Original subtitles

[narrator] The story of life on Earth

[baby dinosaur croaking]

[dinosaur roaring]

has been marked

by a series of catastrophic extinction events.

Natural disasters which have threatened to wipe out

many of the creatures that call our planet home.

But after every brush with death

[roaring]

life has come back even stronger.

One of the most recent disasters

happened just 12,000 years ago

in North America.

A vast dam of ice and rock collapsed,

unleashing one of the greatest floods

the world has ever seen.

[mammoths growling]

A catastrophe so enormous,

it slammed the Northern Hemisphere back into an ice age.

-[bear growling] -[wolf whining]

In this turmoil,

even the mightiest struggled to survive.

-[wolves growling] -[mammoths roaring]

But out of the chaos

rose the most dominant species on Earth today

[grunting]

Humans.

-[dramatic music] -[birds trilling]

Northern North America

at the end of the last Ice age.

A land of glaciers, snow, and ice.

While the frozen landscapes

and endless forests may look familiar

the giant creatures that live amongst them

are anything but.

[dire wolf howling]

A dire wolf.

A whole one third bigger than the gray wolf we know today.

He’s picked up the scent of fresh blood.

[dire wolf sniffing]

♪

His nose leads him to an abandoned carcass.

Something to fill his belly.

[bear growling]

-[dire wolf whimpering] -[bear growling]

A giant short-faced bear...

[growling]

...North America’s largest bear ever.

She is ferocious,

especially now she’s defending two new cubs.

This Mama Bear needs all the meat she can get

to help them all survive their long hibernation.

Three months later,

spring arrives across North America.

It’s coming earlier with each passing year.

The Ice Age that has gripped the Earth

for tens of thousands of years is losing its hold.

As the snow and ice melt away,

the wonderful creatures of these dense forests

begin to stir.

[bird cawing]

The lush new growth has drawn in other animals...

[mammoths groaning]

...like these mammoths.

Outside her den,

Mama Bear prepares for her first hunt of the spring.

Her cubs want to tag along,

but they are still too small to leave the den.

Before she hunts,

she needs to do something

she’s been dreaming of all winter.

[playful music]

Oh yeah, that’s the spot.

Yet, this is much more than back-scratching.

She’s marking her territory by spreading her unique scent,

vital for warning off other bears

while her cubs are home alone.

[bear growling]

And now, onto the hunt.

She picks up the distinctive smell of prey.

After months of hibernation,

she’s lost a third of her body weight

and is ravenous.

A shelter, which can mean only one thing...

humans.

Only a handful of humans roam these lands.

And they’re smart enough not to mess with a giant bear.

[bear sniffling]

[bear growling]

[fast-paced music]

[bear growling]

[human grunting]

This Mama Bear is still too heavy

to climb a tree, even though she’s half starved.

Our giant short-faced bear, however,

is dwarfed by a much greater force.

One that looms over her territory.

Only a few miles from her den, the Laurentide Ice Sheet.

Formed during an ice age that gripped the Earth

for tens of thousands of years,

it covers millions of square miles

of the North American continent,

north of the Great Lakes.

It is one of the largest expanses of ice

the world has seen in hundreds of millions of years.

But now, as temperatures rise,

this massive ice sheet is melting.

Downstream, the meltwater is swelling rivers.

[bear grumbling]

[stag-moose huffing]

A stag-moose.

Our Mama Bear knows there’ll be easier prey.

[stag-moose grunting]

[stag-moose grunting]

A stag-moose is a formidable foe With six-foot antlers.

But this one is old and past his prime.

And he is unaware he’s being tracked

[dire wolf growling]

A dire wolf.

Still, no threat to this old boy.

Except this wolf brought friends.

After a desperate winter, they have formed a super pack.

Now, even the giant moose is in trouble.

[dire wolves barking]

It is the end of the last Ice Age 12,000 years ago

and still, most of what will become Canada

is covered in an ancient ice sheet.

However, this is beginning to melt,

swelling all the local rivers.

In a valley below,

our older stag-moose has been targeted by dire wolves.

[dire wolf growling]

They have formed a super pack

and now, even powerful animals like this stag-moose are prey.

[dire wolves barking]

Few animals can outrun a pack of dire wolves for long.

[dire wolves barking]

Our stag-moose chooses deep waters, over being eaten alive.

But this river is now swollen by water from the melting ice.

And the current is too strong to fight.

[stag-moose groaning]

It was a brave attempt.

The wolves watch

to see if the stag’s body washes up

at the bottom of the falls.

Eventually, they give up.

[stag-moose huffing]

Miracles can happen

and this old timer is proof.

He has survived the falls.

[stag-moose groaning]

He’s lost an antler,

but it’s a small price to pay for cheating death.

[stag-moose roaring]

Months later, spring gives way to summer.

