the final episode deals with plants that live in hostile environments. Attenborough visits Ellesmere Island, north of the Arctic Circle, to demonstrate that even in a place that is unconducive to life, it can be found. Algae and lichens grow in or on rock, and during summer, when the ice melts, flowers are much more apparent. However, they must remain close to the ground to stay out of the chilling wind. In the Tasmanian mountains, plants conserve heat by growing into 'cushions' that act as solar panels, with as many as a million individual shoots grouped together as one. Others, such as the lobelia in Mount Kenya, have a 'fur coat' of dense hairs on their leaves. The saguaro cactus in the Sonoran Desert flourishes because of its ability to retain vast amounts of water, which can't be lost through leaves because it has none. Many desert dwellers benefit from an accelerated life cycle, blooming rapidly within weeks after rainfall. Conversely, Mount Roraima is one of the wettest places on Earth. It is a huge sandstone plateau with high waterfalls and nutrients are continuously washed away, so plants have to adapt their diet if they are to survive. A bladderwort is shown invading a bromeliad. Inhabitants of lakes have other problems to contend with: those that dominate the surface will proliferate, and the Amazon water lily provides an apt illustration. Attenborough ends the series with an entreaty for the conservation of plant species.

Sagan discusses comets and asteroids as planetary impactors, giving recent examples of the Tunguska event and a lunar impact described by Canterbury monks in 1178. It moves to a description of the environment of Venus, from the previous fantastic theories of people such as Immanuel Velikovsky to the information gained by the Venera landers and its implications for Earth's greenhouse effect. The Cosmos Update highlights the connection to global warming.

The episode, devoted to the planet Mars, begins with scientific and fictional speculation about the Red Planet during the late nineteenth and early twentieth centuries (H. G. Wells' The War of the Worlds, Edgar Rice Burroughs' science fiction books, and Percival Lowell's false vision of canals on Mars). It then moves to Robert Goddard's early experiments in rocket-building, inspired by reading science fiction, and the work by Mars probes, including the Viking, searching for life on Mars. The episode ends with the possibility of the terraforming and colonization of Mars and a Cosmos Update on the relevance of Mars' environment to Earth's and the possibility of a manned mission to Mars.

Each year an unbelievable feeding frenzy takes place in the oceans of South Africa as billions of sardines migrate up the KwaZulu-Natal Coast. Wild Ocean captures spectacular breaching whales, feeding sharks, diving gannets, and massive bait balls inside and up close on the screen. The migration has provided an annual food source for both life in the sea and the people living along the African shores for countless generations. The film demonstrates how business, government, and the local people have joined forces to protect this invaluable ecological resource.
The film will delve audiences into an epic underwater struggle for survival and reveal the economic and cultural impact the migration has on the coastal communities. Wild Ocean is an explosive, symphonic documentary film about man and nature which captures one of natures greatest migration spectacles through the magic of IMAX.

Global warming, and how to combat it, has provoked intense debate, changed the way we see the planet and created headlines around the world. But when and how did scientists first discover global warming, why has it led to such furious debate? In this three-part series geologist Dr Iain Stewart presents a definitive guide to the history of climate change.
Battle Begins uncovers some of the great unsung heroes of climate change science, and introduces us to a secret organisation of American government scientists, known as Jason, who wrote the first official report on global warming as far back as 1979. By the late 1980s global warming had already become a serious political issue. It looked as if the world was uniting to take action. But it turned out to be a false dawn.

Dr Iain Stewart investigates the counter-attack that was launched by the global warming sceptics in the 1990s. At the start of the 1990s it seemed the world was united. At the Rio Earth summit the world signed up to a programme of action to start tackling climate change. Even George Bush was there. But the consensus didn't last.
Iain examines the scientific arguments that developed as the global warming sceptics took on the climate change consensus. The sceptics attacked almost everything that scientists held to be true. They argued that the planet wasn't warming up, that even if it was it was nothing unusual, and certainly whatever was happening to the climate was nothing to do with human emissions of greenhouse gases. Iain interviews some of the key global warming sceptics, and discovers how their positions have changed over time.