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(air whooshing)

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Bleak to the extreme,

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harking back to the struggles of the last great ice age.

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The Tundra pushes life to the limits.

5
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(soft music)

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But with the most dramatic seasonal changes.

7
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(soft music)
(birds chirping)

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It offers rich rewards,

9
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but those tough enough to take on the challenge.

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The creatures here are some of the toughest,

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most highly adapted,

12
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and fascinating,

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all playing a role in balancing a delicate landscape.

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(birds chirping)

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One that despite its remoteness,

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is already coming under pressure from us.

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The Tundra, is a landscape which affects us all

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in ways we are only just coming to understand.

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(wolf howling)

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Maybe we can learn from its hardy inhabitants.

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(horns clacking)

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(wind whistling)

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(birds cawing)

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If you travel north across our planet

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somewhere around latitude 60 and 70 degrees

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you'll run out of forest.

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Beyond them, a drying hostile barren

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and bitterly cold wasteland,

29
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too harsh even for trees to take root.

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(air whooshing)

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(soft music)

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This is the Tundra,

33
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a word that means barren, treeless plains.

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It straddles North America and Eurasia,

35
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making a great icy ring around the Arctic.

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The coldest driest habitat on earth might appear lifeless

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but look again.

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(soft music)

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Looking tiny, insignificant,

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little more than a glorified hamster,

41
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lemmings are anything but.

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They must be one of the toughest creatures on earth.

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One of very few mammals

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that thrive on the Tundra year round.

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The miniature models are actually vital,

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pillars supporting an entire plant and animal community.

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During winter, they dig tunnels under the snow

48
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using the white blanket to trap heat

49
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while they forage on the Tundra's surface as normal.

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Most rodents could not do this.

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Winter temperatures hover around -35 to -45 degrees Celsius.

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For most little mammals, life here would be impossible.

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And for the few that can make it,

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the only option in winter is hibernation.

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For the eight crippling months of winter,

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the Arctic ground squirrel escapes to a world of fairy tales

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in a long, deep slumber.

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Slowing his metabolism, lowering his heartbeat,

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he can actually let his body drop below freezing.

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Occasionally he shivers,

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a little fidget is enough to keep him alive,

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while winter surges overhead.

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For more than half a year, winter owns this wasteland.

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At its heart the Tundra endures weeks of darkness,

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where the sun's arc is too low to break the horizon.

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Without light, no plants can grow.

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There is zero productivity.

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This is the ultimate test of life.

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(wolf howling)

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And yet life endears.

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For the hardy, a globe gradually returns to the horizon.

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Muskox had been fighting against the hardships of winter

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here for tens of thousands of years,

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leftovers from the time mammoths roamed these parts.

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Their shaggy coats are their greatest defense.

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They are wrapped in quilts of wool, known as qiviut,

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which is said to be eight times warmer than sheep's wool.

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The long curtain of guard hairs over the top

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helps rain runoff and act as a windbreak.

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Ice crystals form in their curtains of hair.

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They huddle in larger groups to help conserve their heat,

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though the proximity isn't always easy.

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Food is incredibly scarce.

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Huge horns and giant hooves service snowplows

85
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to dig and expose what they can.

86
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But there's a strict hierarchy,

87
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and with competition for meager resources, tempers fray

88
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(soft music)

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But the light is slowly gaining strength.

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The first feeble beams of sun offer respite

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to their cold bodies,

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a promise that better times approach.

93
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As the hours of daylight gradually build,

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activities beneath the snow change.

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(soft music)

96
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Lemmings like a bit of personal space,

97
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but in snow tunnels it's not always an option.

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But the rising temperatures and sunlight

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trigger hormone changes

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that make the rodents a little more feisty.

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A desire to breed causes a bit of friction

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and eventually the need comes to make a break for freedom.

103
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Dashing from colony to colony,

104
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they can seek some positive interactions.

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For the little male, every household has mating promise,

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but also the chance of competition.

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Like speed dating, he dashes on,

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hoping for a better outcome in this lemming lucky day.

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His efforts are being watched.

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Arctic foxes are just one other of a tiny handful of species

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that stick out Tundra winters.

