Original subtitles

Looking down on our planet, it may come as a surprise

to find just how much of it is blanketed in snow and ice.

These vast frozen wildernesses cover more than a fifth of the Earth...

...yet some areas are so remote and inhospitable that, even today,

the closest we've come to exploring them is from space.

More than a decade ago, the first series of Frozen Planet

examined life in the Arctic and the Antarctic.

In this series, we will explore all of Earth's frozen habitats...

...from its highest peaks,

to its snowbound deserts...

...to deep beneath the ice.

Between them, they contain an astonishing array of animals...

...many that are found nowhere else on Earth.

We will watch the extraordinary ways

by which they manage to survive.

Using new technology, such as racer drones,

we'll gain a new insight into their remarkable lives.

But just as we're beginning to understand its wildlife,

we are recognising an alarming truth.

Our frozen wildernesses are disappearing

at faster rates than ever before.

And never has it been more important to understand

what is going on in these icy territories.

In this first episode, we will travel from pole to pole...

...to celebrate the precious wildlife

found in our frozen wildernesses...

...and witness their wonders...

...while there is still time to save them.

This is Frozen Planet II.

We begin our journey in the far south of the planet.

After six months of darkness, the sun is starting to return

to the largest frozen expanse on Earth...

...Antarctica -

a continent almost twice the size of Australia.

Here, temperatures fall to. - 80 degrees centigrade.

It's the coldest place on Earth.

There is only one animal here hardy enough

to raise its family in winter...

...the emperor penguin.

Winds here can reach speeds of over 100mph,

and a chick is in real danger of freezing to death.

But his parents are possibly the most devoted in all nature.

They shield him from the full force of the icy blast...

...and huddle together to create a tight creche.

Within it, the chicks, remarkably, can maintain their body temperature

of 37 degrees Celsius.

Until one spring day,

when the chicks have grown to almost a metre tall...

...the parents simply walk away.

Their parental duties are complete...

...and they will never again return to their chicks.

As the days pass, the chicks grow hungry...

And their only chance of finding a meal is out at sea...

...but that could be 30 miles away across the frozen ocean.

When one makes the first bold move...

...the rest follow.

They set off at a steady pace.

But sliding on your belly is an easy option.

Out on this ever-changing platform of the frozen sea...

...towering walls of ice stand in their way.

This will require mountaineering skills.

Beaks come in useful as ice-picks.

And tobogganing is a quick way down.

As they near the sea, the ice becomes more unstable.

Even the smallest crack is met with suspicion.

And with good reason.

A crack can quickly turn into a gaping chasm.

If they can't escape, the panicked chicks will be doomed.

Made it.

Finally, the end is in sight.

The Southern Ocean.

In some years, the sea ice is so unstable

that none make it as far as this.

These chicks are the lucky ones.

Not the most graceful entry.

But they are in their element...

...the sea.

They may have endured the toughest of upbringings,

but now they can reap the benefits of the long summer ahead

and feed in the richest waters on Earth.

In winter, the seas around Antarctica are so cold

that they form a platform of ice twice the size of Europe.

But in summer, just off the shores of the Antarctic Peninsula,

the ice cover breaks up into millions of tiny ice floes.

It's an excellent place for a Weddell seal

to rest up after a night's feed.

The bay is sheltered...

...and the water calm.

But there are great dangers here.

Killer whales.

This pair of 15-year-olds are learning what is perhaps

the most complex hunting technique in nature.

After sizing up their prey...

...they assemble 30 metres away...

...and then launch an attack.

They swim in tandem, synchronising their tail beats...

...to create a wave.

The seal is washed off...

...but it won't give up without a fight.

The seal has escaped...

...this time.

But for the young killer whales, help is at hand.

They live in multi-generational family groups...

...led by an experienced female, who can be over 100 years old.

Helped by her accumulated knowledge,

the whales have become ruthlessly efficient.

They have a 90% hunting success rate.

But a killer whale needs to eat a seal a day...

...so this 14-strong family has a lot of hunting to do.

Spreading out, they spyhop to search the ice floes.

