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[David Attenborough] <i>Just 50 years ago,</i>

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<i>we finally ventured to the moon.</i>

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<i>For the very first time,</i>
<i>we looked back at our own planet.</i>

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<i>Since then, the human population</i>
<i>has more than doubled.</i>

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<i>This series will celebrate</i>
<i>the natural wonders that remain,</i>

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<i>and reveal what we must preserve</i>

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<i>to ensure people and nature thrive.</i>

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<i>The polar regions of our planet</i>
<i>may seem beyond the reach of most of us,</i>

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<i>but they are not beyond our influence.</i>

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<i>We, unintentionally,</i>
<i>are changing these frozen worlds,</i>

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<i>and these changes</i>
<i>will not just affect the poles</i>

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<i>but the whole planet.</i>

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<i>Antarctica.</i>

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<i>The southern end of our planet,</i>
<i>and the coldest place on Earth.</i>

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<i>It has been frozen for 30 million years.</i>

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<i>In its center, the covering of ice</i>
<i>is over four kilometers thick.</i>

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<i>Entire mountain ranges</i>
<i>are buried beneath it.</i>

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<i>Here, it is so cold that each winter</i>

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<i>19 million square kilometers of ocean</i>
<i>freezes,</i>

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<i>more than doubling</i>
<i>the size of the ice cap.</i>

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<i>But when, in spring, the sea ice melts,</i>

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<i>life returns once again</i>
<i>to the continent's shores.</i>

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<i>The peninsula that stretches north</i>
<i>towards South America</i>

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<i>is the first part of it</i>
<i>to be released from winter's grip.</i>

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<i>As the sea ice breaks up,</i>

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<i>life returns.</i>

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[gulls cawing]

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There is a <i>greater variety</i>
<i>of living creatures here</i>

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<i>than anywhere else in Antarctica.</i>

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<i>Gentoo penguins</i>
<i>spend most of their lives at sea,</i>

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<i>but now, in spring,</i>
<i>they have to come ashore to breed.</i>

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<i>They're the fastest of all penguins</i>
<i>in water,</i>

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<i>but on land,</i>
<i>life takes on a slower pace.</i>

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<i>It's an uphill struggle</i>
<i>to reach their nesting grounds...</i>

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[penguins honking]

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<i>...but penguins never give up.</i>

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<i>The paths they follow,</i>
<i>carved by thousands of tiny footsteps,</i>

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<i>lead to Antarctica's rarest commodity.</i>

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<i>Bare rock.</i>

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<i>Less than one percent of Antarctica</i>
<i>is ice-free,</i>

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<i>and these rocky patches</i>

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<i>are the only places</i>
<i>where gentoos can lay their eggs.</i>

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<i>It's been a 30-minute struggle,</i>

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<i>but he's almost at the top,</i>
<i>where his mate is waiting for him.</i>

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[honking]

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<i>He presents her with a stone,</i>

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<i>a gift to improve the nest</i>
<i>and so win her favor.</i>

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[both honking]

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<i>He's back just in time.</i>

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<i>There's another mouth to feed.</i>

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[chirrups]

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<i>Gentoo penguins used to be rare</i>
<i>in this part of Antarctica,</i>

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<i>but now, as temperatures rise,</i>
<i>their numbers here are increasing.</i>

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<i>Sea ice may appear to be flat</i>
<i>and lifeless,</i>

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<i>but beneath it there is another world.</i>

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<i>As the ice melts,</i>
<i>the light filters through,</i>

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<i>and algae, that have been trapped</i>
<i>within the ice all winter, flourish.</i>

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<i>This upside-down world</i>

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<i>is the polar equivalent</i>
<i>of the great grasslands.</i>

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<i>The ice is the soil</i>
<i>upon which plant life grows,</i>

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<i>and the herds of grazers soon arrive.</i>

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<i>Antarctic krill.</i>

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<i>Trillions of them swarm</i>
<i>in the waters around Antarctica.</i>

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<i>Protected by the ice above,</i>
<i>they graze on algae whilst the sun shines.</i>

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<i>But the good times don't last long.</i>

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<i>Once all the ice has melted,</i>
<i>the krill lose their protection,</i>

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<i>and predators appear.</i>

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<i>Penguins may have lost</i>
<i>their ability to fly,</i>

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<i>but they still form flocks,</i>
<i>as so many birds do.</i>

