Original subtitles

In this series, we have explored the Earth's frozen frontiers.

We have celebrated the astonishing variety of animals that are found there.

And revealed the extraordinary ways by which they managed to survive.

At a time when our ice caps are melting faster than

ever before. We will meet the

scientists and people who are dedicating their lives to

protecting our frozen planet. And striving to turn things

around while there is still time to do so. It won't be easy,

but it's doable. It's crucial that we try to understand what

the impact will be, not just for the wildlife and

the people that live there, but for you and for me.

We start our journey in the high Arctic and the vast frozen expanse of Greenland.

This huge island is blanketed by the largest

store of ice in the Northern Hemisphere.

But now, it's shrinking.

Professor Alan Hubbard is a glaciologist, and he's spent

over 30 years studying the movement of ice along Greenland's

coastline. It is quite a

beast of a glacier. It's just growling constantly.

Thundering in the background.

Oh, there we go, bit of activity.

Carving icebergs is a natural

process, but what we've seen in the last 20 years is there's

been much more melt and much more ice carving off, producing huge icebergs.

So it's quite an intimidating place to be hanging out.

One thing in particular

has caused this increase in melting and carving.

We put this weather station here in 2010. ["Pomp and

Circumstance"] And the hottest temperature was two days ago,

at 22.37 degrees centigrade. That is very, very hot for Greenland.

As the ice falls into the ocean, it raises sea levels globally.

These are now rising by an average

of four millimeters a year. A quarter of that comes from the

Greenland ice sheet. And scientists fear that this figure could increase rapidly.

To investigate, Alan has traveled 70 miles inland to the top

of the ice sheet, where the glaciers start their lives as

compacted snow more than a mile thick.

Here, the effects of a warming climate are only too clear.

There are thousands of these beautiful azure blue lakes

littered across the surface of the ice sheet. The surface

has always melted in the summer, but not on this scale.

And Alan wants to know what effect

the increase in meltwater is having on the ice sheet as a

whole. The sheer quantity of water

shifting through this system is crazy.

Powerful torrents of meltwater are boring shafts, known as

moulins, into the ice sheet. This is nuts. This is a moulin

actively being formed, a moulin in genesis.

As we speak, that water is finding the path of least

resistance, sculpting this shaft that's going deep into the

ice.

And here it is, just toppling over a waterfall

edge and dropping into the ice sheet.

But where is all this meltwater going, and what impact is it

having on the structure of the ice sheet? To find out, Alan

decides to climb inside a dried-up moulin. I think I must be

15, 20 meters down here. I'm going to go down a bit further.

It's a very narrow shaft here. It's always been assumed that

the meltwater drains straight down and out of the bottom of

the ice sheet. But what Alan discovers is very different.

I can hear a big amount of water moving in this system. And

the water is starting to spread sideways, laterally, so

the drainage system is obviously complex, it's interlinked.

These observations suggest that the meltwater is branching

out in every direction, causing this once-rigid structure to

destabilize.

It's a bit rotten. Everything's rotting here.

The implications of this are frightening.

Alan believes that as the ice sheet begins to thaw,

it's sliding towards the ocean at a much faster rate.

And he's now confirmed that, using time-lapse, photography.

The ice, the front, can be moving in excess of 20 meters a

day, which is fast. That is a huge quantity of ice straight

into the ocean. Some of Greenland's glaciers are moving

three times faster today than they were 30 years ago. As the

climate's warming, the rate at which this ice sheet flows is

absolutely critical. So whereas at the moment we're thinking

this thing is going to take thousands of years of melt and

disintegrate, if it does move faster and accelerate, it

means centuries.

That is a really contentious and very important question,

because this ice sheet has enough water in it to raise

global sea level by over seven meters, and that's a total disaster for humanity.

Calculations predict that nearly half a billion people

living in coastal communities around the world will be

displaced by flooding by the end of the century. But if the

Greenland ice sheet slips into the ocean more rapidly, this

could all happen far sooner.

