All language subtitles for A.Perfect.Planet.S01E01.Volcano.2160p.BluRay.REMUX.HEVC.DTS-HD.MA.TrueHD.7.1.Atmos (1)

A Perfect Planet.

There is only one planet
in the universe, as far as we know,

where there is life.

The Earth.

Our home.

The perfect planet.

Life here is only possible

because of a unique balance
of natural forces.

Energy from the sun
powers the living world.

Weather systems transport fresh water
around the globe.

And powerful ocean currents
circulate life's essential nutrients.

This series will reveal

how these global forces
have worked together

to create our planet's
fragile life-support system.

One of these forces is so important

that life would never have even started
without it.

Across the surface of our planet,

there are over 1,500 active volcanoes.

This is the most active -
Kilauea in Hawaii.

Here, magma - liquid rock
from the planet's hot interior -

bursts out through fractures
in the Earth's crust.

And it's been flowing for months.

Nothing can stand in the lava's way.

Volcanoes are certainly destructive,

but without these powerful
underground forces,

there would be no breathable atmosphere.

No oceans.

No land.

No life.

We can't control volcanoes,

but they're vital for all living things
on Planet Earth.

This is Cl Doinyo Lengai in Tanzania.

It's one of Africa's
most active volcanoes,

and has erupted over 15 times
in the last hundred years.

On its northern flank lies Lake Natron,

400 square miles in extent,

and one of the world's most corrosive
bodies of water.

The water wells up from deep below,

carrying such a concentration of chemicals
that it can burn skin.

But one animal thrives here.

Volcano birds.

Nearly two million lesser flamingos
live in East Africa

and all of them come here to breed.

But they can only nest here
when the lake's level drops so far

that in the centre its bed is exposed.

And that rare moment is now.

How they know when the conditions
are right is a mystery.

But some have flown
thousands of miles to be here.

The flamingos head
for the middle of the lake,

where the intense evaporation
has created islands of salt.

It's here that
the birds build their nests,

over three miles from the lake's edge

and safe from land predators,
which are unable to cross

the surrounding moat of caustic soda.

The single egg
is laid on a mount of hardened salt

built by the adults,

its height an insurance against

a sudden rise in water level...

which often happens on Lake Natron.

As the centre dries and enlarges,

more and more flamingos arrive
to nest on it.

In good years, such as now,

as many as half a million pairs
breed here.

After 28 days of incubation,

a chick emerges into Natron's harsh glare.

Here, temperatures can rise
to 55 degrees Celsius.

Mother's wing, however,
can serve as a sun-shield.

The chick is fed a rich liquid

made of the lake's barely digested algae

and traces of its parent's blood.

After a few days, the chick
is strong enough to stretch its legs.

It then joins a growing creche
made up of chicks of different ages.

Soon, the need for fresh water
will force the infant birds

to trek to springs on the lake's edge...

a journey they have to make on foot,
as their flight feathers

have yet to develop.

Every day, the adults fly to these springs
to feed.

Here, on the lake's margins,
they collect algae that flourish

in the volcanic water -
vital food for the flamingos.

It's the algae that turn
the flamingos' feathers pink.

It even colours their eyes.

The adults spend most of their day
at the springs,

and now their chicks
are going to join them there.

No-one wants to get left behind.

It's a three-mile march
over razor-sharp flakes of soda

and sticky, caustic mud...

a life-threatening trial,
especially for the youngest chicks.

The groups merge into one giant creche.

For some, the challenges
are just too great.

Exhaustion overcomes the weakest.

And now there is yet another threat.

Marabou storks.

They have long legs like a flamingo,

but a beak like a Roman sword.

And they are patient,
waiting for an easy target.

Their very presence creates panic
among the chicks.

The smallest avoid
being trampled underfoot

by travelling on the outside of the group.

But that exposes them to attack.

Their only defence is to run.

But you have little chance

when you're barely ankle-high
to your pursuer.

Stragglers will almost certainly be taken.

But there comes a point
when every stork has had its fill.

This little chick is very lucky.

At last, the youngsters reach
the freshwater springs

at the lake's margin
to rejoin their parents.

Almost unbelievably,
each chick has a unique call

that its parent can recognise.

It's not just lesser flamingos
that depend on volcanoes.

Ultimately, so do all living things.

Over 80% of the Earth's surface

is the result of magma
bursting up from the molten interior.

The process started four billion years ago

and it still continues today.

When lava cools, it solidifies into rock

and eventually weathers
into land that can support life.

All the Galépagos Islands
in the Pacific are volcanic,

and Fernandina is the youngest of them...

and still growing.

At its centre, a volcanic crater
four miles wide...

and over 800 metres deep.

It seems dormant, but it was erupting
only two weeks ago.

Even so, there are some who depend
on the heat from this volcano.

A female land iguana, heavy with eggs,
approaches the crater's rim.

It took her ten days to climb up here,

but the toughest part of her journey
is still ahead.

She's going to descend
into the crater itself.

Frequent tremors
make the crater walls unstable.

More people have travelled in space

than have visited the bottom
of Fernandina's crater.

But instinct drives her on.