Our Mama Bear is now well-fed

and is taking her cubs on field trips

further and further from their den.

In the valley, there are more mammoths now

And they’ve been joined by a distant cousin...

a mastodon.

Shorter than a modern elephant, but more heavily built.

Mammoth and mastodon have roamed this continent together

for millions of years.

Yet all these creatures are living on borrowed time.

The giant ice sheet is a ticking time bomb.

As it continues to melt,

it’s doing more than just swelling rivers.

Vast quantities of water are on the move.

Trickles feed streams that turn into torrents.

Entire rivers vanish down deep holes in the ice.

But this glacial meltwater doesn’t just disappear.

Along the edge of the Laurentide Ice Sheet,

a giant lake has been building...

year by year.

Now, it covers an area

larger than all the Great Lakes combined.

23 hundred cubic miles of meltwater,

held back by dams of rock and ice.

And as the pressure builds,

these dams are about to break.

The magnificent creatures in the valleys

have no idea what’s on its way.

[dramatic music]

[rocks crumbling]

The vast Laurentide Ice Sheet that covers most of Canada

is melting and along its edges, enormous lakes have developed.

So far, they have been held back by ice dams,

but they are about to reach their breaking point.

On the wooded slopes below,

our Mama Bear has poached a fresh carcass.

But her cubs are not where she left them.

A mother’s work is never done.

[bear growling]

They are playing hooky,

lured away by a fascinating, prickly creature...

a porcupine.

With 30,000 barbed quills covering his body,

most in this forest just leave him alone.

Our naive cubs, however, are new to the neighborhood.

[cub sniffing and grunting]

[cub groaning]

-[cub crying] -[bear sniffing]

Rude.

Our Mama Bear’s jaws may be bone-crushingly powerful,

but she can also use them for delicate cub maintenance.

This little one won’t be messing with porcupines again.

[cub whimpering]

[bear growling]

After months of only their mother’s milk,

this is the cubs’ first taste of meat.

[bear grunting]

But Mama Bear senses something’s not right.

[ice cracking]

[mammoths growling]

She leads her cubs back up toward their den,

high on the hillside.

[ice creaking]

[ice crumbling]

[dramatic music]

The giant wall of ice finally breaks.

[mammoths growling]

♪

Thousands of cubic miles of glacial meltwater

tear across North America toward the Atlantic Ocean.

♪

This event, 12,000 years ago,

is one of the greatest flash floods

in the history of the planet.

♪

[soft eerie music]

Two months after the catastrophic flood,

a landscape decimated by water and ice.

Desolate, lifeless, except...

our bears have survived.

[bears growling]

Mama bear’s instinct saved her babies

by heading up to the den.

At this time of year, they should be feasting.

Instead, they are all starving.

[snuffing]

♪

[sniffling]

[sharp grunt]

Another creature that has survived the flood.

A huge male short faced bear;

but he’s not interested in mating.

He’s hunting the cubs.

[light growl]

[loud growl]

[loud growling]

[growling continues]

There is no chance to run.

Our giant Mama Bear has met her match.

[snarling]

[narrator] A gigantic flood containing thousands

of cubic miles of meltwater

has stripped this landscape bare.

And now the few animals left

face a bleak struggle for survival.

For our mama bear and her cubs,

their worst nightmare has just tracked them down.

A hungry male.

[loud growling]

[dramatic music]

[growling]

He is larger.

But this mom will fight to the death

to defend her young.

[growling]

The winner of this battle will decide the cub’s fate.

[whimpering]

[loud growling]

[loud growling]

[whimpering]

[loud growling]

[loud growling]

A truce... for now.

The male bear has the cub’s scent.

[snarling]

This is not over.

♪

[light splashing]

[tense music]

[narrator] Days later, tragedy.

Our mama bear did eventually lose

one of her cubs to the male.

[mama bear grunts]

Her whole world has been turned upside down since the flood.

[mama bear grunts]

But the devastation is far wider.

The deluge has swept across the Great Lakes

and followed the St. Lawrence river,

leaving a path of destruction 500 miles long.

And dumping 2,300 cubic miles

of cold freshwater into the Atlantic.

♪

The massive outpouring of water

changed the movement of the ocean...

leading to the collapse of the North Atlantic current.

Usually it transports as much warm water northwards

as 100 Amazon rivers.

Now this vast source of thermal energy

has been interrupted by the megaflood

sending the northern hemisphere back into the ice age.

♪

[dramatic music]

Most animals here are tough and resilient

and have seen cold periods come and go.

♪

Large animals like mammoths are able to move away

in a desperate search for something to eat.

But these bears don’t migrate.

Our heartbroken mama bear has found a new den

to escape being discovered by the male bear.

In this cold weather, they should start to hibernate.

But she doesn’t have enough milk

to sustain her cub to another winter.