When a seal is spotted,

the scouts alert the family with a rallying call.

But if they are to catch a seal resting on

such a large piece of ice...

...the hunters need to change their tactics.

This time, they produce a sub-surface wave.

It breaks the ice into smaller pieces.

But the seal still has a raft...

...and appears to be protected from any oncoming wave.

The matriarch whale, however, has a plan.

Working in a coordinated way,

the pod push the seal's ice platform

into clearer water.

The matriarch now tries another tactic

which will avoid injury...

...blowing bubbles.

They disorientate the tiring seal.

And the whales move in for the kill.

Only about 100 killer whales in the world hunt using this technique.

It's an ingenious solution to the problem of finding prey

here in the most extreme frozen habitat on Earth.

Antarctica is so cold

because of its position at the far south of the planet.

But travel north, and you'll find other icy worlds

that are created by altitude - in the mountains.

The Andes, in South America,

with its 4,500 miles of snow-covered peaks,

is the longest range on Earth.

These high icy worlds even exist close to the equator,

where the sun is at its hottest - as on Mount Kenya, in Africa.

But the highest mountains of all stretch 1,500 miles across

the north of sub-tropical Asia - the Himalaya.

At the western end, bordering Pakistan,

stand the Karakoram.

They contain more peaks over 8,000 metres high

than any other range on Earth...

...and include K2, which stands over 8,600 metres tall.

The slopes of the Himalaya carry the greatest accumulation

of snow and ice outside the polar regions.

It's an area known as the Third Pole.

But north of the Himalaya,

there are even more surprising frozen worlds created by altitude.

A remote snow-bound desert...

...the Gobi.

And beyond it, a grassy plain that stretches

for 5,000 miles across Central Asia.

It's known as the Great Steppe.

Here, sheltering from the elements in his boulder den,

is a somewhat grouchy resident.

A Pallas's cat.

He has the densest fur of any cat in the world.

Nonetheless, to keep warm, he must catch up to five rodents a day.

Top of the menu are voles...

...and gerbils.

Relative to body size,

Pallas's cats have one of the shortest legs of any cat...

...and that helps by giving them a low profile when stalking.

But it's not so good for wading through deep snow.

Never mind. There are plenty more.

He just needs to stay focused.

Unfortunately, the longer he's out in the snow,

the colder his paws become.

And he has only one way to get the blood circulating again.

That could be one shake too many.

Only one hunt in three by a Pallas's cat is successful.

No wonder he has the reputation of being

the grumpiest cat in the world.

To the north of the steppe, in higher latitudes,

lies yet another frozen world.

The boreal forest.

750 billion snow-covered trees.

It's the largest forest on Earth,

encircling the top of the world

from Europe to Russia,

and across to North America.

At the far eastern end of this vast Siberian forest

lies the hunting ground of one of the world's rarest big cats.

The Siberian tiger.

Illegal hunting and destruction of its habitat

have driven this tiger to the very brink of extinction.

Now fewer than 500 remain in the wild.

Weighing nearly 200kg, it's the largest of all the big cats.

To keep warm, this male must eat 10kg of meat a day.

But in winter, any prey remaining here...

...is all too easily alarmed.

He must patrol his entire 700 square mile territory

if he is to find enough to eat.

PIGS SNORTING

His acute sense of smell tells him that wild pig were here.

TIGER SNUFFLES

He's so hungry that he would tackle even a 150kg black bear.

But it left here months ago...

...leaving only a faint trace of its scent.

In the autumn, bears here escape the coming winter

by hibernating inside caves.

But that wouldn't stop a tiger from trying to catch one.

Remote cameras reveal the bear's whereabouts.

It retreated into the farthest recess months ago.

The tiger is simply too big to reach it.

But ready for every opportunity,

this big cat is able to endure the long Siberian winter.

And as long as this forest is kept free from poachers,

these magnificent tigers have a good chance of surviving.

In the northerly reaches of the boreal forest...

...a strange phenomenon illuminates the night sky.

The Aurora borealis.

Electrically charged particles from the sun

collide with the Earth's atmosphere,

creating this otherworldly display.