The warm volcanic ash on the crater floor

has the perfect temperature
for incubating her eggs.

But there are no clear paths down.

Any made last year
have been destroyed by rockfalls.

The slope is steep and unstable.

Tumbling rocks
quickly become an avalanche.

With the boulders falling down
away from her,

she's not in immediate danger.

But behind her, higher up,

two other females
have also started the descent.

And now she is in the firing line.

She's safe.

Others before her haven't been so lucky.

But she's undeterred.

At last, after an eight-hour descent,

she reaches the crater floor.

Now she must find a suitable place
to dig her nest.

The best sites are already taken.

And nesting females are very aggressive.

A nodding head means keep away.

Push off!

Ignored warnings are met with force.

But she's come a long way,
and she's not going to give up now.

She, too, starts to dig a hole
in which to lay her eggs.

That done, she will head back,

leaving the volcano to provide
the warmth her eggs need

if they are to hatch.

Sometimes, of course, the volcano erupts

and destroys not only eggs,
but many nesting adults.

But for the iguanas, the benefits
of nesting in the crater are so great

that it's worth all the risks.

Volcanic islands make up just 5%
of the planet's land,

but they're home
to nearly 20% of its species.

Animals often evolve very swiftly
on islands,

cut off from their mainland relatives

and faced with the challenges
of isolation.

This is Wolf, an extinct volcano

and one of the most remote islands
of the Galépagos,

800 miles from
the nearest large landmass

and over a million years old.

A finch.

A female.

Its ancestors doubtless were blown here
by storms many centuries ago.

Like most finches, they feed on seeds,
nectar and insects.

But there's little food of any kind
on Wolf.

And since they aren't strong enough fliers
to leave the island,

they've had to find food
from a very unusual source.

They depend on another
of the island's inhabitants.

Nazca boobies.

Every day, these seabirds commute

between the island and their
fishing grounds out in the open ocean.

Each time a pair meet,
they renew their bond...

and then catch up with the neighbours.

Now is the time...

to hop into action.

Blood.

They are vampire finches.

These little birds have become
one of the world's newest species.

She cuts the quill
of a large flight feather,

and the blood flows.

The sight of it attracts the attention
of others.

Blood is very nutritious -
worth fighting for.

So, with this never-ending supply
of food,

the vampire finches
can flourish on an island

where otherwise they could not survive.

Why the boobies don't object,
nobody knows.

Perhaps the finches' behaviour started

when they helped the boobies
to remove parasites from their plumage.

Maybe the boobies
think that the little vampires

are still providing a service.

Who can tell?

Volcanic islands don't last forever.

Changes deep in the Earth's crust
bring their eruptions to an end,

and the forces of erosion
then begin to wear them down.

But the coral around them
continues to grow,

sea levels change,
and eventually all that is left

is a ring-shaped island of coral rock
surrounding a lagoon.

An atoll.

There are hundreds of atolls
in tropical seas,

all remnants of vanished volcanoes.

This is one of the largest
and most pristine -

Aldabra, in the Indian Ocean.

20 million years ago, it was an island

with a volcanic crater in its centre.

Now it's an atoll.

Mangroves took root
and seabirds came to nest.

One land animal in particular...

reached here before man.

A giant tortoise.

These creatures can float

and live without food or fresh water
for long periods of time.

This isolated atoll is the perfect refuge.

Their only enemy is the sun.

Without shade, a tortoise risks
being boiled in his shell.

So, after feeding
in the cool of the morning,

and before the sun
becomes too crushingly hot,

they have to find cover.

All of them.

There is very little vegetation,

but caves in the coral rock

can provide the shade
they so badly need.

He's nearly there.

All that is left
is a white-knuckle ride to the bottom.

And he's in.

Thousands of others
are still out in the sun.

This tree could shade
a couple of hundred, if they pack tight.

It's bumper-to-bumper parking.

Within an hour or so,
all must find shade of some sort

if they're to survive.

Safe.

But the future for Aldabra's tortoises
is far from certain.

The climate is changing,
sea levels are rising,

and Aldabra's tortoises
may soon have to find a new refuge...

or drown.

In some places, volcanoes erupt
not in the ocean,

but in the very middle of a continent.

North America, and in its very heart,

a volcanic hot spot - Yellowstone.

The last major eruption here

came to an end about 650,000 years ago,

but this volcano is only sleeping.

Not far below ground,
there is still magma.

And that heats the groundwater
to boiling point.

Geysers.

Some spout boiling water and steam
to heights of 9O metres or so.

Elsewhere, the scalding waters
liquefy the ground sediments,

creating pots of boiling mud.

And this underground heating
has proved a lifeline for some.

River otters.

They need a constant supply of food
if they're to keep warm

in these freezing temperatures.

And this close-knit family
know exactly where to find it.

The springs are so hot

that the rivers never freeze,
even in the coldest winters...

so the otter family can fish
the year round.

Trouble.

This coyote knows
that in the middle of winter

a thermal river means otters,

and otters mean fish.

The question is...
how to steal their catch?

Perhaps the thing to do
is to pretend you're not interested...

and hope that they wander close enough
for a snatch-and-run raid.