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(soft music)

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Many molt to white coats for winter to blend into the snow.

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This one is part of the exclusive one percent

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that stayed dark year round, known as blue wolf.

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It's still cold.

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Instead of wasting precious energy

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dashing after turbocharged lemmings,

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she turns to her fridge freezer.

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Arctic foxes are experts in collecting food

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and stashing it for later.

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The success of Lemmings can have a massive impact

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on the fortunes of foxes and other predators.

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She plays maybe warming herself up

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or perhaps she's trying to defrost her meal.

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(soft music)

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The reason these rodents tunnel above the ground

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instead of below it,

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is that it would be like digging into concrete.

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One thing that defines Tundra is the presence of permafrost.

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Though the very top layer of soil,

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10 or 15 centimeters deep,

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might defrost and refreeze each year,

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below that, the earth is frozen solid

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to depths of up to 1,000 meters

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and has been for thousands of years.

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It's this IC barrier to the underworld

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that prevents tree roots from taking hold.

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Creating the uniquely open icy Tundra,

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ice locked barren and inhospitable,

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it doesn't look very appealing,

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but this is a dynamic landscape.

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It only takes the sun to rise a few degrees

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above the horizon and the Tundra Springs to life.

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At first it's quiet, a few residents that weathered winter

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make the most of the weak sun.

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Muskox shovel the slightly softening snow

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to see what they can find.

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And the paths they clear create opportunities for others.

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Arctic hares in winter white coats,

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nibble at any exposed plants the giants have unearthed.

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The hares are good diggers too, and need to be.

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Compared to other Tundra specialists,

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they can only store limited amounts of fat on their bodies.

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During winter storms,

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they dig holes into the snow to take shelter

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but the rest of the time they stick it out.

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As hares go, they're short legged and have smaller ears,

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reducing the amount of surface exposed to the frigid air.

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Though they are leafy eaters, like other hares and rabbits,

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they'll make the most of what they find,

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even nibbling dead animals or fish.

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The squirrels have been sleeping soundly beneath their feet,

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but now groggy ground squirrels are beginning to stir.

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But there's no time for lazy lions.

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(birds chirping)

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Summers go fast here,

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so for animals to stand a chance of breeding

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they need to be quick.

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Ground squirrels have just a few weeks

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when females are receptive,

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so this male needs to get busy.

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(birds chirping)

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Finding a date is the easy part.

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It's jealous boyfriends that presents the challenge.

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The male splashes himself with aftershave

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from a gland on his tail.

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It doesn't go down well,

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jealous squirrels go nuts.

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(suspenseful music)

181
00:17:27,736 --> 00:17:32,569
But the stakes are high, not only risking physical injury,

182
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but also this year's chance to be a dad.

183
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It's time for a new chapter on the Tundra.

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Here there isn't much in the way of Spring or Autumn,

185
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just a really long Winter and a short burst of Summer

186
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that no one can afford to miss.

187
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(birds chirping)

188
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(water dripping)

189
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(wind blowing)

190
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As the snow melts, the lemmings find themselves homeless.

191
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Their tunnels collapse around them,

192
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leaving them exposed and vulnerable.

193
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So they need to get busy

194
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looking for natural bolt holes in rocks.

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(soft music)

196
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As the tunnels vanish, the lemming leftovers are revealed

197
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and this is a vital clue into the Tundra's richness.

198
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Soil hair is thin, frozen and of poor quality.

199
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But lemmings are so abundant and busy year round

200
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that they have scattered a thin layer of fertilizer

201
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all over the Tundra's surface.

202
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It's the fertilizer all plants are going to need

203
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as the growing season gets underway.

204
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The thinning snow reveals a brown and empty wasteland,

205
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but not for long.

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With only a few precious months of sunlight,

207
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plants that have laid dormant in the soil waste no time.

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Most of them spend summer producing food from sunlight

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but storing it underground in their roots,

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ready to push forth the following season.

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With no time to waste in producing offspring

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they explode with flowers,

213
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carpeting the Tundra in rainbow colors.

