Planet Earth: a place of constant
change at the hands of powerful beings:
us.
Hundreds of thousands
of miles into space
and deep beneath the earth's surface
we've created an amazing world,
shaping continents,
creating ingenious monuments
and transforming landscapes.
But the only way to fully
understand the scale of our influence
is to witness the world without it.
If we suddenly disappeared, what
would happen to our highways,
cities,
rivers,
our greatest monuments?
Enter a desolate world;
a world without humans.
One minute from now, every single
person on earth will disappear.
It doesn't matter how
or that it's far fetched.
What's important is what
will happen when we're gone.
Of the billions of people in the world,
half live in cities.
Farms and pastures cover
a third of all dry land.
We've dammed and diverted
half the world's major rivers.
500 million cars clog
the roads and highways.
We've affected the air,
the sea
and the land.
But have we changed the earth forever?
If we vanished, could
the planet recover,
even erase all evidence
that we ever existed?
Friday, June 13th.
In Berlin, it's 1:30 in the afternoon.
Across the Atlantic, stockbrokers
get an early start on Wall Street.
Las Vegas is anything but sleeping,
and in Tokyo, parents
tuck their kids into bed.
Then suddenly, the human
race comes to an end.
Every single person in every
corner of the world vanishes.
Cities transform into ghost towns.
Laughter lingers only to
become a quickly fading echo.
Things come to a shocking halt.
The moment we disappear,
the world starts to change.
There's an eerie silence in cities
that are suddenly, a little cooler.
The average human body puts out as
much heat as a 100-watt light bulb.
Take away eight million
people from New York,
and the entire city cools
down by a fraction of a degree.
Even though we're gone,
the machines we left
behind keep working.
All over the world, hundreds of
planes approach airport runways.
Most descend at over 100
miles an hour, and today,
all with empty cockpits, every
landing will end in a fireball.
Thousands of other planes fly
through the sky on autopilot.
Many will stay in the
air for a few more hours,
but when the fuel runs out, gravity
will pull them back to earth.
In a world without humans,
cities continue to function on
thousands of automated systems.
Computers keep in touch
with hundreds of satellites,
which will continue to transmit
information across the globe,
as long as the power stays on.
Power is generated by more than
50,000 power plants around the world.
In the US, coal-fired plants produce
half of the country's electricity.
To keep the fires burning,
they require a steady supply of coal.
But there will never
be another delivery.
The coal plants start to fail.
The Western grid is knocked
out by a rolling blackout.
The shimmering lights of Las Vegas
will never shine again.
The sun breaks through the clouds in
Pennsylvania, which still has power.
As temperatures rise, automatic
air conditioners turn on.
The need for electricity surges.
This area relies on wind
power in addition to coal.
Even without us, the wind
turbines are still running,
so there's enough power
to meet the new demand.
But at the local power station,
there's no one to decide
that more power is need.
Computers detect a problem and
shut down the entire system.
Pennsylvania is now without power.
Niagara Falls, Canada is home
to one of the world's first
commercial hydroelectric plants.
It provides power to
more than 2 million homes.
A mile upstream, water surges into
tunnels that snake under the city.
When it reaches the power plants, it
drives the turbines and creates electricity.
Less than two hours ago, people
were monitoring this powerful system.
But with no one at the
controls, the turbines flood
and the plant shuts itself down.
Seconds later, blackouts sweep
through parts of Ontario and New York.
The world-wide loss of electricity
reaches the nuclear power plants.
Automated systems detect that
the electrical grid is failing
and they shut off the reactors.
But this is just the beginning.
Six hours after humans disappear
the sun goes down in Europe.
The last power plants go offline.
The dark ages are back.
The sun is still shining on North America
and thousands of cars are still running.
Every gallon of gas
they burn sends 19 pounds
of carbon dioxide into the air.
This greenhouse gas can pollute the
sky for the next one hundred years.
Without us, another source of man-made
global warming is also disappearing.
Planes send out water
vapor in their exhaust
and the cold air transforms
the vapor into clouds.
But as the last planes
fall from the sky,
these man-made clouds
disappear with them.
Fuel-starved jets aren't the only
disasters rolling through this new world.
All over the globe, industrial plants
react to the permanent loss of power.
Some gases need electricity to keep them
cold enough to be stored in liquid form.
If they don't have power, the
cooling units stop working.
Eventually, the liquids come to a boil
and create dangerously high pressures.
Many tanks have relief valves
that vent gas to avoid explosions.
But hundreds of thousands of tanks all
venting at the same time is unimaginable.
The gases spread
wherever the wind blows,
and some are heavier than air,
a danger to any creature
that roots around in the soil.
The same chemicals that made
the modern world possible
are now set loose to destroy it.
Emergency back-up systems are sustaing
the world's nuclear power plants.
Automatic diesel generators have kicked
in to prevent a catastrophic meltdown.
