"This white wilderness, this emptiness, is the North Pole." "I'm standing in the middle of a frozen ocean." "Beneath my feet and for over 500 miles in every direction, there are several metres of ice." "But something significant is likely to happen here, at the North Pole, soon." "Chances are that some time, within the next few decades, perhaps even as soon as 2020, there will be open water here for the first time in human recorded history." "The Arctic and Antarctic are changing." "Enormous masses of ice that have been frozen for thousands of years are breaking apart and melting away." "Ice scientists are going to extremes to find out exactly what's going on." "For them, these are exciting times." "But the transformation that's being seen here will be felt far beyond the polar wilderness." "In this programme," "I'll be trying to understand what these changes mean, not just to the wildlife and people that live around the Poles, but for the whole planet." "I'm starting my journey in the Arctic, the far north of our planet." "It's still very cold outside by most people's standards, but the Arctic has been warming fast, twice as fast as the rest of our planet." "My first mission is to find out what effect that's having on the animals." "Although first, we have to find them." "It's April in Svalbard." "We are 1,000 miles north of the Arctic Circle, in search of the region's top predator." "We need to travel away from the land and out over the frozen sea." "There's some tracks right beneath us." "Over there." "I'm with a Norwegian team, which is giving the polar bears of Svalbard their yearly health check." "She's under us now." "I'll come round for a clean shot." "The team works together to give an anaesthetic injection from a dart gun without hurting the bear." "It takes tremendous skill." "Ah, you've got it." "I'll just back off until she's asleep." "Nobody likes to see a magnificent animal like a polar bear lolling about unconscious on the ice, but it's only by darting them in this way and keeping check on them year after year, that we can be sure we know" "what is happening to them and the population of polar bears as a whole." "Over the last 30 years, many teams have been seeing the condition of their local bears deteriorate." "Although not every bear is suffering." "How much?" "96, there." "And 102 here, so that's 197, yeah." "Is that good?" "It's not too bad, it's a bit above average." "So she's a bear in a good condition for Svalbard." "The trouble is that if this was underweight, she would be in trouble." "Not only from her own point of view, but from the point of her cubs, because an underweight female gives birth to underweight cubs and underweight cubs have a great problem of surviving their difficult first year in these circumstances." "It can be minus 40 degrees Centigrade when polar bear cubs emerge at the start of the Arctic spring, from their dens where they were born." "This mother hasn't eaten for half a year." "She and her cubs need to fatten up fast over the next few months and their chances of survival depend on what's happening beneath their feet." "These polar bears aren't walking on land." "They're roaming across the frozen surface of the sea." "And the bear's food lives under the ice." "Ringed seals are hunted by polar bears." "In fact, in some parts, polar bears eat almost nothing else." "So, it's very understandable that this mother ringed seal... who's looking at me now, should be a little apprehensive." "That pup of hers is only about three or four days old... and the pup won't be able to swim for another two or three days." "Seals have good reason to be nervous around their holes." "They need the holes to breathe when the sea is frozen, but this makes them easy to find." "Polar bears can sniff out seal holes, even if they're covered in snow." "Spring is the best hunting season." "This mother's found a food store under the snow that was probably made by an Arctic fox." "It's a time of plenty now, but the bear family need to make the best of it because the good times are about to come to an end." "As the weather warms, the ice beneath the bears' feet starts to break up and then melt." "And as the ice dwindles, so do the bears' chances of a successful hunt." "Most of the ice is lost over these shallow coastal waters, where most of the seals live." "It's now summer and these bears have a choice ... take their chances on the shrinking ice floes, or make for the safety of the land." "It's a case of sink or swim." "Bears have always gone hungry in the summer, but the length of time when there's enough ice for them to go hunting is getting shorter and shorter, across much of the Arctic." "This is hitting cubs particularly hard, because they can't survive for as long without feeding as their mother." "Cubs that were born underweight are at the greatest risk." "This mother and her cubs may well not get another meal until the sea