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Flowers need pollinators and no sooner than they bloom,

215
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as if by magic insects appear.

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(flies buzzing)

217
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It's a miracle of the Tundra

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that such tiny, delicate animals can survive here.

219
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Some 2,000 species of insects call Tundra home.

220
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Many of them overwintered by shutting down their bodies

221
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and lying dormant.

222
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The most abundant of bugs are midges and mosquitoes.

223
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They convert the water in their bodies to glycerol,

224
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which acts like a natural antifreeze.

225
00:22:00,672 --> 00:22:03,135
The bees here are hairier for warmth,

226
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flapping their wings creates heat

227
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and the fur helps to store it in their bodies.

228
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Each with their own defenses against the cold,

229
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these tiny creatures get to work,

230
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pollinating the abundant plant life.

231
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(soft music)

232
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They are joined by visitors from the other end of the world,

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long tailed skewers.

234
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After a winter spent at sea, plundering the Southern oceans

235
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where they are known as pirates for their habit

236
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of bullying other birds to steal their food,

237
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this aggressive pair have come here to breed.

238
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After an incredible 10,000 kilometer journey,

239
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they waste no time in making their arrival felt.

240
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The snowy owl sometimes slip to the nearest forests

241
00:23:26,032 --> 00:23:30,492
to shelter in winter, which is toughed out on the snow,

242
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which means they are here at the start of summer

243
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and ready to breed,

244
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but they don't have the place to themselves.

245
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The skewers are laying out a perimeter fence

246
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around their proposed nesting site.

247
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Boundary lines that they will uphold at any cost.

248
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(birds cawing)

249
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Not a great way to build relations with their new neighbors.

250
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Though scavengers and fish eaters at sea,

251
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here the skewers become deadly predators

252
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and rodents specialists,

253
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spreading fear through the lemming colony.

254
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The vanishing snow leaves them exposed

255
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easily spotted by the aerial raids.

256
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Caught in the open, it tries to keep a low profile.

257
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Fortunately there are still a few patches of deepest snow.

258
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A second lemming is less fortunate.

259
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The perfect picnic.

260
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Best shared.

261
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Life is challenging for the lemmings.

262
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The snow is melting, but the ground beneath is frozen.

263
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There's nowhere for the water to run.

264
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So it pools on the surface.

265
00:26:18,862 --> 00:26:21,382
Another Tundra characteristic,

266
00:26:21,382 --> 00:26:25,485
over summer, much of it is a giant bulky wetland.

267
00:26:30,862 --> 00:26:33,345
Fortunately, lemmings are good swimmers.

268
00:26:38,032 --> 00:26:41,315
Invertebrate life flourishes in the pockets of water.

269
00:26:59,442 --> 00:27:01,132
It's the perfect breeding ground

270
00:27:01,132 --> 00:27:03,055
for mosquitoes and other bugs.

271
00:27:07,005 --> 00:27:12,005
(water splashing)
(bugs buzzing)

272
00:27:17,492 --> 00:27:19,472
The growing insect population

273
00:27:19,472 --> 00:27:21,265
is starting to attract a crowd.

274
00:27:22,304 --> 00:27:24,522
(birds cowing)

275
00:27:24,522 --> 00:27:27,975
The start of summer is the start of Tundra rush hour.

276
00:27:34,092 --> 00:27:36,282
Hundreds of thousands of birds

277
00:27:36,282 --> 00:27:39,875
who moved south to escape the winter now flock back.

278
00:27:45,032 --> 00:27:48,362
Arctic summers get long hours of sunlight,

279
00:27:48,362 --> 00:27:52,685
fueling plant growth, feeding a blossoming insect community.

280
00:27:54,782 --> 00:27:57,755
This is the perfect place for birds to raise their young.

281
00:28:02,312 --> 00:28:04,215
A lot of small waiting birds;

282
00:28:05,552 --> 00:28:06,385
plovers,

283
00:28:08,962 --> 00:28:09,932
turnstones

284
00:28:12,062 --> 00:28:12,895
and knot,

285
00:28:15,432 --> 00:28:17,495
and ducks, and geese.

