Original subtitles

[dramatic music]

- [Narrator] What would happen if every human being

on Earth disappeared?

No matter how we might vanish,

this is the story of what could happen to the world

we leave behind.

Now, on "Life after People,"

Since the dawn of civilization,

humans have fought to conquer the desert.

But when we're gone...

The sand seeks to swallow up everything we've built,

from America's playground...

- Imagine the City of Sin,

literally cooking from the inside out.

- [Narrator] To the tallest building on Earth.

- This isn't just a dust storm.

It's a sand blaster the size of a city.

- Humanity's greatest triumphs wither in the sun.

Monuments crack in the heat.

And our footprint is swallowed up by the sands of time.

Welcome to Earth, population zero.

[soft music]

[soft, tense music]

Across the globe, farmland sits silent. There's no planting.

No harvest.

In the Imperial Valley,

these abandoned fields were brought to life

by sheer human will,

wrestled into existence where nothing should grow.

- California's Imperial Valley

is a half million acre agricultural powerhouse.

One harvest out of there produces enough fruit

and vegetables and meat to feed every single person

in New York City for a year.

- Keep in mind,

this is all happening in the Sonoran Desert,

one of the most extreme deserts on Earth.

- [Narrator] In this thirsty stretch of land,

the daytime sun blisters the ground

with 115 degree heat,

before plunging down to 40 degrees at night.

- It's also dry as a bone.

To qualify as a desert,

an area needs to receive less than 10 inches of rain a year.

The Imperial Valley receives less than three.

So this farm in paradise had to be completely man-made.

- [Narrator] In a place where nothing was meant

to grow, mankind carved new veins into the landscape.

A marvel of steel and stone that poured life

into the arid desert.

- It took 10 years to build

the longest irrigation canal in the United States.

It's an 80 mile long concrete channel called

the All-American Canal.

It draws water from the Colorado River,

downhill into the Imperial Valley.

- Every year this system moves 840 billion gallons of water.

- [Narrator] For nearly a hundred years,

this system has defied mother nature,

creating a man-made oasis.

But it's one that relies on human vigilance.

- Normally, a small army of water managers

or ditch riders works around the clock,

acting like air traffic controllers for irrigation.

- A man is assigned to a ditch to make sure

the right amount of water goes to the right field

at the right time.

No more, no less.

- [Narrator] Now, there's nobody left to man the ditches.

No one to adjust the flow of water.

- Any gates that were left open would

have water just flooding out onto these fields.

You're just going to have this patchwork of lakes,

each of which has a bunch of dead vegetables floating

on the surface.

- The Imperial Valley is so vast

that while some parts would be flooded, others,

where the gates were closed, wouldn't get any water at all.

In the triple-digit heat, this land would quickly die.

- [Narrator] It took years of human engineering to make

the desert bloom.

But in only 48 hours,

mother nature reached out her hand and laid it to waste.

300 miles north, deep in the scorched heart

of the Mojave Desert, lies Las Vegas.

The casinos are empty now, no dealers at the tables,

no gamblers at the slots.

But it still burns bright,

a neon mirage flickering against the emptiness.

- The Las Vegas Strip is a 4.2 mile stretch

of just absolutely pure spectacle.

It's hotels, it's casinos,

and more than 10,000 miles of neon tubing

and 12 million lights.

- The city itself outshines entire countries

in electricity consumption, guzzling over 8,000 megawatts

of energy a day.

That's the same rate as Paraguay or Iceland.

- [Narrator] Beneath the stillness

of the glittering city, something hums.

An automated multi-source power grid built by human hands

to keep the current flowing.

Even when no one is left to use it.

- In Vegas, the demand for power fluctuates wildly,

from sleepy off-season nights to packed casinos

in 100 plus degree days.

- During the daytime it can run on solar.

At other times it can run off hydroelectric power

from the Hoover Dam.

And if it needs a little extra juice,

it's got natural gas plants that can do that.

- Problem is, even this super advanced system

needs humans to maintain it.

On the hottest days,

workers maintain transformers' cooling systems

so they don't overheat.

And solar panels need to be constantly cleared of dust

and debris that would otherwise render them useless.

- [Narrator] Just as the lights were always meant

to do, they're drawing crowds.

But these visitors come writhing and twitching in the night.

- So many insects are attracted to the light.

You know, moths, flies, bees, wasps, mosquitoes.

Under normal conditions, they would

be orienting themselves by moonlight.

You introduce artificial light and it confuses them.

And they end up spiraling

towards these multiple sources of light.

- As nearby towns go dark,

Vegas becomes a magnet for every light-seeking insect

in the area.