But the diesel fuel won't last forever.
All over the world,
pets are getting hungry.
If they don't find food
and water soon, they'll die.
But they're not the
only animals affected.
The global power failure is also
impacting zoos and safari parks.
No longer contained by electric fences,
predators are free to
explore their new world
and its dangers.
Chlorine gas from a derailed
train killed this herd of deer.
Changes are also taking place
at some natural gas facilities.
With the power off, the liquid
natural gas is starting to vent.
But most of it's being burned off,
an automatic safety feature designed
to contain gas leaks at plants.
With the tanks venting, the
explosive gas can reach idling cars,
left behind when their
owners disappeared.
It only takes one small spark,
and the new world
echoes with explosions.
And this is just the start.
Fires like this will burn for days
as hundreds of chemical plants around the
world send dangerous toxins into the air.
In just six short hours,
our disappearance has triggered a
series of catastrophes around the world.
And as animals and atoms
infiltrate this world without humans,
a much bigger disaster could be looming.
It's been three days since
humans disappeared from the Earth.
Power plants have failed.
Machines have ground to a halt.
Thousands of tons of toxic chemicals
have escaped from the world's plants.
In London, England, Big
Ben is due for its winding.
But without the help of a human hand,
it rings for the last time.
Human time and human
history have stopped.
But life on Earth continues.
Houses and apartments are still
inhabited by increasingly hungry pets.
It's been three days
since anyone has fed them,
so they devour anything they can find.
In the US, tens of millions of dogs
were trapped when their owners vanished.
Now, they either have to break
out of their homes or die.
With the failure of power
plants around the globe,
pets inherit a dark world.
At nuclear power plants
emergency diesel
generators started working
as soon as the electricity failed.
But without power, this
building, and hundreds like it,
will soon cause an
unprecedented disaster.
This is the spent
fuel handling building,
where radioactive fuel
is stored in cooling pools
after it's used to generate power.
The pool is 30 feet deep and filled
with 400 tons of spent nuclear fuel,
the result of atoms splitting
to create nuclear energy.
And split atoms keep
releasing heat and radiation.
The spent fuel is
contained in zircaloy tubes.
And they're dangerous.
If they're not kept under water,
they'll quickly heat up to 1000 degrees.
They need to be kept in
flowing, refrigerated water
for years before they cool off.
Nuclear storage sites can
be found all over the world.
There are 75 in the US alone.
The spent fuel is safe as
long as the generators stay on
and keep the water cool.
But if someone doesn't refill them,
they'll grind to a stop.
And this time, no one's coming.
Pets are now learning
to live off the land.
For some, life was once
rich with food, water.
But now, scrounging through
garbage is what provides meals.
As for water, things have
changed down by the river.
Pumps at the sewage treatment plants
don't work without electricity,
so raw human sewage is
seeping into lakes and rivers.
Abandoned pets aren't the only
animals struggling to survive.
The world is filled with cattle,
1.4 billion of them, and without humans,
they too have been forced
to fend for themselves.
Now that we're gone, 90,000 cows a day
are saved from slaughter in the US.
But dairy cows need 100 pounds of food
and 25 gallons of water
every day to survive.
With no electricity, their
water supply is drying up.
The cows are on their own.
In a cruel twist of fate,
they're safe from the slaughterhouse,
but they may all die from dehydration.
And things don't look much
better for zoo animals.
Trapped in their cages,
many of them will die.
But those once contained by electric
fences are prisoners no more.
They finally break free.
Elephants need up to
400 pounds of food a day,
and finding it in the
suburbs will be a struggle.
These enormous herbivores
will give a serious
pruning to each neighborhood they visit.
Predators also prowl the suburbs.
These hungry lions have spotted
another escapee from the zoo.
But lions are skilled
hunters on savannahs,
not in public parks.
And climbing plastic is one
challenge they can't win.
With the baboon out of reach,
they need to find some easier prey.
Camels, on the other hand, are
having no problem finding food.
They eat almost any vegetation,
grass, leaves, even thorns that
other animals avoid are on the menu.
And with food at every turn,
camels easily adapt to
a world without humans.
The lions have moved
from the park to the porch
as they continue their search for food.
On both sides of the glass, an
unexpected and unusual sight.
Overhead, birds are migrating.
And without humans around,
many more will survive this year.
At night, birds use
the stars to navigate.
With the power on, lights and
glowing skyscrapers resemble stars,
so birds often circle them al
night and die of exhaustion.
But in a world without
humans, there is no power,
so migrating birds fly more
safely through major cities.
Millions will reach their destinations.
Their population will boom.
On city streets, dogs have
gone from pets to predators.
Within a week of losing
their human masters,
they're forming packs and
fighting for dominance.
Which hasn't happened since 2005,
when Hurricane Katrina forced
humans to evacuate New Orleans
and leave many dogs behind.