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<i>The longer they dive,</i>

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<i>the longer it takes them</i>
<i>to catch their breath.</i>

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<i>Ruffling their feathers traps air,</i>
<i>which makes their bodies more streamlined.</i>

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<i>One last breath...</i>

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<i>and the whole group dives down together.</i>

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<i>The gentoos follow the krill</i>
<i>down to depths of over 200 meters.</i>

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<i>What a flock can catch in one dive,</i>

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<i>a giant traps in a single mouthful.</i>

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<i>Humpback whales from the tropics</i>

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<i>have traveled</i>
<i>over 8,000 kilometers to get here.</i>

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<i>This one chooses to feed alone.</i>

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<i>This technique, part lunge, part pounce,</i>

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<i>only works when the krill</i>
<i>are close to the surface.</i>

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<i>As more humpbacks arrive,</i>
<i>they begin to work in teams.</i>

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<i>By lunging together,</i>

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<i>the overspill from one huge mouth</i>
<i>is not lost but collected by another.</i>

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<i>Some humpbacks regularly work</i>
<i>in an even more coordinated way.</i>

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<i>They do so</i>
<i>when krill has descended to some depth.</i>

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<i>Once in position,</i>
<i>they blast air from their blowholes.</i>

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<i>Working together,</i>

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<i>they create a curtain of bubbles</i>
<i>around their prey.</i>

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<i>As the spiraling net tightens,</i>
<i>the krill are driven closer together,</i>

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<i>and then the whales lunge upwards</i>
<i>and collect them.</i>

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<i>Almost all humpback whales</i>
<i>in the southern hemisphere</i>

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<i>come to the Antarctic to feed on krill.</i>

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<i>Since the ban on commercial whaling,</i>
<i>their numbers have recovered dramatically,</i>

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<i>but their food supply is now under threat.</i>

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<i>In the last 50 years,</i>

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<i>with warming temperatures</i>
<i>and disappearing sea ice,</i>

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<i>krill stocks</i>
<i>in this part of the Southern Ocean</i>

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<i>have more than halved.</i>

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<i>Other sea hunters come here</i>
<i>seeking bigger prey than krill.</i>

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<i>Antarctica's top predators.</i>

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<i>Orca, killer whales.</i>

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<i>Over half of the world's orca</i>
<i>patrol these polar seas.</i>

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<i>This particular pod</i>
<i>specializes in hunting penguins.</i>

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<i>They shift into stealth mode.</i>

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<i>Hunting without making a sound,</i>
<i>so that their prey won't hear them coming.</i>

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<i>A penguin can outmaneuver</i>
<i>a single killer whale,</i>

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<i>but it can seldom escape a pod.</i>

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<i>This hunt may seem cruel,</i>

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<i>but important life skills</i>
<i>are being passed down the generations.</i>

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<i>From killer whales to krill,</i>

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<i>all life here ultimately depends</i>
<i>upon Antarctica's sea ice.</i>

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<i>The seas that surround Antarctica</i>
<i>are the roughest on our planet.</i>

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<i>These churning waters</i>
<i>draw up nutrients from the deep</i>

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<i>and create vast, rich fishing grounds</i>
<i>for nomads like the wandering albatross.</i>

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<i>Beneath the waves,</i>
<i>currents are flowing away from Antarctica,</i>

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<i>transporting nutrients across the planet,</i>
<i>fertilizing the oceans</i>

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<i>and helping to regulate</i>
<i>global temperatures.</i>

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<i>The island of South Georgia.</i>

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<i>It's far enough north</i>

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<i>to be beyond the reach of the sea ice</i>
<i>even in midwinter,</i>

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<i>and many animals live here</i>
<i>the year round.</i>

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<i>This wandering albatross chick</i>
<i>has been sitting on its nest all winter,</i>

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<i>and is entirely dependent</i>
<i>on its parents returning with food.</i>

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<i>It may have to wait a few days</i>
<i>between meals, or even a couple of weeks,</i>

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<i>but at least</i>
<i>it's not the only one who's waiting.</i>

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<i>Albatross chicks need to spend</i>
<i>a whole year growing</i>

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<i>before they're ready</i>
<i>to take their first flight.</i>

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<i>And then they spend several years at sea</i>
<i>before they return to land.</i>

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[honking]