Greenland isn't the only large body of ice in the Arctic. In

winter, the ocean here freezes over, creating a cover of ice

larger than the entire United States.

This sea ice has always got smaller in

summer, but today it's rapidly disappearing.

Hotter temperatures are melting it at an unprecedented rate,

with worrying consequences for the wildlife that depends on it.

For half seals, the sea ice is an excellent place for giving birth out of the water.

It provides the defenseless newborn pups with a safe space

for their first six weeks until they're big enough to swim

proficiently.

But with the sea ice disappearing increasingly fast,

will they be able to adapt?

In Canada's Gulf of St. Lawrence, a group of seal biologists are trying to find out.

But the fragile sea ice is a challenging place in which to work.

Go a little further out. To support a two-ton helicopter,

the ice must be at least 30 centimeters thick, and the only

way to find out if that's so is with a

seal. The team are trying to discover where the seals go

when they become independent. So this is a juvenile harp

seal, which is exactly what we've been out on the ice trying

to find a little ago. They're absolutely beautiful. We'll be

putting a satellite transmitter on the top of this animal's

head so that every time the animal comes to the surface we

can get a location estimate for where he is at sea. It

won't harm them in any way, and in return the amount of

information we get from them is invaluable.

It'll be really interesting to see where these animals go

as the ice starts to break up over the coming months. The

results from the study so far do not look encouraging.

Despite migrating huge distances, when the time comes to

have pups of their own, harp seals almost always

return to the area where they themselves were born.

But as the sea ice shrinks, so does its suitability as a nursery.

The problem really comes about if the only ice available in

the traditional areas is very thin. They'll still use that

ice and then you get increased mortality.

In short, the pups risk drowning if the ice isn't thick

enough. And the bigger question is, will the ice continue to

exist at all?

In my lifetime, we've lost about two-thirds of the summer sea ice in the Arctic.

And it's likely that in the next 30 years we're going to end

up with an ice-free Arctic in the summer. I think one of the

issues with climate change is that it's really difficult

to see. But in the case of harp seals, it's really quite

simple.

If we lose the sea ice in the Arctic, we lose the harp seals.

For harp seals, their future, it has to be said, appears

uncertain. But what about the most famous face of climate

change, the polar bear?

Can this keenly intelligent animal adapt to a rapidly changing world?

As the summer sea ice melts away, many

polar bears are forced to head for dry land.

Some swim up to 400 miles to get there.

This is Wrangell, a remote island in Arctic Russia.

Wrangell is a unique place. Bears are part of this

landscape. It's not suitable for all of people. If I'm a

ranger, I like this life.

Without the sea ice, the hungry bears cannot hunt seals and

feed on their calorie-rich flesh, but find other sources of

food, including human food supplies.

This is an invention against polar bears.

I need to be prepared against their invasions.

Each summer, Gennady is joined by polar bear

expert Dr. Erik Reger. We need to cross that ridge.

Erik wants to find out just how many bears are ending up here.

In 20 years of studying polar bears, I've never been

anywhere like Wrangell Island. The density of bears is

unlike anything I've ever seen before. This past two years,

we've seen about 500 bears. My sense is that's just a

fraction of how many are here.

But with so many hungry animals in one place, is there enough food to go round?

Gennady, if you can keep an eye out for us, please, like up

on the hill or just wherever you got a good view. All right,

thank you.

This is a hairtrap, so bears like anything that smells

strong, and so this has a little bit of spoiled cheese,

milk, and fish in it. So the goal here is to get a polar

bear to come in and put its hand or its head inside this

box, and when that happens, these little wire brushes will

pull out a few pieces of hair that we can use for scientific

analyses. You can learn a lot about polar bears just from a

piece of their hair. We can figure out which individual it

is, or you can get information on what

they're eating. There we go, hair collected.