The dogs started hunting in packs
and threatening humans.
But not all dogs are equal.
With more than 400 different breeds,
some varieties, like this poodle, don't
have the size or strength to compete.
And like wolves, dogs
will kill their own,
so every small dog is a potential meal.
In the next few weeks, most
smaller dogs will be killed.
At nuclear power plants,
diesel generators are
finally running out of fuel.
The power goes off for good
inside the spent fuel buildings.
The cool water stops flowing.
The temperature starts to rise.
In just a few days,
the water will boil and evaporate.
And without people to stop it,
a nuclear disaster greater than the
world has ever seen is now inevitable.
A massive dose of radiation,
500 times greater than what was
unleashed on Hiroshima, will be released.
Dogs from the city are roaming
the countryside looking for food.
And they're hungry enough
to try just about anything,
even corpses.
The fields are littered
with dead dairy cows.
When we were around, dairy cows
provided us with milk for 8000 years.
Now, their rotting carcasses
will do nothing more
than sustain hungry dogs,
who just two weeks ago were probably
eating comfortably from a can.
Not all cows are dead.
In the wide-open spaces
of western North America,
free-range cattle are thriving.
But the same can't be said for the
domesticated animals trapped in pens.
1.5 billion chickens
have died in the US,
leaving only free-range poultry to
roam among a world full of predators.
Death is in the air.
A time bomb ticks.
This world without humans is
about to suffer devastating blows.
Ten days after humans
disappear from the Earth,
the power is off.
Cities are quiet.
Animals that escaped from
zoos and safari parks roam free
but fight to survive.
Predators are a problem,
but we left behind other deadly forces.
For days, super-heated
steam has been escaping
from the spent fuel building
of this nuclear power plant.
With no emergency power,
there's nothing to keep
the fuel from heating up.
The fuel burns through casings
and sets fire to everything in the room.
Radiation equal to 500 atomic
bombs is about to explode.
This is a nuclear disaster
and there's no one to stop it.
A deadly mix of radioactive
particles spews from the plant.
Some of them, like strontium 90,
will be dangerous for 300 years.
Plutonium will be radioactive
for 240 thousand years.
Pine trees near the nuclear
power plant are first to die.
Radioactive particles cling
to their bark and resin.
Chlorophyll, which makes
the trees green, is damaged,
and as a result, they turn red.
The last time a forest died like this
was during the Chernobyl
disaster in 1986.
Radiation contaminated an
area of 50,000 square miles,
the size of Alabama.
In a world without humans,
this scene is repeated again and again.
Nuclear power poisons
the earth we left behind.
There are 6 nuclear
power plants in Illinois.
Radioactive smoke fills
the streets of Chicago,
the site of the world's first
self-sustaining nuclear reaction.
Fires break out at many
of the 30 nuclear plants
located in the eastern US.
Each one is almost 20
times more radioactive
than the Chernobyl disaster.
Many of Europe's 173
reactors also ignite.
Their spent fuel burns.
Carried by the wind,
the radiation is an invisible poison
that settles over
thousands of square miles.
If we were still on the planet,
it would cause cancer
in millions of people.
Giant plumes of radioactive smoke
and particles spread across
the northern hemisphere.
Winds push radiation away
from the reactors in Europe.
If conditions are right, it could
reach as far as North Africa.
Radiation from some
of Japan's 53 reactors
drifts across the Pacific Ocean.
The world's most remote
islands are in its path.
Rain washes much of the
radiation from the sky,
concentrating its deadly effects.
Some areas become more
deadly than others.
Large animals flee areas where plants
have died from radiation poisoning.
But small creatures aren't as lucky.
Many live on the forest floor
where leaves and soil are
coated in radioactive particles.
Radioactive beta particles
can only penetrate half
an inch into living tissue.
For large animals like deer,
their vital organs are
spared a direct assault.
But it's different for small animals.
Their organs aren't so insulated.
Radiation cripples them.
In the worst hit areas,
over half of the
rodents and insects die.
For animals in the cities and suburbs,
they have access to food
that's much less radioactive.
Grocery stores can provide enough food
for city mice to last for generations.
They also make a
perfect breeding ground.
A female mouse can give birth to
more than 70 offspring in a year.
Since radiation has killed
many of the mice outside,
this cat heads indoors,
where he just might get the 8 mice
a day he needs to stay healthy.
Humans need a variety of
foods to get all the fat,
protein and vitamins we require.
Cats don't.
They can produce their own vitamin C,
and they can get the rest by eating
the organs and entrails of mice.
All over the planet,
animals are invading the
human world to find food.
And what we left behind
will keep them alive,
even as clouds of radiation spread.
Radiation has dissipated.
Cities are quiet and the
atmosphere is improving.
The air is clearer.
In Manhattan and Toronto, the view
has increased from 20 miles to 100.