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<i>Coming in to land</i>
<i>on three-meter wings takes some practice.</i>

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<i>Albatross don't have reverse thrusters.</i>

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[chirping]

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<i>The chick</i>
<i>is this female's first.</i>

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<i>She's been raising it for six months,</i>
<i>and has another six to go.</i>

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<i>Her chick is smaller than it should be,</i>

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<i>a sign that her mate</i>
<i>has not been returning with food.</i>

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<i>He may well have been</i>
<i>one of the many that die,</i>

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<i>entangled on longline fishing lines.</i>

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<i>South Georgia is an ideal place</i>
<i>for wanderers to raise their young,</i>

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<i>but now fewer adults</i>
<i>are returning here to nest,</i>

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<i>and in recent years,</i>

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<i>the breeding population</i>
<i>has declined by 40 percent.</i>

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<i>For now, waiting on its nest,</i>
<i>the chick is safe.</i>

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<i>There are no land predators here.</i>

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<i>But the same cannot be said</i>
<i>for South Georgia's seas.</i>

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<i>Giant kelp flourishes</i>
<i>in these ice-free waters.</i>

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<i>The perfect place for an ambush.</i>

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<i>Leopard seals overwinter here</i>
<i>to escape Antarctica's frozen ocean.</i>

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<i>They should have returned south by now,</i>

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00:23:30,410 --> 00:23:32,579
<i>but this year they've stayed longer.</i>

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00:23:39,043 --> 00:23:42,172
<i>And they've delayed their departure</i>
<i>for good reason.</i>

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<i>There are king penguins here.</i>

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<i>Each is a substantial meal,</i>

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00:24:01,858 --> 00:24:02,859
<i>if you can catch it.</i>

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00:24:11,201 --> 00:24:12,785
<i>Returning to feed their chicks,</i>

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00:24:13,036 --> 00:24:16,247
<i>the kings have no choice</i>
<i>but to run the gauntlet.</i>

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00:24:24,297 --> 00:24:26,466
<i>Kings rarely porpoise like this.</i>

160
00:24:28,593 --> 00:24:32,847
<i>It uses more energy,</i>
<i>but it's faster than traveling underwater.</i>

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00:25:15,265 --> 00:25:19,185
<i>It's hard to select a moving target</i>
<i>in a panicking crowd,</i>

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00:25:25,441 --> 00:25:28,486
<i>but if there are stragglers,</i>
<i>the odds change.</i>

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<i>Razor-sharp teeth versus a stabbing beak.</i>

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00:26:12,655 --> 00:26:13,698
<i>It's stalemate.</i>

165
00:26:15,033 --> 00:26:17,702
<i>Both are exhausted after the chase.</i>

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00:26:27,795 --> 00:26:31,633
<i>The hunter decides that the meal</i>
<i>is not worth the fight.</i>

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00:26:34,135 --> 00:26:35,511
[cawing]

168
00:26:41,768 --> 00:26:44,604
<i>For the penguin,</i>
<i>it was too close for comfort,</i>

169
00:26:44,896 --> 00:26:49,400
<i>but that was just the first hurdle</i>
<i>in getting back to feed its chick.</i>

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[cawing]

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<i>It isn't going to be</i>
<i>a walk in the park.</i>

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[elephant seals snoring]

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00:27:25,645 --> 00:27:28,815
<i>Luckily,  penguin is not on their menu.</i>

174
00:27:35,363 --> 00:27:38,825
<i>Still, it's best</i>
<i>to let sleeping giants lie.</i>

175
00:27:45,456 --> 00:27:46,541
[penguin honks]

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00:27:52,463 --> 00:27:55,800
<i>Elephant seal females</i>
<i>don't take kindly</i>

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00:27:55,883 --> 00:27:57,844
<i>to being disturbed from their slumber,</i>

178
00:27:59,429 --> 00:28:03,349
<i>but it's the four-tonne males</i>
<i>you need to look out for.</i>

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00:28:03,891 --> 00:28:05,893
[rasping grunting]

180
00:28:14,193 --> 00:28:17,363
<i>They are fighting</i>
<i>for access to the females.</i>

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00:28:25,496 --> 00:28:30,752
<i>Getting bulldozed under angry blubber</i>
<i>is to be avoided at all costs.</i>