286
00:28:19,892 --> 00:28:22,645
An Ida duck nests close to the skewers.

287
00:28:24,392 --> 00:28:25,735
It's a bit of a headache,

288
00:28:27,352 --> 00:28:30,765
but she chose nasty neighbors over the alternative.

289
00:28:33,472 --> 00:28:35,135
There are no trees on the Tundra,

290
00:28:35,972 --> 00:28:39,962
birds have no choice other than to nest on the ground

291
00:28:39,962 --> 00:28:42,075
and predators are abundant.

292
00:28:45,712 --> 00:28:49,322
The ida knows it's in for some regular dive bombing

293
00:28:49,322 --> 00:28:52,235
but so is anything else that comes too close.

294
00:28:56,322 --> 00:28:59,392
Arctic foxes are one of the biggest threats

295
00:28:59,392 --> 00:29:01,115
to the ground nesting birds.

296
00:29:04,002 --> 00:29:05,335
Most are vulnerable.

297
00:29:09,345 --> 00:29:12,012
(fox grumbling)

298
00:29:14,135 --> 00:29:15,468
But not skewers.

299
00:29:17,722 --> 00:29:20,935
These confident aerial acrobats mean business.

300
00:29:22,692 --> 00:29:25,109
(soft music)

301
00:29:29,402 --> 00:29:32,792
So while the ida lives in a rowdy neighborhood,

302
00:29:32,792 --> 00:29:34,945
she knows her nest is well guarded.

303
00:29:38,202 --> 00:29:40,865
But that doesn't mean she's in for an easy ride.

304
00:29:44,691 --> 00:29:49,691
(soft music)
(birds chirping)

305
00:29:52,842 --> 00:29:55,352
It's still early in the season.

306
00:29:55,352 --> 00:29:57,392
The weather is unpredictable

307
00:29:57,392 --> 00:30:00,065
and winter is ready to leap back in an instant.

308
00:30:08,962 --> 00:30:11,685
All of the animals will feel the Arctic's fury.

309
00:30:13,710 --> 00:30:16,293
(birds cowing)

310
00:30:18,232 --> 00:30:22,082
The Ida's eggs would freeze and die instantly,

311
00:30:22,082 --> 00:30:24,855
only her body heat can keep them alive.

312
00:30:29,312 --> 00:30:32,102
So she has no choice other than to sit tight

313
00:30:32,102 --> 00:30:33,252
and let the snow build.

314
00:30:35,679 --> 00:30:38,096
(soft music)

315
00:30:44,472 --> 00:30:47,475
The Tundra is transformed back to a winter white out.

316
00:30:56,282 --> 00:30:58,062
But putting up with the code

317
00:30:58,062 --> 00:31:01,465
is the trade-off for food and sunlight in abundance.

318
00:31:06,337 --> 00:31:08,920
(birds cowing)

319
00:31:13,102 --> 00:31:16,402
Another strategy for keeping your family safe

320
00:31:16,402 --> 00:31:20,455
is to band together and present a united front.

321
00:31:21,622 --> 00:31:23,905
That is the strategy for snow geese.

322
00:31:28,262 --> 00:31:30,062
A wolf could certainly snag a goose,

323
00:31:32,172 --> 00:31:34,185
but only with the element of surprise.

324
00:31:35,922 --> 00:31:38,975
The alert flock spots him in plenty of time.

325
00:31:40,601 --> 00:31:43,018
(soft music)

326
00:31:44,392 --> 00:31:48,522
Calmly they keep enough distance to allow a takeoff

327
00:31:48,522 --> 00:31:49,945
if he gets too close.

328
00:31:53,902 --> 00:31:57,865
parting the sea before him, the Wolf carries on his way.

329
00:32:06,413 --> 00:32:08,996
(wolf howling)

330
00:32:15,202 --> 00:32:17,085
The wolves pack is nearby.

331
00:32:20,912 --> 00:32:22,852
The family has cubs

332
00:32:22,852 --> 00:32:24,945
and everyone is expected to protect them.

333
00:32:28,495 --> 00:32:29,995
But they are caught off guard.

