Spring arrives in the polar regions, and the sun appears after an absence of five months; warmth and life return to these magical ice worlds - the greatest seasonal transformation on our planet is underway.

Polar animals race to rear their young during times of plenty under the midnight sun.

The Arctic is the harshest environment on Earth: little food grows, it's dark for months on end, and temperatures stay well below freezing for much of the year. Yet four million people manage to survive here.

A look at the one environment that's been made by us for us - the city. Over half of the world's population now lives in the urban jungle. The city is built to keep untamed nature out - but nature can't be pushed away. From bed bugs sucking our blood at night to rats in our restaurants, many animals have adapted to a life with us.

In the second episode of Human Planet, we discover how the eternal quest for water brings huge challenges - and ingenious solutions - in the driest places on Earth.

Grasslands feed the world. Over thousands of years, we humans have learned to grow grains on the grasslands and domesticate the creatures that live there. Our success has propelled our population to almost seven billion people.

The rainforest is home to more species of plants and animals than any other habitat on the planet. But for humans, life there is not as easy as it looks. Life in the trees requires great skill, ingenuity and sheer bravery.

From lush cloud forests to bare summits that take your breath away, the higher you climb the tougher life gets on a mountain. Human Planet explores the extraordinary ways in which people survive at extreme altitudes where nature becomes utterly unforgiving.

As an air-breathing animal, the human is not built to survive in water. But people have found ways to live an almost aquatic life so they can exploit the sea's riches. From a 'shark-whisperer' in the Pacific to Brazilian fishermen collaborating with dolphins to catch mullet, this journey into the blue reveals astonishing tales of ingenuity and bravery.

Ragnar Axelsson, known as Rax, is a photograher for Iceland's largest newspaper. This documentary follows him on his life's mission, to capture the human faces of climate change by photographing the vanishing lifestyles of the people of the north.

In Africa, a family of chimps trapped in a lost world face a daily ... In a twist of fate, the last babies born into the gorge family have all been males. …

Pure white lemurs called silky sifaka live in the remote rainforests of Madagascar. They are one of the rarest animals in the world.

Every year grizzly bear families in North America depend for their survival on a spectacular natural event: the return of hundreds of millions of salmon from the Pacific Ocean to the mountain streams where they were born. The salmon travel thousands of miles to spawn and then die.

Stephen Fry loves Louisiana. Four months after the BP oil spill, dubbed the worst ecological disaster in the history of America, Fry returns to the Deep South together with zoologist Mark Carwardine, to see what the impact has been on the people, the vast wetlands and the species that live there.

How Yellowstone's Indian tribes were displaced to create this great American wilderness.

The final part of the series exploring how climate change is affecting the natural world.

"Life in the Freezer" is an exciting new natural history of the Antarctic. Less celebrated than its northern equivalent, it boasts an equal blend of extraordinary wildlife and stunning scenery. In this book, Alastair Fothergill traces the region's seasonal cycle and explains how marine, mammal, bird and plant life survive in one of the harshest climates on earth