182
00:28:41,721 --> 00:28:42,555
<i>An escape route.</i>

183
00:28:48,102 --> 00:28:49,187
<i>Time to run for it.</i>

184
00:29:01,616 --> 00:29:04,035
<i>At last, he's reached the nursery.</i>
<i>Now comes his final challenge.</i>

185
00:29:11,167 --> 00:29:14,879
<i>Finding his chick</i>
<i>in the crowd of half a million.</i>

186
00:29:19,258 --> 00:29:20,426
<i>He calls...</i>

187
00:29:21,052 --> 00:29:22,804
[cawing]

188
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<i>...and listens</i>
<i>for  a recognizable reply.</i>

189
00:29:32,855 --> 00:29:34,857
[chirping]

190
00:29:41,697 --> 00:29:44,408
<i>His chick could be</i>
<i>another mile or two away,</i>

191
00:29:45,076 --> 00:29:46,410
<i>at the back of the colony.</i>

192
00:29:50,873 --> 00:29:52,667
<i>But that's the trouble with chicks.</i>

193
00:29:53,251 --> 00:29:54,961
<i>They're never where you left them.</i>

194
00:29:57,338 --> 00:29:59,590
<i>Astonishingly, in all this racket,</i>

195
00:29:59,715 --> 00:30:03,594
<i>a parent and its chick</i>
<i>can recognize each other's calls.</i>

196
00:30:04,011 --> 00:30:05,555
[chirping]

197
00:30:13,646 --> 00:30:17,108
<i>The things parents go through</i>
<i>to deliver a meal.</i>

198
00:30:20,403 --> 00:30:21,737
<i>If only they knew.</i>

199
00:30:29,328 --> 00:30:31,122
<i>For such a small island,</i>

200
00:30:31,289 --> 00:30:35,209
<i>South Georgia supports</i>
<i>an extraordinary quantity of life.</i>

201
00:30:40,047 --> 00:30:43,217
<i>All these creatures</i>
<i>ultimately depend on the krill</i>

202
00:30:43,551 --> 00:30:46,888
<i>that develops under the sea ice</i>
<i>around the Antarctic peninsula.</i>

203
00:30:49,932 --> 00:30:51,434
<i>With sea ice disappearing,</i>

204
00:30:51,934 --> 00:30:55,187
<i>so South Georgia's future</i>
<i>is far from certain.</i>

205
00:31:11,245 --> 00:31:13,748
<i>At the other end of the planet,</i>
<i>in the north,</i>

206
00:31:14,457 --> 00:31:18,920
<i>the effects of climate change</i>
<i>are being felt even more intensely.</i>

207
00:31:21,088 --> 00:31:24,133
<i>The Arctic is not a continent</i>
<i>surrounded by sea</i>

208
00:31:25,468 --> 00:31:28,304
<i>but a frozen ocean ringed by land.</i>

209
00:31:32,350 --> 00:31:37,271
<i>Here, in spring, the sea ice</i>
<i>is still at its maximum extent.</i>

210
00:31:42,777 --> 00:31:48,991
<i>It's a vast, firm hunting ground</i>
<i>for the planet's largest land carnivore.</i>

211
00:32:00,711 --> 00:32:04,131
<i>A male polar bear</i>
<i>in search of his next meal</i>

212
00:32:04,548 --> 00:32:08,594
<i>on the frozen fjords of Svalbard</i>
<i>in the high Arctic.</i>

213
00:32:13,182 --> 00:32:16,936
<i>He's looking for seals,</i>
<i>which make up the bulk of his diet.</i>

214
00:32:24,568 --> 00:32:28,531
<i>He must eat two-thirds</i>
<i>of the food he needs for the whole year</i>

215
00:32:28,823 --> 00:32:33,160
<i>before the ice melts</i>
<i>and his hunting platform disappears.</i>

216
00:33:06,777 --> 00:33:11,782
<i>The ringed seal mother had no choice</i>
<i>but to leave her pup alone on the surface.</i>

217
00:33:22,460 --> 00:33:26,922
<i>In the past, she would have built a den</i>
<i>inside a ridge on the ice,</i>

218
00:33:28,632 --> 00:33:32,470
<i>but now the sea freezes so late</i>
<i>that the ice is flat,</i>

219
00:33:32,970 --> 00:33:36,432
<i>and she had to leave her pup</i>
<i>out in the open.</i>