Eric's molecular studies of the polar bear's hair show that

the bears on Wrangel appear to be finding enough food. But

with more and more bears coming here, will there still be enough food to go round?

One of the main things we expect to happen with sea ice loss

is changes in the movements and the distribution of polar

bears. So polar bears are going to appear in places they

never were before, and they're going to disappear from

places that they were.

Some coastal towns in Siberia have been overrun with up to 50 bears at a time.

They're desperate to eat whatever they can. And in the city

of Norilsk, one female was found an incredible 250 miles

away from the coast.

Lost and starving, she was eventually rescued.

But many are not so lucky.

They are intelligent animals, but there's simply no food on

land that could compare to the seals that the bears eat on

the sea ice.

A future without polar bears would be very sad, but the sea

ice is not just essential for animals. It's a lifeline for

many of the four million people who call the Arctic their home.

People here call themselves Inuit.

Alekasiak Perry lives in Kanak on Greenland's west

coast, the most northern Inuit town in the world.

For centuries, life here has depended on the sea ice.

The dogs are the safest way to travel on the sea ice.

Without the dogs, our ancestors would have never survived.

Not only are dog sleds a way to reach neighbouring

communities, which can be over 100 miles away, but in a land

where no crops can grow, traveling over the sea ice is a

vital route to food, fur and livelihood. We rely on the sea

ice to hunt the seals, to make a living.

The way of hunting is who we are and where we come from.

But the dwindling of the sea ice is making this way of

life not only difficult, but increasingly dangerous.

This year, the sea ice has a lot of waterfalls, and

it's breaking off quite fast.

We trust our dogs.

Somehow we know when they are on the thin ice.

So based up, we cannot travel.

Today, they must turn back.

It has become difficult to be a hunter. The sea ice has

become too dangerous to make enough money to live. For

Canach's 650 residents, the loss of sea ice is the loss

of an entire way of life, and it is creating an uncertain

future. When the sea ice is gone, it will affect everything.

If the world is changing, then we must change with

it. But with us, the change has been going very fast.

And there's a reason for this accelerating rate of change.

In the last 30 years, over 14 trillion tons of ice have

been lost from the Arctic, creating a vicious cycle of ever

-increasing temperatures.

Normally, large areas of snow and ice would act as a mirror,

reflecting up to 85% of the sun's rays back into space. But

as the ice melts, the great white mirror is being

replaced by the darkness of the ice-free ocean.

The dark ocean absorbs the sun's rays, so causing even more

ice to melt. Creating a feedback loop that contributes to

further warming.

Because of this, the Arctic is now warming more

than twice as fast as the Earth as a whole.

That has far-reaching consequences not just for the Arctic

Ocean, but for the vast frozen lands that surround it. The

tundra.

In summer, the open tundra provides refuge for great concentrations of life.

But today, its thick surface soil, that has been deeply

frozen for thousands of years, is thawing. And the pooling

water is creating millions of new lakes.

Here in Alaska, we've seen a 40% increase in the lake area since the 80s.

Professor Katie Walter-Antony has worked across Alaska and

Siberia, studying their lakes. She is interested not so much

in the lakes themselves, but in what is seeping out of them.

We are seeing a bright spot in the satellite image that we

suspect is gas bubbling.

To identify the gas in these bubbles, Katie must collect

some of it. I'm surrounded by tiny bubbles that are rising.

Methane appears to be the dominant gas.

Methane is produced by the decaying remains of prehistoric

plants and animals. As the frozen soil beneath the lake

starts to thaw, it releases stores of this potent greenhouse

gas, which is up to 30 times more effective than carbon

dioxide when it comes to trapping heat in the atmosphere and

accelerating global warming. 45 parts per million for these

tiny bubbles rising higher and higher. Now it's going above

70. This is a huge amount of methane. It could be a mega

-seap.

We are discovering more and more of these methane mega

-seaps. It's streaming out and entering into the atmosphere.