City dogs still roam the
countryside looking for food.
Most of these former pets
are far from skilled hunters.
But if they're hungry enough,
they'll try to attack anything once.
Like wolves, dogs hunt by instinct,
going for the legs or neck
to bring down a large animal.
But instinct is no match for a
beast weighing thousands of pounds.
The dogs aren't a threat.
And without humans,
the elephants are predator-free.
In just a few months,
pets and zoo animals have become killers
in a radioactive world.
But another challenge is on the horizon:
winter.
Six months after humans disappear.
It's early December.
In a world without us,
former zoo animals and
pets either adapted or died.
In some parts of the world,
animals are about to
face their next challenge:
the coming winter.
A common misconception is that
cockroaches can survive almost anything.
But cockroaches are
imports from the tropics
and only spread north as we
started to use central heating.
With the electricity
gone, and the furnaces off,
millions of cockroaches
will be dead by the new year.
For other animals,
our sudden disappearance
isn't a problem,
it's an opportunity.
Raccoons and squirrels already know
that the best way to survive the cold
is to sleep through it.
And this winter, they have
many new dens to choose from,
that are drier and safer
than sleeping outside.
These squirrels are tree
dwellers, so they camp upstairs.
Skunks, on the other
hand, prefer the ground.
Hibernating animals don't need heat,
even when their body temperatures
drop almost to the freezing point.
It's a survival strategy their
ancestors evolved long ago.
But this African elephant isn't equipped
to deal with frigid temperatures.
His body evolved to get rid of heat,
not keep it.
In Africa, his thin ears would
have helped him keep cool.
But now, they're just
getting frostbitten.
To survive, he needs to head south.
After winter comes a
spring like never before.
In the forests near ruined
nuclear power plants,
it's a silent season.
Poisoned by radiation,
these evergreens have lost their
ability to grow new shoots and branches.
But further from the power plants,
spring helps repair the
damage we left behind.
Rain washes radioactive
debris from leaves and bark.
Poisonous atoms are driven underground.
They're still a threat to
anything that lives there,
but our radioactive fingerprint
is starting to disappear.
And that's not the only threat
to animals that has vanished.
Without humans there is no one to hunt.
And a population explosion of
animals takes over the empty spaces.
This new world is filled
with new opportunities.
It's almost been a year since
every car on Earth ran out of gas.
In their last year on the road,
cars pumped 7 billion tons of
carbon dioxide into the air,
more than one ton for
every person on Earth.
This greenhouse gas
accounted for half of the impact
humans had on global warming.
But now, the carbon dioxide will be
cleaned up faster than ever before.
In spring, new plants and
leaves need carbon to grow.
They draw it out of the air,
naturally cleansing a polluted planet.
New trees soak up more
carbon than old ones.
This spring, nature has
many new places to grow.
For the past ten thousand years,
we've been imposing
our will on the planet.
In downtown Los Angeles,
two thirds of the land is
covered in roads and parking lots.
We made our mark in the suburbs, too.
In the US, lawns and golf courses
cover an area bigger than Florida.
Now that we're gone,
nature is reclaiming the Earth.
Nothing is immune.
Millions of miles of roads and highways
are slowly being invaded
by moss and lichen
and all they usually need is water.
Cracked roads are filled
in with moss and grass.
A once carefully groomed
soccer field now grows wild.
Fast-growing trees take root
where children once played.
All these new plants
allow nature to soak
up greenhouse gases like
carbon dioxide faster
than when humans were here.
Year after year,
our grip on the land is loosening.
It's been thirty years
since humans disappeared.
At night, the only light comes
from the moon and the stars.
Once, Earth was so well lit
it was easily seen from space.
But thirty years after
the lights went out,
Earth's inhabitants watch
a new kind of light show.
Hundreds of strange shooting
stars fly through the sky.
A few even make it to the ground.
The fiery wreckage contains clues
that these are not normal meteorites.
These shooting stars
are some of the last
survivors of the space age.
Humans left 25,000
objects orbiting the Earth.
Most of it was junk,
clamps, pieces of rockets,
remnants left from our 50
years of working in space.
And without us
there's nothing to keep it from
falling back where it came from.
When solar storms erupt
on the surface of the sun,
radiation expands the Earth's atmosphere
and slows orbiting
satellites and space junk.
Gravity does the rest.
Satellites in higher
orbits have been slowly
spiraling closer to the
Earth for the last 30 years.
Now, with dead batteries,
they plummet to the ground.
Back on Earth,
the world continues to change.
Human homes slowly collapse.
Plants and animals help
speed up the process.
For three decades
animals have gnawed
through roofs and walls.
Dirt and seeds have blown into houses.
Living rooms have
become homes for trees.
Rain falls into dining
rooms and kitchens.
Ceilings and floors rot and fall apart.
Schools once taught about
human triumphs over nature.