220
00:33:47,401 --> 00:33:51,280
<i>These changes in the ice</i>
<i>may benefit the bears for now,</i>

221
00:33:51,822 --> 00:33:53,491
<i>but in the long term,</i>

222
00:33:53,574 --> 00:33:56,952
<i>a crash in their most important prey</i>
<i>will follow.</i>

223
00:34:01,082 --> 00:34:05,669
<i>This new, flatter ice</i>
<i>makes life difficult for the bears, too.</i>

224
00:34:06,545 --> 00:34:10,466
<i>There's nowhere for them to hide</i>
<i>in order to creep up on a seal.</i>

225
00:34:15,179 --> 00:34:20,184
<i>And for a mother with a young cub in tow,</i>
<i>being stealthy isn't easy.</i>

226
00:34:36,367 --> 00:34:39,578
<i>The cub doesn't yet appreciate</i>
<i>the need for care</i>

227
00:34:41,330 --> 00:34:43,249
<i>when sneaking up on a seal.</i>

228
00:34:45,960 --> 00:34:48,170
<i>With fewer seals hiding in dens,</i>

229
00:34:48,379 --> 00:34:51,799
<i>learning this pounding technique,</i>
<i>once so useful,</i>

230
00:34:52,883 --> 00:34:54,468
<i>is now almost pointless.</i>

231
00:35:06,272 --> 00:35:10,901
<i>Still, at least he's discovered</i>
<i>what a seal hole looks like..</i>

232
00:35:22,413 --> 00:35:26,959
<i>His mother knows that overcast conditions</i>
<i>are good for hunting,</i>

233
00:35:28,586 --> 00:35:30,880
<i>and he knows when she's serious.</i>

234
00:35:39,346 --> 00:35:42,266
<i>Adult seals make a much better meal.</i>

235
00:35:54,069 --> 00:35:57,281
<i>Her cub carefully treads in her footsteps,</i>

236
00:35:59,617 --> 00:36:02,328
<i>and takes care not to break her outline.</i>

237
00:36:06,665 --> 00:36:08,834
<i>Neither must put a foot wrong.</i>

238
00:36:15,799 --> 00:36:18,219
<i>They must move as one.</i>

239
00:36:44,620 --> 00:36:47,581
<i>Most seal hunts end in failure.</i>

240
00:36:55,214 --> 00:36:57,258
<i>The bears must keep searching.</i>

241
00:37:01,387 --> 00:37:03,597
<i>Her cub wanders off,</i>

242
00:37:06,225 --> 00:37:07,893
<i>and gets another chance.</i>

243
00:37:18,654 --> 00:37:21,490
<i>A seal pup alone on the ice.</i>

244
00:37:26,370 --> 00:37:29,373
[seal pup whimpering]

245
00:37:32,209 --> 00:37:36,797
<i>Now it's not stealth</i>
<i>that is needed, but confidence.</i>

246
00:37:41,885 --> 00:37:43,929
<i>There's nothing the mother can do,</i>

247
00:37:46,515 --> 00:37:50,602
<i>except hope that the pup makes it</i>
<i>back to her hole in time.</i>

248
00:37:51,854 --> 00:37:52,688
[whimpers]

249
00:37:58,193 --> 00:38:01,030
<i>The inexperienced young hunter</i>
<i>hesitates.</i>

250
00:38:11,373 --> 00:38:12,916
<i>Its mother knows better.</i>

251
00:38:36,982 --> 00:38:38,984
<i>Safe under the ice.</i>

252
00:38:44,990 --> 00:38:50,579
<i>Polar bears are adaptable predators,</i>
<i>but they rely on sea ice.</i>

253
00:38:52,498 --> 00:38:56,168
<i>If that disappears, so will the bears.</i>

254
00:39:10,265 --> 00:39:13,811
<i>Summer at the ice edge</i>
<i>in the Canadian Arctic,</i>

255
00:39:14,395 --> 00:39:18,232
<i>and the annual retreat of sea ice</i>
<i>is well underway.</i>

256
00:39:27,825 --> 00:39:30,744
<i>As it melts, nomads arrive.</i>

257
00:39:50,347 --> 00:39:54,476
<i>Narwhal, the origin of the unicorn legend.</i>

258
00:39:55,310 --> 00:40:01,233
<i>Their three-meter tusk is, in fact,</i>
<i>no more than an overgrown canine tooth,</i>