334
00:32:34,312 --> 00:32:36,192
Now that it's warmer,

335
00:32:36,192 --> 00:32:39,215
the musk ox herds are broken into small groups.

336
00:32:42,552 --> 00:32:46,585
The big adult males are mostly solitary and roam the plains.

337
00:32:48,662 --> 00:32:52,095
And this one has roamed into the heart of the packs home.

338
00:32:54,322 --> 00:32:56,685
This is a delicate situation.

339
00:32:59,972 --> 00:33:03,922
Buffalo on the African plains will kill lion cubs

340
00:33:03,922 --> 00:33:06,505
stopping a potential threat in its tracks.

341
00:33:09,982 --> 00:33:13,015
The muskox could easily do the same now.

342
00:33:16,422 --> 00:33:19,655
He weighs as much as the entire wolf pack combined.

343
00:33:21,842 --> 00:33:25,075
The last thing they want to do, is make him angry.

344
00:33:30,252 --> 00:33:32,515
The pups are clearly nervous,

345
00:33:36,662 --> 00:33:38,755
but everyone tries to remain calm.

346
00:33:43,262 --> 00:33:45,982
It's not ideal for the muskox either.

347
00:33:45,982 --> 00:33:48,595
He's surrounded by his main enemy.

348
00:33:53,172 --> 00:33:57,055
One of the adults ushers the pups to a safer hiding spot.

349
00:34:01,762 --> 00:34:02,845
Almost there.

350
00:34:10,612 --> 00:34:15,612
But as a departing gesture, the bull makes a statement.

351
00:34:21,142 --> 00:34:22,245
Don't mess with me.

352
00:34:54,452 --> 00:34:57,555
Point taken, the wolves politely step aside.

353
00:35:01,422 --> 00:35:04,182
The stakes are too high on both sides.

354
00:35:04,182 --> 00:35:07,345
And the intense encounter is brought to a close.

355
00:35:14,013 --> 00:35:15,432
(soft music)

356
00:35:15,432 --> 00:35:17,305
There are babies all over the place,

357
00:35:24,712 --> 00:35:28,445
but the prize for productivity goes to the lemmings.

358
00:35:36,442 --> 00:35:38,352
Unlike most animals here,

359
00:35:38,352 --> 00:35:41,192
they are not tied to a breeding season,

360
00:35:41,192 --> 00:35:43,545
and can churn out youngsters year round.

361
00:35:52,322 --> 00:35:54,432
With half a dozen or more babies delivered

362
00:35:54,432 --> 00:35:55,882
every month or so,

363
00:35:55,882 --> 00:35:58,322
and each being able to breathe for themselves

364
00:35:58,322 --> 00:36:00,342
at just a month old,

365
00:36:00,342 --> 00:36:04,165
lemming populations are limited only by food.

366
00:36:06,334 --> 00:36:08,751
(soft music)

367
00:36:14,632 --> 00:36:18,062
On lean years their populations shrink,

368
00:36:18,062 --> 00:36:20,495
but on a good year can explode.

369
00:36:25,532 --> 00:36:28,312
And the abundance of rodents is critical

370
00:36:28,312 --> 00:36:31,615
to successful breeding seasons for the Tundra's predators.

371
00:36:34,942 --> 00:36:37,912
Many populations like the snowy owls

372
00:36:37,912 --> 00:36:40,262
will go through the same peaks and trumps

373
00:36:40,262 --> 00:36:42,485
in response to the numbers of lemmings.

374
00:36:47,592 --> 00:36:50,412
Even a good year won't ensure the survival

375
00:36:50,412 --> 00:36:51,805
of all of the outlets.

376
00:36:55,402 --> 00:36:58,072
They have an unusual insurance strategy,

377
00:36:58,072 --> 00:37:00,115
having more chicks than they need.

378
00:37:03,082 --> 00:37:06,085
The oldest and biggest always gets fed first,

379
00:37:08,512 --> 00:37:10,542
though if something happens to it,

380
00:37:10,542 --> 00:37:12,395
they prioritize the next in line.