Viewed from space, the aurora brings light to the frozen poles,

which otherwise would remain in darkness for almost three months.

This is the Arctic tundra...

...where temperatures can fall to. - 50 degrees Celsius.

With little or no shelter,

few animals can survive the winter here.

But some do.

Muskox.

Relics from the last ice age.

Two layers of fur protect them from temperatures of -30 degrees.

This allows them to give birth in early spring.

At six hours old, a calf is already able to stand...

...ready to follow the herd in the search for fresh grazing.

But until they gain in strength,

they are very vulnerable.

They're being stalked.

Grizzly bears.

Weighing up to 300kg,

they have emerged after six months of hibernation...

...and are extremely hungry.

One gets to within just ten metres...

...and then attacks.

Separated from their mothers,

the newly born are unable to distinguish friend...

...from foe.

The bear instinctively kills every calf it can.

Only a few escape.

But the herd is now far away...

...and he is too weak to follow.

90% of calves do not survive their first year.

Even one without injury stands little chance without its mother.

Reunited.

If just a few calves survive to adulthood,

the future of the herd will be secure.

North of the tundra lies the Arctic Ocean,

surrounded by three continents -

Europe, North America and Asia.

In winter, it remains almost entirely frozen.

But as the spring sunshine finally reaches the northernmost part

of the planet, the sea ice begins to break up.

This marks the start of the breeding season

for male hooded seals.

When they're six years old, the males develop an inflatable nose.

They're ready to breed -

and the bigger their nose,

the more attractive they will be to a female.

And now this one is eager to prove it.

A female has just given birth.

A mother spends a mere four days feeding milk to her pup...

...and then, and only then, will she be ready to mate again.

That is too long for an impatient youngster to wait around.

These females seem to have been claimed by a larger male.

But if this youngster is to breed this year, it's worth a try.

An inflatable nose can also be used

to intimidate a rival.

His bravado pays off.

He must now woo the receptive female.

She seems unimpressed.

But he has another trick.

He has an expandable sac within his left nostril.

What is her verdict?

A sharp nip on the tail...

...and that means no.

With only one day in the year in which to mate,

the female is understandably choosy.

And until the youngster has grown a more impressive balloon,

he's unlikely to be chosen.

SEAL GROANS

No wonder he's deflated.

The spring not only transforms the ocean,

it also triggers an important event

on the biggest of the Arctic's islands.

Greenland - over 1,600 miles long.

It's covered by a single gigantic ice sheet,

the largest in the northern hemisphere.

As spring advances, the surface of the ice melts,

forming crystal-clear lakes...

...up to five miles wide.

Climate change is bringing higher temperatures,

so there is more and more meltwater.

It drains down into the mile-thick ice sheet...

...and a whole chain of events is then triggered.

Time-lapse photography from space reveals what happens next.

The increased meltwater accelerates the ice sheet's slide downhill.

Eventually, it reaches the ocean.

Here, it breaks up into icebergs,

some taller than the Empire State Building.

Greenland is losing its ice six times faster today

than it was 30 years ago.

It alone is responsible for a quarter

of the rise in global sea levels.

Changes in the Arctic are already affecting the lives

of its highly specialised wildlife.

Polar bears.

These one year old twins still rely on their mother for her milk,

protection and crucial survival lessons.

But they have yet to perfect their swimming technique...

...and they can't wait to practise.

The cubs need to be as at home in the water

as they are on the sea ice.

Their mother calls them out.

Until they've accumulated a significant layer of body fat...

...they feel the cold.

A roll in the snow is a good way to dry off.

Then it's back to play...

...while their mother heads off to hunt.

Over the coming months, a mother must provide her cubs

with not just milk, but meat -

and lots of it.

By midsummer, the sea ice has become so thin...

...that her best chance of catching her preferred prey

is by ambushing it from the water.

It's a technique known as aquatic stalking.

She approaches downwind...

...and tries to get within a metre of a bearded seal.

But today there is less sea ice to provide cover,

so she is having to target riskier prey.

The hooded seal.

They are about the same size as the bearded,

but more aggressive and dangerous.

