01x08 - When America Flooded

[bunniefuu]

[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


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 b*mb.

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 sh**t 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 k*lling
of a mammoth is a rare feat.

So there is good
reason to celebrate.

There are still only about


but they are skilled
hunters...

...and, as a group, are able
to k*ll 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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