381
00:37:14,952 --> 00:37:16,662
With this favoritism,

382
00:37:16,662 --> 00:37:19,545
the youngest in the family rarely survive.

383
00:37:25,522 --> 00:37:30,182
The skewers keep it simple, with just one or two chicks,

384
00:37:30,182 --> 00:37:31,572
and the mother guarding

385
00:37:31,572 --> 00:37:33,672
while the father does most of the hunting.

386
00:37:36,897 --> 00:37:40,202
(upbeat music)

387
00:37:40,202 --> 00:37:43,425
Of course, both are quick to defend their young.

388
00:37:49,712 --> 00:37:53,615
At just a few days old, the chicks know to flee the nest.

389
00:37:55,022 --> 00:37:56,362
Having both in one place

390
00:37:56,362 --> 00:37:58,365
makes them more at risk of disaster,

391
00:37:59,252 --> 00:38:00,925
they can spread out and hide.

392
00:38:03,352 --> 00:38:06,302
but the parents aren't going to let any intruders through.

393
00:38:23,623 --> 00:38:27,706
The chicks don't have to brave the cold for long.

394
00:38:29,126 --> 00:38:31,876
(birds chirping)

395
00:38:47,982 --> 00:38:51,225
Their nesting grounds are visited by passing nomads.

396
00:38:54,512 --> 00:38:57,142
Only one day a thrives on the Tundra,

397
00:38:57,142 --> 00:38:59,632
known as reindeer across Eurasia

398
00:38:59,632 --> 00:39:01,615
and caribou in North America.

399
00:39:03,672 --> 00:39:07,292
They are perpetual travelers, always on the move,

400
00:39:07,292 --> 00:39:10,622
following the seasonal growth to survive harsh conditions

401
00:39:10,622 --> 00:39:12,095
and find the best food.

402
00:39:16,422 --> 00:39:20,075
But for the herds and all life here, things are changing.

403
00:39:22,479 --> 00:39:24,896
(soft music)

404
00:39:28,442 --> 00:39:32,065
Many herds of caribou and reindeer are decreasing.

405
00:39:37,072 --> 00:39:38,942
They are suffering from increased numbers

406
00:39:38,942 --> 00:39:40,855
of parasites and diseases.

407
00:39:45,032 --> 00:39:49,085
The pests are building up because of a milder climate.

408
00:39:50,262 --> 00:39:53,922
Because of climate change, accelerated by human activities

409
00:39:53,922 --> 00:39:56,662
that plow carbon into the atmosphere,

410
00:39:56,662 --> 00:40:00,115
the Tundra is under threat and changing fast.

411
00:40:04,252 --> 00:40:08,362
Polar bears are often considered marine animals.

412
00:40:08,362 --> 00:40:11,139
They spend their winters out on the sea ice.

413
00:40:15,212 --> 00:40:17,682
In summer, they are landlocked

414
00:40:17,682 --> 00:40:20,355
and forced to search for food on the Tundra.

415
00:40:25,552 --> 00:40:27,922
We all know about shrinking sea ice

416
00:40:27,922 --> 00:40:30,395
and the problems it causes for the bears,

417
00:40:31,892 --> 00:40:35,432
but it's changing things for them on the Tundra as well,

418
00:40:35,432 --> 00:40:38,182
with both summers and winters milder

419
00:40:38,182 --> 00:40:41,522
than they have been for millions of years.

420
00:40:41,522 --> 00:40:44,822
The Tundra is not as inhospitable

421
00:40:44,822 --> 00:40:45,885
as it used to be.

422
00:40:46,832 --> 00:40:50,755
Creatures less adapted to the poles are able to move in.

423
00:40:51,692 --> 00:40:54,132
Grizzly bears are making themselves more at home

424
00:40:54,132 --> 00:40:58,995
in the extreme north, and they can breed with polar bears.

425
00:41:00,152 --> 00:41:04,342
Their offspring known as pizzly or grolar bears

426
00:41:04,342 --> 00:41:07,005
are diluting the polar bears pure gene pool.