She moves round to the other side.

The Arctic is now warming more than twice as fast

as the rest of the world.

The sea could be ice-free in summer by as early as 2035.

That will make it harder for mother polar bears

to feed themselves...

...let alone their cubs.

Well adapted to live in the cold...

...the animals that inhabit our frozen lands and seas

need one thing more than any other...

...and that is for the planet to stop warming.

It's now up to us to make that happen.

Filming across the length and breadth of our frozen planet,

one of the team's greatest challenges was to capture

the enormity of Greenland's rapidly melting ice sheet.

To do so, the crew launched five separate filming expeditions,

installing specially designed cold-proof time-lapse cameras

that were to run for three years.

Even commissioning satellites to record the big-picture changes.

But the story would be incomplete without documenting

the finale of this event -

the calving of Greenland's Store Glacier...

...a wall of ice over three miles long...

...and towering 120 metres high.

The crew arrive at the height of the summer thaw,

when, at any moment, fracturing ice blocks the size of a small town

may be cast into the sea.

Camping out for the next three weeks,

the team takes advantage of the constant daylight

offered by the far north at this time of the year.

We've got a lot of ice on the glacier, 24 hours a day.

So, yeah, we're poised.

I started at about 8pm, and it's currently, yeah, just after 2:00.

I've got until 4am this morning, I think.

They're hoping to be one of the first film crews

to use a camera drone for unprecedented proximity

and a brand-new perspective.

Yeah, it's going.

It's not long before their new technology is put to the test.

But it quickly reveals its limitations.

The issue with the drone - you've got to turn it on,

get it in the air, and fly it 1.5km to the glacier fronts.

So, if you SEE a calving happening...

...then you're too late.

With a flight time of just 20 minutes,

gauging the moment of take-off is critical.

Yeah, I feel like today just every decision I've made

has been the wrong one.

It's really easy to trick yourself into thinking,

"Oh, it's going to go, it's going to go," so you get out there,

use up a whole drone battery hovering, come back,

and as you're heading back... pfff!

Soon, the team face another problem

that comes with today's warming Arctic.

Unseasonably wet weather makes it impossible to fly the drone,

and acts as a catalyst for further melting.

Absolute racket happening down in...

...the glacier.

Oh, my goodness.

Even if it is a major calving event...

...can't see a thing.

That sound just went on and on.

That one was huge.

After five days of frustration, the fog finally lifts

to reveal the bay choked with giant icebergs.

It appears the crew have missed their opportunity.

The morale of the crew has taken a little bit of a downturn.

Do you know what, I just don't know what to say.

I'm so tired.

To make matters worse, a plague of mosquitoes descends,

further disheartening the exhausted team.

All your senses are all-go all the time,

even when you're trying to sleep, so it's just...

...a bit emotionally draining sometimes.

Then, with just a few shooting days left,

under a warming sun,

the glacier groans and rumbles back into action.

Ooh...

Guys, big one going!

This could be the opportunity they've been waiting for.

Oh, my gosh, look at that! Ah!

A calving event lasting long enough to film from the drone.

But no-one is prepared for the sheer scale of it.

Just layer after layer of ice broke away

and fell into the sea,

and then out came this enormous, skyscraper-sized iceberg,

displacing vast quantities of water

and throwing enormous blocks of ice around like they were nothing.

Sitting here, day after day, crossing your fingers

and hoping that you get a big calving and you see a big event,

and you manage to film it,

and when it does happen, when it does go off,

it's so exciting, and you get the adrenaline.

And then, afterwards, as you're sort of coming down from that,

there's a bitter sweetness to it as you realise that's another piece

of ice that's slowly raising the sea level.

Such imagery provides an invaluable record of the rapid changes

that are now taking place across our frozen planet.

Next time...

...we travel to the Arctic Ocean.

Where life must adapt in a changing world...

...of water and ice.

The Open University has produced a poster exploring how animals

adapt to life in the world's coldest environments.

To order your free copy, please call 0300 303 0553,

or go to bbc.co.uk/frozenplanet2

and follow the links to the Open University.