Huge asteroids have smashed into the earth, and turned it into an enveloped fire, uninhabitable to almost all life on the surface. The world will get hit again. It's just a matter of when. So, what should we do as a species? Should we just, like the dinosaurs, look up and die? The reasons the dinosaurs are extinct is they didn't have a space program. We do. We have the capability to perhaps escape the Earth.
Astronaut Chris Hadfield believes the only chance for human survival is to escape from Earth and build a space colony, but there are real barriers.

In the far north of our planet lies the largest land habitat on earth, home to snow-covered forests and the icy open tundra. These are lands of extremes that push animals to their limits: in winter they are so cold that much of the ground has remained frozen since the last ice age. To stand any chance of survival, animals must adapt in extreme ways: here a super pack of wolves, 25 strong, has come together to take on the only large prey available to them in winter, American bison.
On the featureless tundra, an Arctic fox must strike a living alone. She is a wanderer and will roam many hundreds of miles searching for tiny lemmings, hidden deep underground. The only way to reach them is with a head dive. In the remote far east of Russia, a rare Amur leopard prowls the seemingly empty, snow-covered forest. With little prey available, it must use its ingenuity to find a meal. It follows crows in the hope of finding carrion, but it must not stay long, for it shares the forest with a far larger but equally hungry big cat, the Siberian tiger.
As spring arrives, the forests begin to thaw and life returns. Beneath the ground, a nest of tiny painted turtle hatchlings now emerge, having remained frozen in a state of suspended animation throughout winter. To the north, it is a further month before the sun’s warmth baths the frozen ground of the tundra. Tucked away underground lies a tiny snow queen – a Lapland bumble bee. She is the sole survivor of her colony - the rest perished in the winter freeze - but her larger size, her furry body and antifreeze in her blood have allowed her to survive. Now she is in a hurry. She must feed herself and raise a brood in the brief window of summer while the flowers are in bloom.
Snowy owls also use the open tundra to breed: one pair have raised a nest full of fluffy chicks. With 24-hour daylight in which to hunt, the dedicated parents bring back meal after meal for their ever-growing brood. But one day, they return to find the nest empty.
Today, the biggest challenge in the tundra is climate change. Warming summers are melting the permafrost deep within the soil, causing the ground to thaw and, in places, the land to collapse. These changes are impacting the animals too. Caribou arrive in herds of 200,000 individuals to raise their calves in the rich pastures, but warming means mosquitos emerge sooner and bother the calves before they have had a chance to gain strength. The parents drive their young to cooler, mosquito-free land, but to get there they must cross rivers running with increased meltwater and escape hungry grizzly bears. They, like much of the tundra's wildlife, are adapted to live in the extremes - but the challenge of today’s warming climate could be one extreme too many.

In this captivating final episode of the series we meet some incredible conservation champions on nature's front line, fighting to preserve the future of our beautiful planet. The episode opens with a dramatic rescue operation for the critically endangered black rhino, showcasing the efforts of Dumi Zwane and his team to establish a new breeding colony in a safe haven. The focus then shifts to the Centro Jambatu research center in the Andes, where Jaime Culebras works tirelessly to save the last of certain frog species. The documentary also highlights the efforts of Trang Nguyen, who bravely infiltrates the illegal wildlife trade in West Africa to protect forest elephants from ivory poachers. Meanwhile, in Vienna, Katharina Huchler undertakes a remarkable journey to reintroduce the northern bald ibis to Europe after its extinction 400 years ago. Indigenous leader Alessandra Korap's battle to preserve the Amazon rainforest from exploitation is a key focus, alongside Mohamed Nasheed's fight against climate change to save coral reefs and his country.
This episode addresses the broader issue of habitat destruction, emphasizing its role as a primary driver of extinction. It poignantly demonstrates the interconnectivity of life on Earth and the critical importance of conservation efforts.

In the first episode, Sir David Attenborough reveals the unexpected wildlife riches of the British Isles, showcasing the dramatic and spectacular habitats that rival any across the globe. This journey uncovers the diversity of life in the UK's unique landscapes, from the intricate world of bumblebees to the swift lives of kingfishers. The episode captures extraordinary scenes of nature, including killer whales preying on seals, golden eagles in the Scottish mountains, the cunning tactics of woodland plants, and the perilous life of puffins evading gulls. It highlights Britain's geological diversity as a cornerstone of its natural wealth, contributing to an array of habitats and supporting a wide range of life.
Britain's importance extends to being a haven for migratory birds, with our seas feeding 65% of the world's gannets and supporting the largest colony of northern gannets on Scotland's Bass Rock. The west coast of Scotland offers sanctuary to barnacle geese due to its abundant food and mild climate, though they remain vigilant against hunting sea eagles. Despite these natural treasures, Britain faces challenges as one of the most nature-depleted countries globally. Sir David Attenborough emphasizes the need to conserve and restore these wild isles for the enjoyment and benefit of future generations.

We're transported to Atka Bay on the frigid coast of Antarctica, where a magnificent colony of emperor penguins embarks on a jaw-dropping journey. These remarkable birds, after three months of oceanic feasting, return to the frozen continent as the waters freeze over. What makes their story even more gripping is that they are the last inhabitants of Antarctica, as other wildlife has wisely retreated to the safer sea.
Narrated by David Attenborough, this extraordinary documentary immerses you in an epic saga of survival, fierce parenting, and unwavering tenacity. Join these resilient penguins as they confront the harshest conditions on Earth, embarking on an unforgettable adventure deep within the icy heart of the wilderness.