427
00:41:21,912 --> 00:41:24,732
Arctic foxes face a similar problem

428
00:41:26,712 --> 00:41:28,812
where once they had the monopoly,

429
00:41:28,812 --> 00:41:30,952
truly the only small predators

430
00:41:30,952 --> 00:41:33,372
that could handle life on the Tundra,

431
00:41:33,372 --> 00:41:35,445
now they have competition,

432
00:41:37,882 --> 00:41:41,042
an invasion of red foxes.

433
00:41:41,042 --> 00:41:45,122
And these larger, more wily cousins will drive them off,

434
00:41:45,122 --> 00:41:47,522
out competing and in some places

435
00:41:47,522 --> 00:41:50,205
reducing the Arctic fox population.

436
00:41:56,142 --> 00:42:00,742
It's not just animals, plants like trees and bushes,

437
00:42:00,742 --> 00:42:02,785
are able to grow much further north.

438
00:42:06,422 --> 00:42:09,062
The Tundra is being modified,

439
00:42:09,062 --> 00:42:12,626
the impact of which will be felt all over the world.

440
00:42:12,626 --> 00:42:15,376
(air whooshing)

441
00:42:17,822 --> 00:42:20,032
For several million years

442
00:42:20,032 --> 00:42:22,675
the Tundra has been a carbon sink.

443
00:42:25,502 --> 00:42:28,192
Carbon collected from the air by plants

444
00:42:28,192 --> 00:42:31,042
is transported into the ground.

445
00:42:31,042 --> 00:42:35,212
But because of the permafrost, plant remains are frozen,

446
00:42:35,212 --> 00:42:38,855
they can't rot, so the carbon can't be released.

447
00:42:40,062 --> 00:42:42,895
(water splashing)

448
00:42:45,302 --> 00:42:48,052
Now, because of climate change,

449
00:42:48,052 --> 00:42:52,577
the Tundra's permafrost is melting more and more every year.

450
00:42:52,577 --> 00:42:55,410
(birds whistling)

451
00:42:57,882 --> 00:43:02,882
Thousands of years worth of stored carbon is being released.

452
00:43:03,366 --> 00:43:06,199
(water splashing)

453
00:43:09,052 --> 00:43:13,422
And worse still, because the Tundra is so boggy,

454
00:43:13,422 --> 00:43:17,452
a lot of the rotting takes place in low oxygen bulks,

455
00:43:17,452 --> 00:43:21,555
where instead of carbon dioxide, methane is released.

456
00:43:26,481 --> 00:43:29,401
(water dripping)

457
00:43:29,401 --> 00:43:32,151
(air whooshing)

458
00:43:33,622 --> 00:43:36,465
Carbon dioxide is a major greenhouse gas,

459
00:43:38,512 --> 00:43:42,302
but methane is 25 times worse.

460
00:43:42,302 --> 00:43:44,772
And the release of all this Tundra gas

461
00:43:44,772 --> 00:43:49,032
will just fuel the change, accelerating global warming.

462
00:43:49,973 --> 00:43:52,473
(soft music)

463
00:43:56,412 --> 00:43:59,552
The Tundra has always been a carbon sink

464
00:43:59,552 --> 00:44:02,472
containing one and a half times the carbon

465
00:44:02,472 --> 00:44:04,335
of our entire atmosphere.

466
00:44:07,732 --> 00:44:11,292
But it's melting is flipping this great asset

467
00:44:11,292 --> 00:44:16,292
from a carbon sink to a carbon source and a great threat.

468
00:44:18,359 --> 00:44:21,142
(water splashing)

469
00:44:21,142 --> 00:44:24,222
All of us should be very worried about the impact

470
00:44:24,222 --> 00:44:27,682
of the Tundra's health on the world's climate,

471
00:44:27,682 --> 00:44:31,732
which is already unstable and threatening all life,

472
00:44:31,732 --> 00:44:33,115
including ours.

473
00:44:34,675 --> 00:44:37,092
(soft music)

474
00:44:40,712 --> 00:44:42,665
And for the wildlife of the Tundra,

475
00:44:43,692 --> 00:44:46,012
it already has enough to deal with

476
00:44:46,012 --> 00:44:47,932
just trying to make it through the year,

477
00:44:47,932 --> 00:44:50,415
living in the most challenging habitat.