- Grasshoppers have been a huge problem

for Las Vegas in the past.

One night in 2019,

the lights attracted an unbelievable horde of them.

It's estimated that 46 million grasshoppers descended

on the city, terrorizing locals and tourists.

- The swarms of grasshoppers were

so thick they looked like clouds.

Scientists were even able to track

their movements using weather satellites.

- [Narrator] The Bellagio was alive with movement,

blanketed by insects.

The MGM Grand wriggles,

covered in a thick layer of grasshoppers.

And the city's lifeblood,

its electrical transformers are being swarmed as well.

- Essentially, transformers take

the electricity generated by power plants

and convert it into smaller doses for us to use

in our homes and businesses.

This is sort of like taking a fire hose

and converting it down to a kitchen faucet.

- The problem is you've got all these insects

swarming and nesting and blocking the ventilation.

- Normally, crews would clear the transformers

and cool them down, but not now.

And the hotter they get, the oil inside them degrades,

the wires expand, the insulation weakens...

I mean, it is a perfect recipe for ignition.

- [Narrator] Without warning, the silence is shattered.

[explosion booming]

One transformer erupts in a shower of sparks. Then another.

And another. It's the beginning of the end.

- Those explosions would come so fast

and furiously that it would sound like someone

was making popcorn.

Only the kernels were sticks of TNT.

- It would be like the most gruesome,

destructive fireworks show you've ever seen.

- [Narrator] After more than a century of unbroken glow,

the brightest city on Earth goes dark.

The Strip, once a beacon of excess,

is swallowed by blackness.

But parts of the city are still smoldering.

All it will take is one gust, one ember,

and Las Vegas will light up the sky one last time.

- [Narrator] On the border of the sun-scorched

Arabian desert lies the city of Dubai.

A metropolis once inhabited by over six million residents.

Now home to none. The advanced rail system is abandoned.

And the famous Dubai Fountain dances for no one.

- For centuries, Dubai was just

a small backwater in the Arabian desert.

But then, in 1966, they struck oil.

At the peak of their oil boom,

they were raking in $42 million a day.

And they invested all of that into becoming

a major economic player.

- Dubai went from a small fishing village

to the second largest city in the Middle East.

They built the biggest port in the region and became

a crucial shipping hub,

handling 10% of the world's cargo containers.

- They built beaches and even man-made islands

to encourage tourism.

They built 100,000 hotel rooms for visitors to stay in.

- [Narrator] Two weeks after people,

there's no one to refuel

the natural gas-powered turbines

that supply electricity to Dubai.

And they spin their last,

blanketing its vast malls and artificial islands

in haunting silence.

But in the heart of the city,

one building still hums with life.

Deep inside, backup generators whisper.

A faint mechanical heartbeat in a world gone still.

It's a towering pillar of glass and steel,

raised up by human hands in the face

of nature's harshest elements.

It's the tallest building on the planet. The Burj Khalifa.

- Dubai wanted an iconic landmark to put it

on the map, so to speak,

to compete with cities like New York City and London.

So they went with a tower that stretches 2,716 feet

into the sky with 160 floors.

It's about two times as tall as the Empire State Building.

- The environment in Dubai is punishing.

Temperatures can get to over 125 degrees Fahrenheit.

And on top of that,

you've got these incredibly strong winds

and sometimes sandstorms.

- [Narrator] The tower was boldly built

to withstand the desert.

A shining beacon of human ingenuity.

But beneath it, in the dry, blistering heat,

danger lies hidden beneath the sand.

- The Burj Khalifa is just two

and a half miles from the Persian Gulf.

That means salt water.

And that salt water is constantly seeping

into the ground underneath Dubai.

- The building stands on the shoulders

of 192 concrete piles driven deep into the Earth.

As water seeps in, the soil swells and pushes

against them, probing as if looking for a weakness.

- To protect itself, the Burj has a massive pumping

system designed to deal with groundwater.

It can remove up to 20 Olympic-sized swimming pools

of water in a single year.

- Even if all the pumps went out,

the engineers designed what's called

a cathodic protection system,

which is essentially a way to use electricity

to prevent rust.

- Beneath the tower,

a current pulses through the steel in its foundation,

a ghostly force field that halts the chemical dance

that causes metal to oxidize and rust.

- But of course, this system relies on the power staying on.

- [Narrator] One month after people,

with no one to maintain them,

the tower's backup generators have been living

on borrowed time.

- The backup generators run on diesel fuel,

and even with those tanks completely full,

at most they're going to last a couple of weeks.