It seems the cool-under-fire otters

can outwit the not-so-wily coyote.

Many animals benefit
from the volcanic heat

coming up from below.

And we do as well,
but not nearly as much as we could.

The volcanic heat could provide us
with much of the energy that we need,

and then we could stop burning gas
and coal

that is now changing the climate
worldwide.

Deep in the Earth's crust,

below both the oceans
and the continents,

there are lines of weakness
along which rises liquid rock.

The Kamchatka Peninsula
in the north-west Pacific

lies along one of them.

There are only a thousand known geysers
in the world,

and many of them are here
in this isolated valley.

Steam from superheated water
fills the air.

But the danger from the scalding pools
does little to deter.

Kamchatka's most famous residents.

In May, when the rest of Kamchatka
is still covered by snow,

this valley is free of it,

and bears, having just woken up
from their winter sleep, know that.

The grass is fertilised
by mineral-rich water

spraying from the geysers...

much-needed forage for a large male
bear that hasn't eaten for several months.

And he's not the only one.

The bears haven't seen one another
for seven months,

since the start of winter.

And it seems that right now
they would prefer to keep it that way.

Nothing should come between a bear
and his first meal of the year.

And in one place,
Kamchatka's underground forces

provide its bears
with even more nutritious meals.

Kurile Lake lies within the crater
of an immense volcano

that long ago produced one of the greatest
eruptions in the planet's history.

The lake is still circled
by active vents...

and mineral-rich ash
from their regular eruptions

has made these waters
particularly fertile.

Millions of salmon come here
from the Pacific Ocean

in order to spawn in these fertile waters,

which will provide their newly hatched
young with abundant food...

so grass soon ceases to be top
of the menu for Kamchatka's bears.

By the time spring has turned to summer,

Kurile Lake contains
the most dense assembly of bears

to be found anywhere on Earth...

all hungry for salmon.

But this early in the season,
the fish are still strong and swift.

Nothing seems to work.

But one old bear knows that right now

there is an easier meal to be had.

He remembers that
if he paddles out into the lake,

away from the shoals
of newly arrived salmon,

there's food that doesn't need chasing.

Some of the first fish to arrive
have died,

and their bodies
can be easily collected...

from the bottom of the lake.

Diving for them at leisure
doesn't use many calories.

And he can take his time.

A couple of weeks later,
the salmon are beginning to spawn

and are less wary.

Now it's worth running.

The fish are so abundant...

that there is plenty for all...

even those with no previous experience.

There are now so many fish,

it's difficult to know which one to chase.

In a single day, a bear can consume

100,000 calories,

50 times more than
the average human being does.

And one part is particularly delicious.

Caviar.

80 calories in every mouthful.

By supporting huge concentrations
of salmon,

mineral ash from Kurile Lake's volcanoes

has made life surprisingly easy
for these bears.

Our planet depends on minerals
brought up by volcanoes

from the Earth's molten core.

A single ash cloud
can carry billions of tonnes of minerals.

And as a consequence,
the lands surrounding volcanoes

are among the world's most fertile.

Those in East Africa's Rift Valley

support the most dynamic ecosystem
on Earth.

The Serengeti.

This is the most productive
of all natural grasslands anywhere.

Every year, over a million wildebeest

assemble in this particular corner
of the Serengeti

to feed on grass specially rich
in calcium and phosphorus -

essential minerals
for the pregnant females.

In just three weeks,

half a million calves are born
on these ash-rich plains.

That's 24,000 a day,

a thousand an hour.

Calves stand up within a few minutes
of being born...

though some need a little more time
to find their feet.

But a mother won't let her calf suckle

until it's mastered a few physical skills.

Walking.

Trotting.

And running.

Wildebeest calves must run
if they're to stay alive...

for these plains also support

the greatest assembly of hunters
on the planet.

Each species has its own
special hunting technique.

But all have the same aim...

to make the most
of this brief super-abundance of life.

Only one in ten wildebeest calves

will survive to adulthood.

But that is enough to maintain

the million-strong herd of wildebeest...

and the planet's highest density
of predators.

Volcanoes fertilise the planet,

but they're the source
of something else so important

that life could not have started
without it.

The first carbon dioxide
in the Earth's atmosphere

was brought by volcanoes
from deep in the Earth's crust.

And this gas is the foundation of life.

Every plant needs it to grow,

and absorbs it from the air.

Volcanoes continue
to release carbon dioxide today,

and for the last 10,000 years

its presence in the atmosphere
has suited life perfectly.

Its greenhouse properties
have kept our planet's climate

stable and warm.

But too much carbon dioxide

would make the planet's temperature
rise to levels

that would upset the Earth's
long-established ecological balances.

Today, humanity itself
has become a new kind

of supervolcano.

Now, every year, we ourselves
release 100 times more carbon

than all the Earth's volcanoes combined.

And that has brought climate chaos.

We can't control volcanoes.

But we can limit the amount
of carbon dioxide that we produce.

And if we do that,
there will still be time

to restore the ecological balance

that once made this Earth
our perfect planet.