But in just thirty years,
nature reclaims much of
what humans took away.
Changes are especially obvious
along the world's coastlines,
where we built many of
our cities and homes.
Now, hurricanes wash them
away as if they never existed.
From Miami to Halifax,
mansions and cottages are destroyed.
Man-made global warming still
affects the world's oceans,
even 30 years after people
stopped polluting them.
While houses collapse on land,
remnants of the human world
create new homes for marine life.
At least 50,000 ships
are strewn along seashores
or rusting on the sea bottom.
These shipwrecks are a
magnet for sharks and fish,
and they provide thousands of
places for fish to live and breed.
Above the waves, nature's
advance continues.
Humans used one third of all
dry land for farms and pastures.
But now, fields originally
planted with single crops
have been invaded by a variety of
fast-growing weeds and wildflowers.
Every year, forests
expand their territory,
growing closer to meadows
of bushes and shrubs.
It took us 10,000 years to
force our will on the planet.
Carve our mark on every continent.
Now, nature is invading
civilization's citadel:
the concrete jungle.
Welcome to a world thirty
years after humans disappear.
There is no power.
The screech of cars and jets
will never be heard again.
But cities are still filled with life.
Wild dogs hunt in packs,
roaming the roads and
sidewalks we once roamed.
Plants and trees are taking over.
New York's Central Park
is actually getting bigger.
Dirt and seeds blow through the
city and take root everywhere.
Manhattan turns from grey to green.
Times Square once was a hot spot
for millions to celebrate
the start of a new year,
now, it's being engulfed
by a blanket of green.
Nature is reclaiming the world,
city by city.
In London, young trees
sprout in Trafalgar Square.
In Berlin, a forest surrounds
the Brandenburg gate,
once the division of
East and West Germany.
Thirty years after we disappear,
glass tumbles onto deserted streets.
Once, glass-covered office towers
symbolized the modern age.
There was more glass
in one skyscraper than
all of the glass made
during the Roman Empire.
But most skyscrapers
were built using caulk
and metal clips to keep
the windows in place.
After thirty years,
the clips are rusting.
The caulking cracks.
Water gets into the cracks
and the frames get weak.
The era of the gleaming
skyscraper is ending.
High above them, hawks and
other raptors are on patrol,
keeping an eye out for scampering prey.
The concrete jungle is born.
Relics of human existence
slowly disintegrate.
After years of neglect,
paint peels away.
Raw metal is exposed to the elements,
rust spreads.
The steady advance of
nature also damages concrete.
This was once a train station
crowded with commuters.
Now its concrete roof is falling apart.
Concrete is strong,
but extremely porous.
Rain washes away the
limestone used to make it.
Stalactites grow a centimeter
every year and then break off,
slowly weakening the concrete.
This roof will collapse
in less than 20 years.
Humans may be gone,
but we're still contributing
to this destruction.
We burned fossil fuels and
pumped tons of carbon dioxide
into the air for more
than a hundred years.
Now, the planet is slowly
getting rid of our pollution.
As carbon dioxide returns to earth,
it mixes with rainwater
and produces carbonic acid,
which eats away at the world's concrete.
Much of our modern
world rose from concrete.
Now, these soaring buildings,
engineering marvels,
are ready to fall.
Cities all over the
world face the same fate:
a slow disintegration.
Without windows, high-rise offices
are now occupied by birds and animals.
Exposed to the elements,
ceiling tiles and drywal are no match
for more than half a
century of wind and rain.
Rust is everywhere.
Moisture has penetrated
the walls and doors,
and paint peels off every surface.
But the damage goes deeper than that.
A city like Paris gets up to
25 inches of rain every year.
Now that the windows are gone,
nothing can stop the rain from
flooding the concrete skeleton
of this office tower
and creating cracks.
The cracks are caused
when carbon dioxide
penetrates the maze of
microscopic pores in concrete.
Then, it winds in until
it reaches the rebar,
metal that gives reinforced
concrete its strength.
Rebar is usually hidden
from the outside world,
but now, the carbon dioxide
is causing the bars to rust.
As the rust radiates out
from the steel, it expands,
splitting and cracking the concrete.
The building is under attack
from the inside out.
Cracks are appearing all over the world,
and there's no one around to fix them.
When people were on the planet,
problems like this would be repaired.
But now, cracked concrete
can't be reinforced or replaced.
The damage runs unchecked.
And the changing seasons
only makes matters worse.
As water turns to ice
it expands and puts more pressure
on the crumbling buildings.
The constant freezing and thawing
makes the cracks grow.
In just one hundred years,
the concrete becomes too fractured
and brittle to support its load.
The upper floors collapse
and their combined weight
crushes the floors below.
The building crumbles to the ground.
Our cities are disintegrating.
The planet is absorbing
what we left behind.
120 years after humans disappear,
many modern skyscrapers have
collapsed into heaps of rubble.