Methane can be seen escaping from lakes,

but it also rises from the land wherever the frozen

soil, known as the permafrost, begins to thaw.

And the arctic tundra is thawing and collapsing at an

unprecedented rate. It's concerning because permafrost, or

frozen ground, occupies about a quarter of the northern

hemisphere land surface. As permafrost thaws, even a small

fraction of that trapped methane escapes.

It will accelerate climate warming, and you cannot reverse it.

It's clear that in the Arctic, changes to permafrost on

the land and floating ice on the sea will have far-reaching

consequences to the planet as a whole. And there is

nowhere better to see the extent of these global changes

than from space.

All of my life I've thought about how this would feel to

gaze back on the planet with my own eyes. NASA scientist

Jessica Mir has spent six months in orbit. From the space

station, you have the planet spinning beneath you, and

you're passing over it at 17,500 miles per hour. We are

going around the entire planet every 90 minutes. So you can

begin to see larger scale phenomena in ways that you just

can't experience on the ground. And we can see the change in

these systems over time. We cannot deny that we are having

an incredible effect on the fate of our planet. And the

effect that we have as humans on our planet, right there

actually, I'm looking down at several fires. I'm not sure

where those are. Let's take a quick peek.

So right now we're flying over Europe and I can see some fires over in that direction.

And that is of course something that we have to

contend more and more with as our climate changes.

As the Arctic warms, wildfires are not only getting more

intense, but they're breaking out in parts of the Northern

Hemisphere where they have never occurred before.

Some scientists believe that unusually warm air rising in

the Arctic is disturbing high-altitude wind currents like

the polar jet stream. Once disturbed, the jet stream

produces hotter and drier conditions much further south.

All of these factors that contribute to wildfires, the

temperature, the soil moisture, the presence of trees and

shrubs and other fuel, have either strong direct or indirect ties to climate change.

A warming Arctic may not only be responsible for the outbreak of wildfires,

but it may also be leading to extreme weather

conditions across the whole of the Northern Hemisphere.

I've always cared so much about the environment and known

that we all need to do our part in protecting it. But after

seeing this view with my own eyes, after seeing all of those

ecosystems from up here, it really makes it resonate even

more loudly.

Outside the Arctic, there's another frozen realm that

stretches across the world's continents, a high mountain.

Home to an extraordinary array of species.

But here, too, there's a problem.

Across the world, mountain glaciers, which have existed for

tens of thousands of years, are shrinking and vanishing.

By the end of this century, some ranges may have no ice

remaining at all. And this will affect not just animals, but

people, too.

Ice lost from the mountain glaciers, from the great ranges

of the world, have a huge consequence for the populations

downstream. And that consequence is their water supply.

Glaciers in the Himalayas are the source of ten of the

largest rivers in Asia, which together provide reliable

fresh water for around a billion people downstream.

If the glaciers disappear, so, too, will the water they supply.

We know that these glaciers are losing about half a metre of

ice a year. What we don't know is how much ice is left. So,

if we know how many metres of ice are left, we can work out

how long they'll last. How long this water supply will keep

going. Dr Hamish Pritchard is part of a team of scientists

who have devised a new instrument to measure ice. They

measure one of the largest Himalayan glaciers. What we're

putting together here is a long frame structure, and it's

designed to hang underneath a helicopter. We're going to put

a radar on it, and the radar will send out radio waves and

then bounce back off the bottom of the glacier, and we'll be

able to measure how thick the ice is. Once his team know how

thick the ice is, they can start to work out how long it will last.

Yeah, today was the moment we were just waiting for it to

get lifted up for the first time. We're hoping it's going to

be nice, steady, stable, nice, easy lift off, but we're about to find out.

Line is clear.

There's a lot of lifting.

