It is high summer in the Polar Regions, and the sun never sets. Vast hordes of summer visitors cram a lifetime of drama into one long, magical day; they must feed, fight and rear their young in this brief window of plenty. Summer is a tough time for the polar bear family, as their ice world melts away and the cubs take their first swimming lesson. Some bears save energy by dozing on icy sun beds, while others go egg-collecting in an Arctic tern colony, braving bombardment by sharp beaks. There are even bigger battles on the tundra; a herd of musk oxen gallop to the rescue as a calf is caught in a life and death struggle with a pair of Arctic wolves. But summer also brings surprises, as a huge colony of 400,000 king penguins cope with an unlikely problem - heat. The adults go surfing, while the woolly-coated chicks take a cooling mud bath. Nearby, a bull fur seal is prepared to fight to the death with a rival. Fur flies as the little pups struggle desperately to keep out of the way of the duelling giants. Further south, a minke whale is hunted amongst the ice floes by a family of killer whales. The dramatic chase lasts over 2 hours and has never been filmed before. The killers harry the minke whale, taking it in turns to wear it down. Eventually it succumbs to the relentless battering. Finally, comical adelie penguins waddle back to their half a million strong colony like clockwork toys. The fluffy chicks need constant feeding and protection as piratical skuas patrol the skies. When an unguarded chick is snatched, a dramatic "dogfight" ensues.

For the animals in the polar regions, autumn means dramatic battles and epic journeys. Time is running out - the Arctic Ocean is freezing over and the sea ice is advancing at 2.5 miles per day around Antarctica. Polar bears gather in large numbers on the Arctic coast as they wait for the return of the ice. Soon, tempers fray and violent sparring contests break out. Meanwhile 2,000 beluga whales head for one special estuary, a gigantic 'whale spa' where they will thrash their snow-white bodies against the gravel and exfoliate. Inland, the tundra undergoes a dramatic transformation from green to fiery red. Here, musk ox males slam head-first into each other with the force of a 30mph car crash as they struggle to defend their harems. Frisky young caribou males play a game of 'grandma's footsteps' as they try to steal the boss's female. Down in Antarctica, Adelie penguin chicks huddle together in creches. When a parent returns from fishing, it leads its twins on a comical steeplechase - sadly there's only enough for one, so the winner gets the meal. Two months later and the chicks are fully feathered apart from downy Mohican hairdos - they're ready to take their first swim - reluctantly though, as it seems penguins are not born with a love of water! And with good reason - a leopard seal explodes from the sea and pulls one from an ice floe, a hunting manoeuvre that has never been filmed before. As winter approaches and everyone has left, the giant emperor penguin arrives and makes an epic trek inland to breed. The mothers soon return to the sea leaving the fathers to hold the eggs and endure the coldest winter on earth.

Sir David Attenborough journeys to both Polar Regions to investigate what rising temperatures will mean for the people and wildlife that live there and for the rest of the planet. David starts out at the North Pole, standing on sea ice several metres thick, but which scientists predict could be Open Ocean within the next few decades. The Arctic has been warming at twice the global average, so David heads out with a Norwegian team to see what this means for polar bears. He comes face-to-face with a tranquilised female, and discovers that mothers and cubs are going hungry as the sea ice on which they hunt disappears. In Canada, Inuit hunters have seen with their own eyes what scientists have seen from space; the Arctic Ocean has lost 30% of its summer ice cover over the last 30 years. For some, the melting sea ice will allow access to trillions of dollars worth of oil, gas and minerals. For the rest of us, it means the planet will get warmer, as sea ice is important to reflect back the sun's energy. Next David travels to see what's happening to the ice on land: in Greenland, we follow intrepid ice scientists as they study giant waterfalls of meltwater, which are accelerating iceberg calving events, and ultimately leading to a rise in global sea level. Temperatures have also risen in the Antarctic - David returns to glaciers photographed by the Shackleton expedition and reveals a dramatic retreat over the past century. It's not just the ice that is changing - ice-loving adelie penguins are disappearing, and more temperate gentoo penguins are moving in. Finally, we see the first ever images of the largest recent natural event on our planet - the break up of the Wilkins Ice Shelf, an ice sheet the size of Jamaica, which shattered into hundreds of icebergs in 2009.

In the boreal forests of Europe, a young brown bear clashes with wolves and tries to find a mate beneath the stars. On the edge of the Arctic Circle, lies an enchanted wilderness. In Europe's boreal forest, It's so far north that in winter, nights can last 20 hours. This woodland is home to a population of secretive bears that lives most of their lives in the dark. But now, using low-light cameras we can see their nighttime world as if it were day.

A bird's-eye view of some of the world's greatest natural spectacles. Amazing sights from five continents are revealed in a whole new light. Using cutting edge new filming techniques to show everything in exquisite detail, viewers have a uniquely privileged perspective. The first episode takes flight across North America, as a flock of millions of snow geese discover what it is like to be on the hit list of America's national bird: the bald eagle. In California, pelicans reveal devil rays that perform astonishing somersaults and find bizarre grunion fish that wriggle ashore to spawn. In Alaska, bald eagles swoop among brown bears fishing for salmon. And on the Great Plains, cowbirds duck and dive under the feet of fighting bison.

Earthflight departs on its grand European tour, using a host of techniques including taking extraordinary footage from microlites as they fly alongside imprinted birds. Among other wonders, cameras soar with cranes and geese over Venice, the white cliffs of Dover and Edinburgh. White storks leave Africa and struggle to reach Istanbul, the gateway to Europe, while cranes take an easier route over the monkey-guarded Rock of Gibraltar. In France, the white horses of the Camargue make a splash around the new arrivals. In Rome, the heat of the city lures 20 million starlings that perform nature's greatest aerial display to outwit peregrines. In Hungary, sand martins grab mayflies from the air; and at Bass Rock, gannets create Britain's greatest natural spectacle as they dive in exquisite slow-motion. The story takes an emotional turn as storks and swallows wait for their partners to return and indulge in a spot of DIY to impress. Finally, geese touch down in Svalbard to raise a family. To protect their young, a squadron of birds assemble to see off polar bears. With views of birds flying over the Loire Valley, London docklands and the bulb fieds of Holland, this is Europe as never before.