freezes again in winter." "There's not much to eat on land and the fact is that the longer the cubs have to wait until the ice returns, the more likely they are to die." "Longer summers with no ice are probably the main reason why many polar bear populations are dropping." "To help monitor bears into the future, this female is being fitted with a radio collar to track her movements." "It's an extraordinary sensation to be so close to such a powerful animal." "With luck, carrying that collar, she will have more years to go yet... and be telling us a great deal about herself and the rest of the race of polar bears, as they face this very uncertain future." "The future of the ice cover on the sea isn't just an issue for the animals." "It's a big concern for the people who live in the Arctic and travel across the ice every day." "David Iqaqrialu is an Inuit from the village of Clyde River in the Canadian Far North." "There are very few roads up here, so David and his community, like most Inuit people, have always travelled across the frozen sea." "Dog sleds are the safest way to get around because the dogs feel thin ice underfoot and won't lead travellers into trouble." "Old-timers, like David, know the ice is as well as we know the streets in our local neighbourhood." "Every spring, cracks have always formed in the same places at the same time." "It's going to be big very soon." "After two weeks maybe... it will be more open." "But now, cracks are appearing where they never did before." "So, David and his friend, Laimikie, have taken on a new job." "They are using special GPS units to record the position of new cracks or weak ice." "These findings will be used by locals for their own safety, but they're also being studied by ice scientists, who want to predict how the ice will change in years to come." "THEY SPEAK THEIR NATIVE LANGUAGE" "The Inuit are keen to know what the future holds too because they've seen with their own eyes the changes that the scientists have seen from space." "This satellite photo from 1980 shows the Arctic Ocean at the end of the summer, when ice cover is at its minimum." "Since then, there's been a 30% drop in the area covered by ice." "But these images can't tell us about changes to the most important factor, the thickness of the ice." "Measuring thickness across the whole ocean was beyond scientists for many years, until help came from an unexpected source." "The Arctic Ocean is of huge military importance, as it's the shortest route between North America and Russia." "Since the late 1950s, British, US and Russian submarines have been patrolling the Arctic Ocean." "But as well as looking out for enemy activity, they've also been measuring the thickness of the ice, critical when looking for a place to surface." "When scientists got permission to look at the submarine crew's records, they discovered that the ice has been thinning fast." "In fact, it's nearly halved in thickness since 1980." "Across most of the Arctic Ocean, there are now just a couple of metres of ice." "It's so thin that it could melt away almost entirely in the summertime, and that includes the ice at the North Pole." "If current trends continue, then there will be open ocean here by summer's end, some time within the next few decades." "So, the days of the Arctic Ocean being covered by a continuous sheet of ice seem to have passed." "Whether or not that's a good or bad thing, of course, depends on your point of view." "Nobody has had a better view of the changes to the Arctic Ocean than the people of Barrow, the most northerly town in Alaska." "The people here have always survived by hunting on the frozen sea and they celebrate this at a festival every year." "The blanket toss was once the best way to spot distant animals to hunt, as lifelong resident Lewis Brower explains." "When we throw ourselves up into the blanket, you know, you get that much more of an 'Ahh' of seeing further and further out, so sometimes, you'll jump 15-20 feet in the air, and hopefully, you're being caught right back into the blanket." "I'm OK!" "THEY LAUGH" "But the old way of life is under threat." "When Lewis was young, the sea stayed frozen to the horizon until July, and some ice remained off-shore all summer." "But now, it's breaking up in June and melting away completely for two or three months." "I used to go out on the ice all the time at this time of the year, but we can't do that any more, cos there's no more ice." "Lewis can also see that the loss of sea ice is affecting the animals he hunts for a living." "Since 2007, something very strange has been happening on this stretch of coastline, close to Barrow." "Mother walruses, confused by the lack of ice, are crowding onto the land with their pups." "This very tight crowding isn't normal and it's caused many youngsters to be crushed to death." "Many Arctic animals are threatened by the changing conditions and that's