Concrete walls have been destroyed
by a steady onslaught of air and rain.
But the new landscape has
made cities a little cooler.
When we ruled the planet,
heat from the sun was soaked
up by black roofs and roads.
Asphalt absorbed 95
percent of the sun's light.
Black surfaces made cities up to 10
degrees hotter than surrounding areas.
But now that we're gone,
asphalt is being covered
by grasses and trees.
Shade keeps the ground cool.
The temperature drops.
The world's climate is changing.
Manmade global warming is
finally coming to an end,
thanks to oceans.
For the past 120 years,
churning waves have absorbed carbon
dioxide into the top layers of the seas.
Then, microscopic plankton and
shellfish absorbed it into their bodies.
Many died and sunk to
the bottom of the ocean,
taking our carbon dioxide to the depths.
After the last cars stopped running,
much of their exhaust
is finally being buried.
Our impact on the climate is declining.
The changes are being felt
all around this new world.
In Berlin, young trees attract new life.
The saplings growing out of the
concrete provide food for animals.
But where there are deer,
hunters are sure to follow.
These wolves have come
in from the country.
Most of the wolves in Germany
were killed by humans long ago,
but these hunters are from Poland.
And wolves aren't the
only predators around.
When we disappeared, millions of
domesticated dogs had to fight or die.
At first, the dogs had an
enormous edge in numbers,
but they were facing a
battle they couldn't win.
Many of the newly liberated
pets were neutered.
Unable to reproduce,
they lost their advantage
and slowly died out.
But not all dogs disappeared.
Those that managed to survive
adapted to the new reality
and mated with wolves.
Now they look more
like Australian dingoes,
medium sized with straight
hair and long snouts.
Genetically almost identical,
dogs and wolves were
kept apart by humans.
But in a world without us,
dog and wolf genes are mixing,
assuring the future
of the canine species.
And this new generation
is thriving in cities.
One hundred twenty years
after humans disappear,
thousands of wolves hunt across Europe.
They need to eat every few days, so
they're lured by their prey downtown.
The urban jungle becomes
a new killing ground.
There are some places getting colder
and whiter than when humans were here.
With no black roads or roofs,
some cities definitely suffer the chill.
In northern cities, more
snow falls and stays longer.
But packs of wolves and dogs
still manage to find food
through these cold winters.
South of the freezing
temperatures are rivers,
diverted by humans
for power and commerce.
This is the Thames
River, in London, England.
Humans tried to tame it
for more than 1000 years.
Once, the Thames was a
gateway for thousands of ships.
But its high tides and storm surges
often threatened to flood the city.
So, one of the world's
largest systems of floodgates
was built to hold the waters back.
But without people,
the river is out of control.
Tides have sucked boats into bridges,
creating dams and forcing the
Thames to flow around them.
The banks are flooded.
London returns to the marsh
that the Romans found
here 2000 years ago.
In the American southwest,
the problem is too little water.
This is the Imperial Valley
in Southern California.
Once, it provided half of America's
winter fruit and vegetables.
With 350 days of sunshine,
some crops had four harvests a year.
But only three inches
of rain falls annually.
The dry air helps preserve buildings,
but it's deadly for crops.
People intervened to
make this desert bloom.
Farmers brought in 977
billion gallons of water
each year from the Colorado River,
enough to cover every surrounding
field in six feet of water.
But when we disappeared,
the irrigation stopped.
What was once California's
farming miracle
is now a barren desert.
Another manmade oasis can
be found 300 miles northeast.
Las Vegas.
Built in the middle of a desert,
its casinos and fountains used
water brought in by electric pumps.
When the power went
off, the taps went dry.
Now, with just a few
inches of rain a year,
the desert is reclaiming the city.
But nature hasn't erased
all evidence of our presence.
This is the Colorado River.
It hasn't changed much in the
150 years since we disappeared.
But long ago, it was
much deeper and stronger,
it even helped carve the Grand Canyon.
Today, the Colorado is still
a shadow of its former self.
Dozens of dams were built
to harness its strength
and keep it from reaching
the ocean as a torrent.
Humans also built reservoirs
to contain its massive power.
And there the waters will stay as long
as the dams can hold the river back.
200 years after humans disappear,
nature has taken over
many of the world's cities,
but some rivers are still
shackled by concrete monoliths.
Dozens of dams still hold
back the Colorado River.
The largest of all is the Hoover dam,
just 25 miles from Las Vegas.
It's as tall as a seventy story building
with a base as thick
as two football fields.
Enough concrete was poured to pave a
highway from New York to San Francisco.
By blocking the Colorado River,
the dam created the
reservoir of Lake Mead.
There's enough water here
to bury the state of New York
under a foot of water.
This is the water that once fed the
fountains and swimming pools of Las Vegas.
The Hoover dam is mostly
made of solid concrete.