So after people, those things will be dead in no time.

- [Narrator] The last generator sputters and dies.

The electrical heartbeat that once guarded

the Burj Khalifa's foundation fades into silence.

The building's last sentinels have abandoned

their posts, leaving the tallest building on Earth exposed.

In California, four weeks without people,

and the Imperial Valley is being reclaimed by the desert.

Fields withering, choking beneath a pitiless sun.

Nearby lies the Salton Sea.

Once another man-made oasis in the sweltering sands,

now the biggest lake

in California sits abandoned, derelict,

and baking in the heat.

- The Salton Sea,

it was essentially made by accident.

Back in the early 1900s,

engineers were trying to divert water

from the Colorado River into the Imperial Valley

when a retaining wall on one

of the irrigation canals collapsed.

That caused water to divert and go

into this natural depression

in the Sonoran Valley called the Salton Sink.

- The area flooded for an entire year,

and by the time it stopped,

the entire Sink was full of water.

It was transformed into a lake about the size of the city

of San Diego.

- By the 1950s,

the Salton Sea became a hotspot

for activities like fishing, boating,

and other water sports.

So the water was continually diverted there to keep

the water level high.

But as the population of Southern California grew,

cities like San Diego needed more water.

So less was diverted,

and eventually the Salton Sea started drying up.

- As the water receded

and the salt levels spiked,

fish began dying off in huge numbers.

At that point, the only water being input

was agricultural runoff, filled

with fertilizers, pesticides, and toxins.

The sea effectively became a lake of poison.

- [Narrator] With the Imperial Valley drying up

and no water runoff flowing into the Salton Sea,

it's evaporating fast.

And all it leaves behind are salt, sludge,

and something far more dangerous,

waiting to rise with the wind.

- As the water recedes,

chemicals used in farming over the years have built up

in that dust.

Chemicals like DDT and arsenic.

And so as that dry lake bed gets stirred up

by the winds, that dust rises up, and so do the chemicals.

And they're all spread over the entire area.

- And you might think, after people,

those chemicals wouldn't matter.

But they do because those chemicals are also corrosive.

- And for animals, it's even worse.

Damaging the lungs and kidneys, irritating skin,

and even messing with fertility.

- [Narrator] From the parched bed of the Salton Sea,

toxic dust begins to rise.

Now the Santa Ana winds awaken,

screaming across the valley at 70 miles an hour.

They twist the air into poisonous gusts.

And when they pass, nothing they touch will be the same.

Three months after people.

Las Vegas is no longer the city of lights.

It's a city of smoldering flame.

Exploding transformers have left behind pockets of fire,

and they're hungry for more fuel.

- One of the easiest ways for fire to spread

is through dense vegetation.

But Vegas has spent years getting rid of that vegetation

and leaning more into desert landscaping

to reduce water usage.

So there's just not that much left to burn

in the area, except our buildings.

- [Narrator] Now something sinister is looming,

threatening to turn the remaining relics of mankind

into a funeral pyre.

- Las Vegas itself is very dry.

But during the summer,

thunderstorms can develop in the surrounding hills,

and they can send strong winds down into the valley.

- Wind is the number one reason fires spread.

Burning embers can be carried by the wind up

to two miles, landing on a roof and starting

a whole new fire.

- [Narrator] Without warning, fire erupts.

[fire roaring]

First in the heart of East Las Vegas,

then among the lonely murals of the arts district.

Finally, it claims the Strip.

Neon signs melt, buildings ignite.

What was once a playground of excess becomes

an inferno devouring itself.

- Picture the Mandalay Bay in flames,

then the Luxor, Tropicana, MGM Grand, all those iconic

Sin City landmarks swallowed by fire.

- Within only a couple of hours,

the casinos would start to lose structural integrity.

You'd see the roofs cave in and the walls collapse.

All the glitz and glamor just melt into charred rubble.

- [Narrator] Las Vegas is a flaming ruin.

The only question that lingers in the smoky air

is how long before what's left is swallowed up

by the desert.

- [Narrator] Five years after people,

the tallest tower ever built rises proudly

from the desert sands below.

But the seeds of decay have already been planted,

and its enemy is slow and patient,

a siege that rises from below inch by wet, salty inch.

- The tower doesn't look much different above ground,

but without power,

the system that prevents the salt water corrosion,

you'd see tiny cracks forming in the concrete piles

that the whole structure rests on.

- The Burj has now been sealed up,

baking in the Arabian sun.

It's basically a greenhouse with temperatures reaching

as high as 150 degrees Fahrenheit.