478
00:44:56,542 --> 00:45:00,465
The growing season on the Tundra lasts only two months.

479
00:45:04,072 --> 00:45:07,515
In the blink of an eye, the evenings are creeping in.

480
00:45:11,862 --> 00:45:15,085
Change is in the air.
(birds cawing)

481
00:45:28,312 --> 00:45:29,832
The Tundra provides wealth

482
00:45:29,832 --> 00:45:31,585
for those willing to tough it out,

483
00:45:32,922 --> 00:45:37,542
and in a final act of generosity, produces a sea of berries

484
00:45:37,542 --> 00:45:40,235
just in time for the ground squirrels to bulk up.

485
00:45:45,322 --> 00:45:49,022
The Arctic fox's cubs are all but ready to leave home

486
00:45:49,022 --> 00:45:50,272
and are figuring out

487
00:45:50,272 --> 00:45:52,835
what they can and can't eat on the Tundra.

488
00:45:53,777 --> 00:45:56,194
(soft music)

489
00:46:08,043 --> 00:46:10,292
Muskox are probably off the menu,

490
00:46:13,222 --> 00:46:16,125
but still it's fun to wind these giants up.

491
00:46:20,882 --> 00:46:24,422
The rich carpet of mosses, lichens, and fungi

492
00:46:24,422 --> 00:46:26,435
have also fueled the muskox herd,

493
00:46:28,897 --> 00:46:31,397
(Ox sniffing)

494
00:46:33,502 --> 00:46:36,325
energy they now need for their rut.

495
00:46:42,532 --> 00:46:44,402
Sharp horns point forwards

496
00:46:45,662 --> 00:46:48,862
and a horny boss, a massive matted hair

497
00:46:48,862 --> 00:46:52,825
forms a crash helmet and shield to absorb any blow,

498
00:46:57,352 --> 00:46:59,462
which is just as well.

499
00:46:59,462 --> 00:47:00,945
Let the games begin.

500
00:47:04,746 --> 00:47:07,329
(upbeat music)

501
00:47:29,312 --> 00:47:33,614
But soon waves of sleet put a cooler on their games.

502
00:47:33,614 --> 00:47:36,031
(soft music)

503
00:47:45,906 --> 00:47:48,656
(air whooshing)

504
00:47:52,492 --> 00:47:54,075
The days are getting shorter.

505
00:47:56,432 --> 00:47:59,983
It's time for most species to escape.

506
00:47:59,983 --> 00:48:03,102
(bird cowing)

507
00:48:03,102 --> 00:48:08,102
Birds head south, lands begin to wither under the frost.

508
00:48:11,912 --> 00:48:14,052
Cocooned in their mossy nests,

509
00:48:14,052 --> 00:48:16,782
the ground squirrels slow their metabolisms,

510
00:48:16,782 --> 00:48:19,745
ready to skip the winter in their peaceful slumber.

511
00:48:26,566 --> 00:48:28,983
(soft music)

512
00:48:30,282 --> 00:48:31,752
The tougher residents

513
00:48:31,752 --> 00:48:35,005
prepare for another long, dark, lonely winter.

514
00:48:36,382 --> 00:48:38,799
(soft music)

515
00:48:40,562 --> 00:48:44,182
And the lemmings literally laying the foundations

516
00:48:44,182 --> 00:48:47,272
of the Tundra, both through the food chain

517
00:48:47,272 --> 00:48:51,185
and ground fertilization, carry on like normal,

518
00:48:54,952 --> 00:48:57,325
but under their sky of snow.

519
00:49:03,082 --> 00:49:06,112
As darkness claims the Tundra once again,

520
00:49:06,112 --> 00:49:11,112
these hardy and iconic animals face an uncertain future,

521
00:49:15,252 --> 00:49:17,612
especially if they can't count on us

522
00:49:17,612 --> 00:49:20,155
to reduce our impact on the environment,

523
00:49:23,792 --> 00:49:25,775
and to their Tundra home.

524
00:49:31,208 --> 00:49:33,708
(soft music)