But even this mammoth
monument is vulnerable.
The reason lies up the Colorado River
near the border of Arizona and Utah.
This is the Glen Canyon dam.
It was created to store water for nearby
cities and to generate electricity.
But this dam has a major weakness:
its spillways,
which act like an overflow
drain on a bathtub.
If the river level gets too high,
the excess water escapes
through the spillway tunnels
so it doesn't go over
the top of the dam.
But the spillways can't
handle sudden floods.
The threat is high in the mountains.
When winter storms produce
unusually high snowfall,
the heavy spring run-off
creates surging floodwaters.
They rush head-on to the dam.
After rusting for two centuries,
the gates that controlled
the spillways have collapsed.
The water races through 700 feet
of tunnels deep inside the dam.
And as it does, it creates
a destructive pattern.
Low-pressure bubbles form in the water.
When they pop, they cause
supersonic explosions that
eat through the rock into the dam.
Once, special concrete ramps
prevented this from happening.
But after 200 years without humans,
erosion has taken over the tunnels.
600 billion cubic feet of water
bursts through the dam
and gushes downstream.
The surge is over 50 feet high.
It sweeps through the Grand
Canyon toward the Hoover Dam,
which was built to hold back 45,000
pounds of water per square foot.
This is its greatest test yet.
The water pours over the Hoover dam,
sweeping away everything in its path.
The Colorado River rages
southward at 25 miles an hour,
swamping dozens of dams on its way.
18 hours later it reaches
the Gulf of California.
And for the first time in centuries,
the Colorado River meets
the ocean as a flood,
not a stream.
The release of the Colorado
will transform this
part of North America.
Fish from the ocean will
come to this estuary to spawn.
A vast marsh, once one of
the wonders of the Americas,
will be revitalized.
Hundreds of species will find new homes
as river and ocean combine.
Nature is reclaiming the world.
In France, parts of
Paris are a marsh again.
In California, irrigated
fields have reverted to deserts.
And Manhattan is a forest.
As altered rivers return
to their natural state,
silt creates new land.
Coastlines change.
South of New Orleans, over 200
square miles of swampland re-emerges,
lost when humans dammed
up the Mississippi.
Our sudden disappearance
is affecting the oceans too.
Once, we took 518 million pounds
of fish from the sea every day.
Now, with no trawlers to catch them,
fish live longer and grow bigger.
Cod have tripled in size,
growing from just a foot
or two up to six feet.
Much larger creatures are
also recovering in our absence.
Whales are thriving after
200 years without people.
And they've had a lot to recover from.
Before the petroleum industry,
whales were a major source
of oil for machines and lamps.
Most whale hunting declined
when humans started
extracting oil from the ground.
But many species remained on the brink
of extinction for centuries to come.
The reason: large modern ships.
In our last 50 years on earth,
the number of ships worldwide doubled.
So did the noise they generated.
Some of the sound from these vessels
carried for miles under the oceans.
As a result, whales could no longer
hear each other's mating calls,
and they rely on sound to find
mates up to a thousand miles away.
With humans gone,
whales' mating songs are being
heard from Canada to the Caribbean.
After 200 years,
our impact here is vanishing.
The oceans once again teem with life.
But on land there are still
relics of humanity that remain.
We built symbols of our
power when we ruled the earth.
But how long will they last?
It's now 230 years
after humans disappear.
Few signs remain
that an intelligent, creative
species once lived here.
One of the grandest is also one of the
world's most recognizable
modern monuments:
the Eiffel Tower.
Over a thousand feet tall,
it was constructed in
1889 for a world exhibition
and was meant to be torn
down twenty years later.
But the French fell in
love with their Tower,
and it became one of the most
famous landmarks in the world.
This 19th century marvel of construction
was designed by bridge builders,
and it's been standing
now for centuries,
outlasting even modern skyscrapers.
The lattice structure gives the Tower
strength without using much metal.
And the entire tower
weighs just 7,300 tons.
When people were still around,
the Eiffel Tower was covered in 60 tons
of paint to protect it from the elements.
But 230 years of weather
has taken its toll.
Rain has flaked away the paint.
Rust eats away at the Tower's iron.
With every rainstorm, the
entire structure erodes
and becomes more brittle.
Now, the Tower is vulnerable
even to moderate winds.
Normally, its support beams
can withstand these winds,
but now, they're too weak.
Three centuries after it was built,
the Tower comes crashing down.
Paris's landscape changes forever.
Monuments and buildings
can't adapt to this new world;
they're frozen by the
techniques used to create them.
But species can evolve
as conditions change.
Here, in the forests of Paris,
animals that we left
behind have adapted.
Most of these pigs are
descendants of pink pigs.
They thrive in the shadow
of the ruined Eiffel Tower.
These feral pigs bred with
surving domesticated ones
to create a hearty, tough
animal with dark fur.
