the wildlife below the ice in the world's deepest lake. Witness unique and dramatic moments of animal behaviour: a showdown between smooth-coated otters and mugger crocodiles; deep-diving long tailed macaques; massive flocks of snow geese on the wing and a piranha frenzy in the perilous waters of the world's largest wetland.
The Taiga forest, on the edge of the Arctic, is a silent world of stunted conifers. The trees may be small but filming from the air reveals its true scale. A third of all trees on Earth grow here and during the short summer they produce enough oxygen to change the atmosphere.
Steve Backshall tries to discover just what makes it possible for a river to stop in the middle of a desert. The Okavango is the world's largest inland delta and home to a one of Africa's greatest congregations of wildlife, and in asking the difficult questions Steve reveals the astounding secret to its existence.