also bad news for the traditional hunters." "But the ice loss could be good news for some people." "There are trillions of dollars' worth of oil and gas under the Arctic Ocean." "But the only way to get to them, until now, has been by building expensive artificial islands, like this." "But if the sea ice goes, it will be much easier to drill for the huge riches below." "So, the countries that surround the Arctic are scrambling to stake their claims." "This daring attempt by the Russians to claim the disputed seabed at the North Pole in 2007 caused fury among the competing countries and it's unlikely to be the last such dispute." "The Arctic has never been so important and not just because of its resources." "The North-West passage, a legendary sea route around the north of Canada and Alaska, cleared of ice in the summer of 2007 for the first time since records began." "This promises a much faster and cheaper shipping route between the Atlantic and Pacific Oceans." "And some wildlife could benefit from an ice-free Arctic too." "Bowhead whales are one of just a few whales that can live year-round in the Arctic because they have no dorsal fin." "This means they can come up for air in small spaces and travel easily under the ice." "Their unique body shape used to mean that the Arctic whales had the seas to themselves for most of the year." "But now, some cousins from down south are moving in." "Killer whales are now a much more common sight in the Arctic." "Their tall fins make it difficult for them to travel under ice, but the longer summers mean they can travel much further north and make the most of the rich Arctic seas." "For animals and people, it will be those that can adapt who will thrive in a changing Arctic." "But the loss of sea ice isn't just an issue for the Arctic, because the state of the ice affects the climate of the whole planet." "Because it's white, the ice reflects up to 90% of the Sun's energy." "This is called the albedo effect and it's why we often see heat haze in the Arctic, even when the air feels cold." "The frozen Arctic Ocean acts as a huge reflector, bouncing back the Sun's heat into space." "Throughout history, that has helped to cool the planet, but when the ice melts, it's a different story." "Because sea water is dark, it absorbs most of the Sun's heat." "In the Arctic, this can trigger a chain reaction, as the warming water melts more ice, exposing more water to the Sun's heat." "This cycle of warming, as huge areas start to absorb rather than reflect heat, is the main reason why the Arctic, a region the size of North America, is warming twice as fast as the rest of the Earth." "So, melting sea ice is a big issue." "But there's another kind of ice that could have an even more dramatic impact on our world." "The ice that is found on land." "This is fresh water ice, formed from thousands of years of accumulated snowfall." "This is the front of a glacier, quite a small one, believe it or not." "Glaciers are like rivers of frozen fresh water flowing across the surface of the land." "This one, like most polar glaciers, is flowing down from a vast inland ice sheet." "And it's what happens to those ice sheets that could radically alter the face of the planet." "The Greenland ice sheet is by far the largest in the Arctic." "It's two miles thick in places and six times the size of the United Kingdom." "Every summer, some of the surface of the ice sheet melts, forming sapphire blue lakes of melt water." "More and more of these lakes have been forming as Greenland has warmed over the last 20 years." "This lake has grown over several weeks and now it's overflowing, carving a deep channel through the ice." "A network of channels criss-crosses the ice sheet, but many of them come to an abrupt end." "Huge holes, like this, can open up quite suddenly, draining the melt water away." "Alun Hubbard is a glaciologist, studying the enormous power of these waterfalls, which are known as moulins." "Alun is here to study where the melt water goes and what effect it has on the remaining ice." "To do that, he needs to find a moulin that has recently run dry." "Just a week ago, there was a three-mile long, ten-metre deep lake here." "The weight of all that water cracked the ice beneath and the late drained in just a few hours with incredible force." "Thousand-tonne ice boulders were tossed about like dice." "Alun's team have found the hole down which the lake disappeared and they want to have a closer look." "It's not a job for anyone with a fear of heights." "Alun wants to place a sensor deep into the moulin to discover how much water is flowing through the ice." "As they drop, they travel back in time." "30 metres down and they reach ice formed from snow that fell 10,000 years ago, in the last Ice Age." "When this lake drained and the plug got pulled and the whole lot flushed down through here, this ice sheet, it rose by a metre as that