David Attenborough hosts this exceptional 12-part documentary series surveying   the planet in all its aspects. Co-produced by the BBC and Time-Life Video,       this series offers new insights into the wonders of the natural world.           Includes The Open Ocean, The Jungle, Sweet Fresh Water, The Northern        Forests, Seas of Grass, The Frozen World, The Margins of the Land, The Sky     Above, The Baking Deserts, Worlds Apart, The Building of the Earth, and