259
00:40:02,192 --> 00:40:06,405
<i>but its exact function,</i>
<i>like so much about narwhals,</i>

260
00:40:06,738 --> 00:40:08,991
<i>is still, in part, a mystery.</i>

261
00:40:14,705 --> 00:40:18,417
<i>Each summer, narwhals travel</i>
<i>to the same part of the Arctic,</i>

262
00:40:18,792 --> 00:40:23,172
<i>and patiently wait at the ice edge</i>
<i>for a crack to open up.</i>

263
00:40:26,216 --> 00:40:30,179
<i>A lead in the ice,</i>
<i>wide enough for them to swim along.</i>

264
00:40:43,484 --> 00:40:45,611
<i>Eventually, a crack appears.</i>

265
00:40:47,946 --> 00:40:50,949
<i>Their passage to sheltered, shallow bays.</i>

266
00:41:12,304 --> 00:41:16,892
<i>Narwhals are extremely timid</i>
<i>and rarely filmed underwater.</i>

267
00:41:44,878 --> 00:41:49,383
<i>These ice whales eagerly travel</i>
<i>down the leads as soon as they open</i>

268
00:41:49,591 --> 00:41:52,761
<i>because they're safer from predators</i>
<i>protected by the ice.</i>

269
00:42:01,603 --> 00:42:05,482
<i>The leads may also give them access</i>
<i>to new feeding grounds.</i>

270
00:42:18,829 --> 00:42:20,622
<i>Sea ice is not just crucial</i>

271
00:42:20,706 --> 00:42:23,750
<i>to the lives of those creatures</i>
<i>that live around the poles.</i>

272
00:42:25,752 --> 00:42:30,424
<i>It plays a vital role in determining</i>
<i>the climate of the whole planet.</i>

273
00:42:33,594 --> 00:42:36,179
<i>A white surface keeps the earth cool</i>

274
00:42:36,430 --> 00:42:40,350
<i>by reflecting most of the sun's energy</i>
<i>back into space.</i>

275
00:42:50,736 --> 00:42:52,946
<i>A dark surface does the opposite,</i>

276
00:42:53,947 --> 00:42:56,867
<i>absorbing over 90 percent</i>
<i>of the sun's energy</i>

277
00:42:57,242 --> 00:42:58,869
<i>and so warming the earth.</i>

278
00:43:03,415 --> 00:43:04,750
<i>As the sea ice shrinks,</i>

279
00:43:05,042 --> 00:43:09,838
<i>we're starting to lose one of our planet's</i>
<i>protective white shields.</i>

280
00:43:14,009 --> 00:43:15,427
<i>For thousands of years,</i>

281
00:43:15,636 --> 00:43:19,473
<i>there's been a balance</i>
<i>in the advance and retreat of the sea ice,</i>

282
00:43:20,223 --> 00:43:21,850
<i>but that is no longer the case.</i>

283
00:43:22,601 --> 00:43:24,728
<i>Today, during the summer months,</i>

284
00:43:24,978 --> 00:43:30,108
<i>there is 40 percent less sea ice cover</i>
<i>than there was in 1980.</i>

285
00:43:39,576 --> 00:43:44,331
<i>The Arctic is warming twice as fast</i>
<i>as anywhere else on our planet.</i>

286
00:43:45,290 --> 00:43:50,253
<i>By 2040, the ocean here</i>
<i>will be largely free of ice</i>

287
00:43:50,462 --> 00:43:51,797
<i>during the summer months.</i>

288
00:44:09,272 --> 00:44:14,236
<i>This loss of ice will inevitably</i>
<i>have devastating consequences</i>

289
00:44:14,569 --> 00:44:16,780
<i>for all those that still depend on it.</i>
[birds cawing]

290
00:44:30,210 --> 00:44:33,547
<i>The far northeastern coast</i>
<i>of Russia.</i>

291
00:44:36,383 --> 00:44:38,385
[grunting]

292
00:44:50,480 --> 00:44:55,694
<i>This is the largest gathering</i>
<i>of walrus on the planet.</i>

293
00:45:06,955 --> 00:45:12,294
<i>Over a hundred thousand have hauled out</i>
<i>on one single beach.</i>

294
00:45:19,968 --> 00:45:23,889
<i>They do so out of desperation,</i>
<i>not out of choice.</i>

