David Attenborough narrates a look at life on each of the seven continents, revealing how each distinct land mass has shaped the creatures found there and the many challenges faced by animals in a modern world dominated by humans. He begins with Antarctica, where Weddell seals grind back the ice with their teeth, colourful starfish carpet the seabed, huge colonies of king penguins crowd any ice-free land, and four-ton elephant seals fight for territory on the beach. However, the ocean here is warming - and with that comes an uncertain future