Okay, Mike, we must north of me, north of H.E.V. to the

Khunjung area. Hi, Dr Hamish here. How's it flying? Yeah,

with the wind picks up, it's a little more squirrely, but no

problems otherwise. Yeah, it might want to go up a bit more.

We're going a little bit of height there. Yeah, no

problem. Yeah, we'll fly up the net towards Everest.

After hours of scanning, the projection for

this particular glacier is finally revealed.

Yeah, that's pretty nice and clear. I can see exactly

how thick that ice is. That's about 150 meters.

So at the current rate of melting, this section would last

maybe two to three hundred years. But we know that the melt

rates are increasing.

And this is one of the biggest glaciers, so there are many,

many glaciers which are much smaller than this. Much thinner

ice. And they're going to be disappearing much, much earlier than that.

Water is already scarce in parts of Asia. And as glacial

water supplies dry up, there will be even less to go round.

So what happens if these glaciers disappear?

Is that in dry summers, the rivers dry up. Tensions rise,

especially between nations as they share water across

borders.

So one of the big risks of losing this ice is that it raises the risk of conflict.

And that's a frightening prospect. If I have a one-year-old

son, children born at the same time as him will see this

happen.

We need to act now to turn those trajectories round.

There's no doubt that large tracts of our frozen wilderness

are undergoing dramatic changes. But what about the largest

body of ice of all? Antarctica.

We have already seen how even here, animals live in the ice.

The living around the fringes are starting to be affected by

climate change, including chinstrap penguins.

But for another penguin, the Adelie, the consequences are even more extreme.

I arrived here for the first time in 1974.

This part of the world was just

incomprehensibly wild. It was filled with life.

Antarctica absolutely captured me.

Professor Bill Frazer has dedicated his entire

45-year career to studying the Adelie penguin.

What really fascinated me was the incredible hardiness of

these penguins. Feisty, determined, beautiful little animal.

But this environment is changing.

In the last 45 years, the tremendous warming that has

occurred has had an incredible impact. The changes have been

very rapid, more rapid than anyone anticipated.

Bill has witnessed firsthand how these changes have affected

one of the largest colonies of Adelies on the western side

of the Antarctic Peninsula. Four decades ago, this area

contained 20,000 adults. Currently, we only have somewhere

in the order of 400,000 adults. We have 100 breeding pairs.

One of the issues that Adelies are clearly experiencing

right now is just the increase in rainfall.

Adelies are a creature of the high Antarctic. They evolve in

a dry, cold polar system. They simply cannot tolerate being

continuously wet.

The chicks are soaking.

The rain is penetrating their down, breaking

down their ability to insulate themselves.

That's why you see they're shivering, because they're just

trying to maintain their body temperature and they can't.

Sad.

This tiny chick at this point has zero chances of surviving.

They can't even react to the presence of a predator.

We are standing, looking at climate change, actually

killing off these Adelie penguins, one at a time.

Before he leaves Antarctica for the last time, Bill is

visiting an island that was once an Adelie paradise.

When we used to walk onto this island, you could

immediately hear the Adelies. They were everywhere.

In 1974, the populations here were somewhere in the order of

a thousand breeding pairs. All that remains are these little

pebbles scattered throughout the area, stones that were used

in former nest sites. The pebbles are still visible, they're

very abundant, but the birds are gone. This is where

we recorded the first island-wide extinction of Adelie

penguins.

And now the silence that exists here is pretty overbearing.

There's no words that can really describe what I'm feeling at the moment.

We're working with canaries in the coal mine. The Adelie

penguins are, without a doubt, indicator species that are

telling us that the globe is changing, the globe is getting

warmer, it's happening, and we need to do something about

it.

The disappearance of Adelie penguins along the Antarctic

Peninsula is just one example of how record warming

temperatures are affecting life here.

But warming temperatures are also affecting the very

coastline itself. With serious implications for global sea

levels...