They are survivors in
the new world without us.
Even while the modern
world collapses around them,
those that adapt survive.
Another symbol of human ingenuity
stands on the other side of the Atlantic.
How has it changed in the two hundred
thirty years since we vanished?
The Statue of Liberty was built
in 1886 of massive copper plates.
She's three years older
than the Eiffel Tower.
Since humans disappeared,
some parts of her are
faring better than before.
Acid rain used to eat away at her skin,
stripping her of one
pound of copper every year.
Pollution coated her nose
and cheeks with black grime.
But cleaner skies
have led to a cleaner statue.
Liberty's skin has benefited
from the absence of humans,
but other parts of her body haven't.
Over the centuries, a forest
has grown up around her
and it's littered with copper plates.
The plates are about as thick as two
pennies and can last a thousand years.
So why is the Statue of
Liberty losing her skin?
After 230 years, the statue's
arm has finally collapsed.
If copper is the statue's skin,
iron bars are its skeleton.
And like the Eiffel Tower,
these iron bars have rusted through.
The shoulder bars became too weak
to hold up the arm and its torch.
Now, this symbol of freedom
is only visible to wildlife.
The Statue's arm and
torch were first to fall,
but that was just the beginning.
More than two hundred
years have taken their toll
on some of our most iconic monuments.
It's only a matter of time
before they disappear forever.
Signs of the human species are becoming
harder to find in North America.
The eastern half of the continent
is covered by immense forests.
Without us to cut them down,
trees are growing 90 feet
tall and blocking the sunlight.
But the trees do more than tower
above old suburbs and roads,
they bury them.
After two hundred thirty years,
falling leaves have created
three feet of new soil
and cover nearly
everything we left behind.
Occasionally, rain-swollen streams
reveal the remains of human existence.
This is all that's left of a home,
centuries after the wooden
beams and floors rotted away.
Plastic from modern houses
also litters the ground.
This cell phone is still intact,
more than 200 years
after the last phone call.
It may survive for centuries.
Most metals have rusted through, but
stainless steel is truly stainless.
This kitchen sink may last
for thousands of years,
but for animals to last,
some need to adapt.
In the West, caribou and deer roam over
millions of acres of former farm land.
And once again, so do the
thunderous hooves of bison.
Their herds can grow
by 30 percent a year.
From a species of half a million,
their numbers are now reaching
into the tens of millions.
Other creatures also dot the
savannahs of the American West.
These furry beasts are the
descendants of millions of beef cattle.
Their ancestors mated
with Highland cows,
a breed insulated with fur, not fat.
Horses evolved here long
before humans arrived,
and once again they run wild and free.
In just 230 years,
North America has buried human homes
and lost some of its
most prized monuments.
And time doesn't stop,
1000 years after every
human disappeared from Earth,
the iron of the Eiffel
Tower is almost gone.
It has slowly eroded and
become part of the Seine.
In New York, the Statue of
Liberty has fallen into the forest.
Her iron skeleton finally gave way
and her body collapsed.
But her pedestal still towers
above the trees around it.
Made of solid concrete and granite,
it wil last thousands of years.
But time can wipe away
all evidence of humanity,
especially as the world turns colder.
A new ice age grips the planet.
Gradual changes in the Earth's
orbit take it further from the sun.
Snow will stay on the ground in
northern cities for two summers in a row.
Then, a chain reaction causes ice
to cover most of the
northern hemisphere.
It will stay here for the
next hundred thousand years.
Once again, glaciers travel south
and eventually reach Manhattan.
They'll grind down what's
left of the Statue of Liberty
and any other sign of human
civilization left in the north.
But there is one place our
imprint will remain indefinitely.
On the Moon.
Unlike Earth, the moon's
landscape changes very slowly.
Craters more than 4 billion
years old are still preserved.
Along with some human artifacts.
A car.
A television camera.
The only reminders of the human species
that will last for millions of
years aren't even found on Earth.
Planet Earth is four point
five billion years old.
In that context,
human civilization is
just the blink of an eye.
It took us 10,000 years
to cut down half of the world's forests,
but after we disappear,
they grow back in just 500 years.
Once we used half of all fresh water
and changed the course of half
of the world's major rivers.
But some dams were washed
away in just 200 years.
We pumped 13.5 billion tons
of carbon dioxide
into the air each year.
But in just a couple hundred years,
plants and oceans were
scrubbing the earth clean.
It took just over a century for
our major cities to start crumbling,
for forests and swamps to cover
what used to be concrete and asphalt.
The planet was even able to handle
the nuclear legacy we left behind.
After we disappeared,
thousands of tons of radioactive
particles were released.
But nature was able to bury most of it,
and some animal species
not only survived,
they thrived.
Earth is resilient.
And time, it cleaned up
every mess we left behind
All we had to do...
was get out of the way.