water accessed the bed and forced, jacked up the ice sheet." "So, we know that the water in this whole plumbing cavity system, down here, we know that shoots straight through that ice and actually hits the bed of the ice sheet." "We've hit the water, I can see the water now." "Great." "Nice work." "This daring experiment is measuring how the water flowing under the ice sheet affects the speed with which the glaciers flow from it, down to the sea." "The theory is that the water is acting as a lubricant." "So, the more water there is, the faster the glacier flows." "To the naked eye, glaciers don't appear to move at all." "But move, they do." "These unique time-lapse images were captured over the last four years." "Through long observations, we now know that Greenland's ice is flowing down to the sea twice as quickly as it was 20 years ago." "The speed of the glaciers affects our sea levels because when they reach the water, they break apart into icebergs." "Occasionally, a real mega-berg is born." "This is the Store Glacier in May 2010." "75 million tonnes of ice, that had been sitting on land for thousands of years, has broken away." "Events like this have become increasingly common, as Greenland's glaciers flow faster into the sea." "Every single one of these icebergs raises the sea level a small amount." "Scientists monitoring the ice sheet predict that Greenland might add as much as a half metre to world sea levels by the end of the century, enough to swamp many of the world's low-lying islands." "99% of the Arctic's fresh water ice is in Greenland." "It's a staggeringly big ice sheet, but it's just a drop in the ocean compared to that at the southern end of our planet." "In Antarctica, there is ten times more ice, by far the largest concentration of ice on Earth." "Our exploration of the Antarctic only began a little over 100 years ago." "The study of ice retreat here was unwittingly begun on an expedition led by the great early explorer Ernest Shackleton." "In 1916, after their expedition boat was crushed and sunk by ice," "Shackleton and two companions set off to summon help in a tiny boat." "They sailed over 800 miles across the Southern Ocean to the island of South Georgia, on the edge of the Antarctic." "Near starving and dressed in rags, the three men walked across the ice sheet at the centre of the island, knowing there was a whaling base on the opposite coast where they could summon help." "This team of Royal Marines is re-tracing the steps of that journey in tribute to Shackleton and his men." "But for all their efforts, they can't exactly copy the great walk because the ice is not as it was." "A number of South Georgia's glaciers were photographed by Shackleton's cameraman." "Frozen Planet saw a dramatic change when they returned 94 years later." "Most of South Georgia's glaciers have shrunk since Shackleton's time and most of that has happened since I first went to the Antarctic 30 years ago." "I've been to South Georgia several times and seen how greatly the glaciers there have changed." "This photograph of a glacier reaching right down to the sea was taken just six years before I first visited in 1981." "Now, that glacier has retreated by 400 metres away from the beach." "Temperatures in South Georgia have risen sharply, but the Southern" "Hemisphere's most dramatic warming has happened a little further south." "In recent years, stronger winds blowing over the Southern Ocean have brought warmer air to the 800 mile-long finger of land that forms the northern extremity of the Antarctic continent." "Here, on the Antarctic Peninsula, the changing wind patterns have driven temperatures up by nearly three degrees Centigrade over the last 50 years." "Ten times the average rate of the rest of the planet." "The rapid warming is having a big effect on the birdlife." "The Adelie penguin is the most southerly nesting of all penguins." "And, like the polar bear, up in the north, their lives are dependent on the sea ice." "Adelies spend their whole lives near ice." "These birds have spent the winter feeding at the ice edge, but now it's spring and they've started a long trek over the frozen sea towards land." "They're heading for areas of exposed rock, where they gather to breed, in colonies that can be over 100,000 strong." "But it seems that Adelies don't find the conditions on the Peninsula to their liking any more." "17 years ago, when I was last in the Antarctic, there were large colonies of Adelie penguins all along the Antarctic Peninsula." "Now, warming temperatures have meant less sea ice and Adelie penguin numbers are in decline." "Many colonies have been emptying fast." "It may be that penguins are starving, or it may be that they're heading south to colder climes where there's still plenty of ice on the sea." "But, as in the Arctic, while ice-loving animals are feeling the heat, animals that like it a bit more cosy are moving