Rivers provide the essentials of life: fresh food and water. They often provide natural highways and enable us to live in just about every environment on Earth. But rivers can also flood, freeze or disappear altogether!Cities - Surviving the Urban Jungle Human Planet joins Sam Niang, a Laotian fisherman, as he walks a high wire strung above the raging Mekong River rapids on an extraordinary commute to work. There's also a look at the remarkable partnership between Samburu tribesmen and wild elephants in their search for water in the dried-out river beds of Northern Kenya. Plus, a father who must take his two children on a six-day trek down a frozen river - the most dangerous school run on Earth, and the ice dam busters of Ottowa with their dynamite solution to a city centre hold-up.

As almost all animal inhabitants of Antarctica are forced to migrate north, the sea underneath the frozen ice still provides a home to many specially adapted fish whose cells are protected from freezing through an 'antifreeze' liquid. Many of them feed on the faeces of other animals. The most notable larger animal that does not migrate north is perhaps the Weddell Seal, which can be found as close as 1300 kilometres to the pole. Groups of seals tear holes into the ice to dive for food and come up to breathe. The females come back to the ice to give birth. This episode also describes primitive plant life such as lichen, which can still be found on the continent in winter, even in the extremely dry and permanently frozen valleys conditions under which dead animals can lie frozen for many centuries without decomposing. It details the life of the Emperor Penguin, 'the only birds to lay their eggs directly on ice'. While other animals retreat, Emperors migrate not just to the ice, but into the Antarctic continent. The females lay eggs which are incubated by the males under the harshest conditions on Earth (huddling closely together for warmth), while the females return to the sea.

Brian explores the physics of the size of life through some close encounters with Australia's wildlife. From swimming with great white sharks to tracking red kangaroos, he discovers that the size you are profoundly affects the life you lead and, ultimately, how long you have to enjoy it.

'Mormon Lost Boys' Young men have been thrown out of their homes because of an edict allowing polygamist church elders to monopolize young girls. 'The Fat Farms of Mauritania' In the West African country of Mauritania, parents send their daughters to rural fattening camps. 'Mumbai Slumscraper' A visit to Mumbai, where slums sit below billion-dollar, single-family skyscrapers.

A visually stunning journey to the end of the world with the hardy and devoted people who live there year-round. The research stations scattered throughout the continent host a close-knit international population of scientists, technicians and craftsmen. Isolated from the rest of the world, enduring months of unending darkness followed by periods when the sun never sets, Antarctic residents experience firsthand the beauty and brutality of the most severe environment on Earth. Capturing epic battles against hellacious storms, quiet reveries of nature's grandeur, and everyday moments of work and laughter, this unique documentary shows a steadfast community thriving in a land few humans have experienced. Using specially modified cameras and spectacular time-lapse photography, filmmaker Anthony Powell captures the splendor of the region like no film before. ANTARCTICA: A YEAR ON ICE gives testament to the planet's natural wonders, humanity's thirst for adventure, and the emotional extremes that accompany a year within the last pristine wilderness on the planet.

'Deliver Us from Drought' - Over the past years, Texas has experienced the worst drought in its recorded history. 97% of the scientific community agrees that human activity has contributed to extreme weather patterns around the world. But many Texans--legislators, community leaders and citizens--don't attribute their drought to humans, and have taken few if any initiatives to limit the state's CO2 emissions, currently the highest in the country. "The Resource Curse" - As humanity's appetite for energy grows exponentially, the extraction industry scrambles to the most remote regions on Earth. In the undeveloped Melanesian country of Papua New Guinea, America's Exxon Mobil has staked its claim to a $19 billion liquid natural-gas project. While some see Exxon's mammoth presence as the catalyst that will usher the underdeveloped country into the 21st Century, others predict the initiative could plunge its people into civil war.