[mama bear groans]

She must find more food.

♪

♪

She’s alone in this frozen wilderness.

♪

She smells something familiar.

Humans.

Several families drawn together.

In these extreme conditions,

they stand a better chance of survival as a group.

And it’s paid off, hunting caribou.

They even have enough to share.

♪

[bear grunting]

It’s dangerous approaching this many humans.

She is desperate, but this is a fight she could lose.

[roaring]

[narrator] Following the collapse of ocean currents,

Ice Age rules have returned to North America.

The speed of this climate change has been catastrophic

for some of the animals here.

Our Mama Bear has been unable to prepare for hibernation

and now has to leave her cave and her cub

in a desperate search for food.

Her nose leads her to a human encampment

but stealing from humans carries enormous danger.

[humans yelling]

[growling]

She is huge but they are many, and equally desperate.

[loud snarling]

[men yelling]

She makes her escape

[owl hooting]

[light grunt]

She retreats after scavenging some of the humans’ caribou.

It’s not much,

but it should sustain her cub for now.

[groans]

The price, however, has been high.

There is a spear deep in her side.

She risked it all for her cub, but soon he will be all alone.

The Mama Bear’s strength and devotion was enormous

but it was no match for this climate shock.

♪

The disruption of the North Atlantic Current

and rapid cooling in North America

has far reaching implications.

For 1,000 years, ice age conditions return,

with fleeting summers,

and winters that are much longer, and colder.

For all the creatures here, it’s a profound climate shock.

But, in an ever changing world,

eventually, the warm Atlantic currents recover.

And temperatures shoot back up,

even more quickly than they dropped.

At one point, average temperatures rise

by 18 degrees in just a few decades.

The impact of violent swings in climate

are too much for many larger animals...

...like the giant short-faced bears.

And yet, it is the making

of one particular mammal species...

...humans.

[birds chirping]

Life has rebounded...

... but is still racing to catch up

with the increasing temperatures.

Some familiar creatures are thriving...

... including elk, caribou and musk ox.

But few of the ice age giants remain.

There were once tens of thousands of mastodons

in this part of North America.

Now this tired old male is the last of his kind...

forever in search of a mate.

[mastodon snarls]

Today, at least, he has found some company.

A mother mammoth with her seven-year-old calf.

The iconic species

is also teetering on the edge of extinction.

[snarling]

But these majestic creatures

face a more immediate challenge...

Hunters.

[low grunting]

[roars]

Once, these powerful animals had little to fear from people.

Now, things have changed.

[hunters yelping]

While the mastodon may be old,

he can still leave the humans in the dust.

But these hunters aren’t trying to catching up...

...they are herding them straight into a trap.

[mastodons grunting]

[man grunts]

[narrator] A thousand years after the Great Flood...

The imperious giants of the ice age,

like mastodon and mammoths,

once had little to fear from humans.

Now, humans have grouped together

to become ruthless hunters.

They have become the apex predator.

These giants are being driven exactly

to where the humans want them.

The hunters have spears.

These are heavy, and tipped with razor-sharp flint,

capable of piercing thick hide.

[loud yelling]

[mammoth growling]

[man grunts]

[grunts]

[mammoth growls in pain]

[grunting]

[narrator] The spear has pierced a vital organ

of this poor mother mammoth.

[groans]

[distant growling]

♪

[mammoth groans]

By nightfall, it’s all over.

The old mastodon has survived yet again.

But he will remain a tempting target for humans...

... and will be lucky to make it through the fall.

♪

For the humans, the killing of a mammoth is a rare feat.

So there is good reason to celebrate.

There are still only about 10,000 humans in North America,

but they are skilled hunters...

...and, as a group, are able to kill any animal they choose.

This is what finishes off the last of the Ice Age giants.

It is the price of human success.

[light music]

[narrator] 12,000 years have passed...

since the great American flood

led to the collapse of the North Atlantic Current.

Today, there are signs it may happen again.

Our warming planet is now melting

the Greenland Ice sheet in the Arctic ...

and vast amounts of icy freshwater

are pouring into the North Atlantic every year.

We now know from the great ice age flood,

the profound impact on climate this could have.

♪

Extinction events from Earth’s past

can teach us a great deal about our future...

... Whether it’s toxic oceans...

...rising carbon dioxide...

...or falling asteroids...

...our beautiful planet can become a harsh home.

♪

But as we’ve seen, life always adapts...

and comes back stronger.

♪

♪

Now, once again, the Earth is changing.

Unlike the catastrophes of the past, however...

there is one important difference:

This time, one species has control

over the causes of the change.

♪ Trees of green ♪

♪ Red roses, too ♪

♪ I watched them bloom for me and you ♪

♪ And I think to myself ♪

♪ What a wonderful world ♪

♪ Yes, I think to myself ♪

♪ What a wonderful world ♪

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