Across the glaciological community, we've identified that

sea level rise from Antarctica is the most pressing question

for the next 50 to 100 years. And we as a collaborative

group have come together to try and understand it, and

governments have come together to try and understand it

because it's important. Professor Sridhar Anandakrishnan has

been working in the polar regions for over three decades.

He's part of a team of scientists undertaking the largest

Antarctic expedition for more than 70 years. Their

destination is a remote part of western Antarctica called

the Thwaites Ice Shelf.

Without getting out on the ice, you can't measure things underneath the ice.

Those kinds of things can't be done from space. They can't

be done by drones or aircraft flying over it. You actually

have to go and put your instruments on the ice.

The interior of Antarctica is covered in a giant sheet of

ice, which for millennia has been slowly flowing to the

coast.

But because it's so cold here, rather than carve into the

sea, the ice continues to flow out into the ocean, forming a

floating platform known as an ice shelf.

As an ice shelf grows, it begins to act as a dam, preventing

more of the ice sheet behind it from slipping into the sea.

And the Thwaites Ice Shelf holds back a body of ice the size of Florida.

But scientists are concerned that the ice shelf itself is

now at risk of melting. We're going down through 600 meters

of ice. Once we drill the hole, I'm going to put the explosive charge down.

Small seismic surveys... Okay, firing the hole.

...help establish exactly where to sink their robotic

underwater probe, which the team hope will record the

temperature of the seawater directly beneath the ice shelf.

Okay, Andy, ready to descend. Try to go a little slower.

Okay. Coming up on 75 meters. 75 meters now.

425 meters. We've arrived at the ice-ocean interface.

Early results are not encouraging. Have we noticed a huge

change in the temperature? Uh, yeah. It is warm water. Can

you see it melt? Like, what's going on there? Because of

climate change, warmer seas directly beneath the ice shelf

are melting it from below. So it's no longer a question of

if this giant dam will disappear, but when. When the vast

ice sheet behind it spills into the ocean, it could have

catastrophic consequences for global sea levels over the

coming centuries.

The amount of water that Antarctica contains

that could go into the ocean is so huge.

This is a global problem. The oceans are all connected

together, so as soon as a glacier puts water into the ocean,

it rises all over the world.

If sea levels rise as predicted, by the year 2050, 150

million people could be displaced from coastal areas.

And by 2070, cities including Miami, New York, Shanghai

and Mumbai will be at risk of serious flooding.

How much water will Antarctica contribute to sea level rise?

The biggest wild cardinal of that is how we as humans affect

climate.

Recently, at COP26, 120 nations came together in

an effort to limit global warming to 1.5 degrees.

While a 1.5 degree rise will still bring significant

changes with it, to some extent, it will be a challenge. To

understand any chance of saving what remains of our

frozen planet and saving ourselves from the devastating

consequences of its loss, we must stick to this commitment

and honor it no matter how challenging it might be. We know

that climate change is happening. We know the main driver of

climate change is human activities, it's human emissions. As

a whole human species, we are not recognizing the impact

that we're having and the fact that we do need to do

something. But the important thing is that I believe all

these processes are reversible. If everybody can make the

effort of doing just one thing, reducing their carbon

footprint. Consume less, think about what we need, what we

really want. Think more sensibly about the journeys we take,

about the food we eat, how that's produced. Figure out a

lifestyle that is sustainable.

And we're right at the point where we can generate all the

power that we need from renewable sources like solar and

wind. To do that, you need to really transform society as

a whole. We can speak to our representatives to try and

reconsider energy policies. If enough of us are educated

about the effects of carbon in the atmosphere, even the most

poorly educated politician will respond to what their

citizenry wants. The awareness and the concern is greater

now than it ever has been. So that gives us some hope. It

won't be easy, but it's doable. If you can do something

about it, then do it. Instead of just thinking about

it, if you can do something about it, then do it.

We can do it. It's within our power to do it. We can do it. We must do it.

Then there will be a future for the planet.

We can do it. We can

do it.