Two narratives -- the life cycle of a mother walrus and her calf, and the life of a polar bear and her cubs -- are used to illustrate the harsh realities of existence in the Arctic.

Siberian gulag escapees travel four thousand miles by foot to freedom in India.

Fifty years ago there were close to half-a-million lions in Africa. Today there are around 20,000. To make matters worse, lions, unlike elephants, which are far more numerous, have virtually no protection under government mandate ...

A team of storm chasers track a tornado.

A journey into the land of sharks. The old myth of swimming killing machines is put against the true nature of those rather peaceful hunters, whose evolution ended in biological perfection millions of years ago. We accompany exped...

Volcanoes, earthquakes, and tornadoes all can cause enormous damage, and predicting where and when they will strike is of great importance. Volcanologist Dr. Marie Edmonds has devised sensors that monitor the underground activity of magma to better predict future eruptions on the Caribbean island of Monserrat, the site of the massive 1995 eruption captured for this film. Geophysicist Dr. Ross Stein studied the earthquake repair records in Istanbul's Hagia Sophia over the centuries to find clues about the history of earthquakes in Turkey. He discovers a pattern in quakes along the long North Anatolian Fault system, including the massively destructive quake at Izmit in 1999, and predicts the next earthquake just a few miles south of Istanbul. Dr. Joshua Wurman and his team chase tornados in trucks equipped with Doppler radar in an attempt to probe the interior of a tornado just as it is born.

At the end of each Antarctic summer, the emperor penguins of the South Pole journey to their traditional breeding grounds in a fascinating mating ritual that is captured in this documentary by intrepid filmmaker Luc Jacquet. The journey across frozen tundra proves to be the simplest part of the ritual, as after the egg is hatched, the female must delicately transfer it to the male and make her way back to the distant sea to nourish herself and bring back food to her newborn chick.