295
00:45:27,809 --> 00:45:31,229
<i>Their natural home is out on the sea ice.</i>

296
00:45:38,195 --> 00:45:41,114
<i>But the ice has retreated</i>
<i>away to the north,</i>

297
00:45:42,783 --> 00:45:46,411
<i>and this is the closest place</i>
<i>to their feeding grounds,</i>

298
00:45:46,661 --> 00:45:48,079
<i>where they can find rest.</i>

299
00:46:02,928 --> 00:46:05,972
<i>This calf must stay close to its mother.</i>

300
00:46:14,564 --> 00:46:17,567
<i>But every square inch is occupied.</i>

301
00:46:27,202 --> 00:46:29,120
[grunting]

302
00:46:37,128 --> 00:46:39,923
<i>Climbing over</i>
<i>the tightly packed bodies</i>

303
00:46:40,006 --> 00:46:42,425
<i>is the only way across the crowd.</i>

304
00:46:45,011 --> 00:46:47,472
<i>Those beneath can get crushed to death.</i>

305
00:46:55,939 --> 00:46:58,441
<i>A stampede can occur out of nowhere.</i>

306
00:47:20,463 --> 00:47:25,760
<i>Under these conditions,</i>
<i>walruses are a danger to themselves.</i>

307
00:47:31,600 --> 00:47:35,478
<i>Some manage to find space</i>
<i>away from the crowds.</i>

308
00:47:40,984 --> 00:47:43,695
<i>They struggle up the 80-meter cliffs,</i>

309
00:47:49,576 --> 00:47:54,831
<i>an extraordinary challenge</i>
<i>for a one-tonne animal used to sea ice.</i>

310
00:48:08,178 --> 00:48:10,972
<i>At least up here there's space to rest.</i>
<i>A walrus's eyesight out of water is poor,</i>

311
00:48:23,652 --> 00:48:26,196
<i>but they can sense the others down below.</i>

312
00:48:31,785 --> 00:48:35,497
<i>As they get hungry,</i>
<i>they need to return to the sea.</i>

313
00:49:22,127 --> 00:49:24,295
<i>In their desperation to do so,</i>

314
00:49:24,879 --> 00:49:28,883
<i>hundreds fall from heights</i>
<i>they should never have scaled.</i>

315
00:50:30,945 --> 00:50:36,659
<i>These mass gatherings of walrus</i>
<i>are now happening almost every year.</i>

316
00:50:43,833 --> 00:50:49,464
<i>So the lives of walruses,</i>
<i>like those of polar bears and seals,</i>

317
00:50:49,839 --> 00:50:50,757
<i>are changing.</i>

318
00:50:53,259 --> 00:50:56,679
<i>All are living at the frontier</i>
<i>of climate change,</i>

319
00:50:58,765 --> 00:51:01,434
<i>and all are suffering as a consequence.</i>

320
00:51:20,078 --> 00:51:26,376
<i>For now, the Arctic winter returns</i>
<i>and the sea ice reforms.</i>

321
00:51:28,586 --> 00:51:30,713
<i>Order is restored.</i>

322
00:51:34,843 --> 00:51:39,305
<i>Relief for the many creatures</i>
<i>that depend on the ice.</i>

323
00:51:52,610 --> 00:51:54,320
<i>But for how much longer</i>

324
00:51:54,696 --> 00:52:00,243
<i>will their frozen worlds</i>
<i>be a part of life on our planet?</i>

325
00:52:18,428 --> 00:52:20,513
<i>Please visit ourplanet.com</i>

326
00:52:20,805 --> 00:52:25,226
<i>to discover what we need to do now</i>
<i>to keep the polar wilderness.</i>

327
00:52:27,770 --> 00:52:33,610
<i>♪ I can hear the whole world</i>
<i>Singing together ♪</i>

328
00:52:36,321 --> 00:52:42,160
<i>♪ I can hear the whole world</i>
<i>Say it's now or never ♪</i>

329
00:52:44,996 --> 00:52:49,375
<i>♪ 'Cause it's not too late</i>
<i>If we change our ways ♪</i>

330
00:52:49,459 --> 00:52:52,962
<i>♪ And connect the dots to our problems ♪</i>

331
00:52:53,296 --> 00:52:59,052
<i>♪ I can hear the whole world</i>
<i>Say we're in this together ♪</i>