in." "The bright orange beaks of Gentoo penguins are a much more common sight on the Peninsula these days." "I always used to know them as residents of the slightly warmer islands north of the Antarctic." "But they've moved south in numbers." "There are thought to be ten times more Gentoos on the Peninsula now than just 30 years ago." "The peninsula has warmed a great deal, but the same is not true further south." "The Antarctic continent is smothered by the world's greatest ice sheet." "One and half times the size of Australia and up to three miles thick." "A staggering 75% of the Earth's fresh water is locked up in this ice." "Global sea levels would rise by some 60 metres if all this was to melt." "But what chance is there of that happening here in the coldest, most hostile place on Earth?" "The ice beneath me, up here on top of the ice cap, is so thick that I am short of breath, simply because of the altitude." "This is midsummer and the average temperature is some 20 degrees below freezing." "And I can tell you it feels much lower than that." "And even the worst predictions don't suggest that the air is going to warm enough to melt the ice." "But now, scientists are asking a different question." "Could the speed at which the Antarctic ice flows off the land be increased by a warmer ocean?" "Where the ice sheet meets the sea, scientists are going to extreme lengths to find out." "Firing." "Andy Smith works for the British Antarctic Survey." "What we have here is one kilogramme of pentolite explosive." "We're going to use this to generate a shockwave and record the echoes that come back from underneath the ice." "Firing." "Andy is particularly interested in mapping the underside of the ice around the coast." "Because here, it isn't resting on land." "It's floating on sea water, so if sea temperatures rise just a little, it can be melted from below." "Around the coast of Antarctica, the glaciers have flowed out across the sea to form immense masses of floating fresh water ice, called ice shelves." "These freeze to the land around them, sticking fast and acting like bathplugs, holding back the flow of the glaciers into the sea." "On the Antarctic Peninsula, a one-degree sea temperature rise has helped to break apart seven major ice shelves in the last 30 years." "This is the Larsen B ice shelf, three times the size of Greater London, breaking apart in 2002." "Afterwards, the glaciers it had been holding back started flowing up to six times faster." "In 2008, a much larger ice shelf at the southern end of the peninsula started to break up." "It's an enormous event that's never been filmed before." "Andy Smith is flying down the Peninsula to study this phenomenon first hand." "As Andy's team reaches their destination, the scale of what's been happening soon becomes clear." "Here, for thousands of years, an area the size of Yorkshire has been covered by a sheet of ice 200 metres thick." "But now, over half of that has broken apart." "Andy has been studying Antarctic ice for 25 years, but even he is blown away by what he's seeing." "Now, that is pretty awesome." "That is remarkable." "The edge of the ice shelf has just, kind of, disintegrated." "Some of the big pieces look like they could be a mile or more in size." "It's almost like a, sort of, a slow motion explosion." "It all pushes outwards very quickly." "Every one of these huge icebergs will slowly drift out to sea." "To study how fast that happens, Andy needs to get closer to the action." "Landing on an iceberg is another first for Andy's team." "This satellite transmitter will help to track the continued break-up of this colossal ice shelf." "The remainder of the Wilkins looks set to break apart soon." "It's the latest ice shelf to disintegrate in a wave that's been travelling southwards, playing a major role in the loss of ice from the Peninsula." "Next in line, and already weakening in places, are the ice shelves that hold back Antarctica's gigantic continental ice sheet." "And it would only take a small corner of this to slide into the sea to have major global consequences." "We've only started to see changes in the Arctic and Antarctic recently." "So, it's hard to predict exactly what impact these changes will have." "But we can see for ourselves that these places are changing and on a scale that is hard to ignore." "The Poles, North and South, may seem very remote, but what is happening here is likely to have a greater effect upon us than any other aspect of global warming." "If the Arctic sea ice continues to disappear, it will drive up the planet's temperature more quickly." "And the melting ice sheets could contribute to a sea level rise of a metre, enough to threaten the homes of millions of people around the world's coasts by the end of the century." "We've seen that the animals are already adapting to these changes, but can WE respond to what is happening now to the frozen planet?"