- Thanks to the Persian Gulf,

humidity hovers around 60% during the summer.

Condensation will be building up on the walls

and the ceiling of the units.

It would be so wet,

it would look like it's drizzling inside.

- First, mildew would start to grow

on furniture and carpets, and then comes the mold.

The drywall would start to rot and the wood in doors

and inside the walls would start to warp and bow.

- It's amazing how fast the illusion

of luxury can just disappear.

The rooms in the Burj Khalifa would start

to look run down really fast.

Discolored, stinky, almost like the hallways

and the rooms are melting.

[dramatic music]

- [Narrator] 15 years later,

and the elements have shown no mercy.

The sun is unforgiving.

- The constant heat, moisture,

and UV rays from the sun will start to break down

the sealant that keeps the windows in place.

- Windows start falling out of their frames

and chunks of glass fall loose from the structure

and crash down onto the street below.

- [Narrator] The tower's skin is peeling away,

flaking off like old paint,

but inside something far more insidious remains.

57 elevators suspended thousands of feet in the air,

their cables weakening with each passing year.

How long will it be before gravity overwhelms them?

[dramatic music]

In the Imperial Valley,

what was once lush farmland

is completely unrecognizable, reclaimed

by the brutal Sonoran Desert.

- All those once thriving crops are long gone,

and the Salton Sea has completely disappeared.

- The dry lake bed is now exposed.

Dangerous heavy elements like selenium and arsenic,

and even traces of DDT are kicked up by the wind

into a dust cloud,

and this poisonous cloud spreads across the landscape.

- The strong desert winds in Santa Ana will carry

this arsenic-laced dust all across Southern California.

We're talking thousands of tons of poison.

The fallout will carry on for decades.

- [Narrator] The cloud of death drifts westward,

hunting its next target, a desolate, arid city,

its bones already being picked clean

by the elements, Los Angeles.

- LA isn't technically a desert,

it's more like a dry Mediterranean climate,

but 25 years after people,

it's well on its way to becoming one.

- This is a city that knows very well

the dangers of life in a hot, dry climate,

and without the vigilance of its citizens,

most notably firefighters, LA would be in rough shape.

- [Narrator] But high on its hill,

an LA icon still overlooks the sand-choked city.

- Thanks to a steel makeover in 1978,

the Hollywood sign is still standing.

Steel melts at about 2,500 degrees Fahrenheit,

which is much hotter than most wildfires.

So while Los Angeles crumbles, the sign remains,

a lonely testament to the dreams Hollywood left behind.

- Over time, nature would take over.

Hardy desert plants would creep in, topsoil would erode,

and the city would start to resemble the arid landscapes

of the Mojave.

- The only sort of twisted good news would be

that the threat of fire would fade

as the most flammable material would be slowly buried

under the desert sand.

- [Narrator] The city's freeways scrawl across

the land like a spider web, cracked, sun bleached,

and littered with the husks of abandoned cars.

But among them, a predator once held in check by humanity

is on the prowl again.

- LA's 528-mile freeway system may keep cars

moving, but it also traps mountain lions,

cutting them off from habitats and mates.

- In the time of humans, driven by instinct,

young males will risk almost anything,

including putting their lives on the line by trying

to navigate LA's deadly freeways.

- [Narrator] But after people, the engines are silent,

the lanes are empty,

and for the first time in more than a century,

nothing stands in their way.

- The mountain lions

are now roaming free, expanding their territory,

finding mates, and strengthening their gene pool

to secure their species' future.

- [Narrator] But just as these kings

of the canyon reclaim LA's streets,

the deadly cloud of airborne toxins

that has been swarming toward the city finally arrives.

[dramatic music]

- [Narrator] 25 years after people, once a dream factory,

Los Angeles is now a nightmare.

Its streets are buried beneath scorching sands

and prowled by hungry mountain lions.

And from the east, something worse is coming,

a toxic cloud rising from the corpse of the Salton Sea.

- We're talking arsenic, selenium,

pesticide residues, raining down

on the city like some kind of chemical fallout.

[lion growling]

- Wildlife that once thrived in the absence

of humans, like mountain lions and coyotes,

now have to deal with contaminated food

and water sources. - With little water, no shade, and almost no

prey, sticking around would be a death sentence.

The lucky ones would migrate north to cooler,

wetter regions like the Sierra Nevadas or Oregon.

Those who stayed would either adapt into smaller,

tougher desert hunters or die out.

- [Narrator] Los Angeles was already a ghost town.

Now, 25 years after people, wildlife abandons it

as well, leaving nothing to witness what's left

of it be consumed by the desert.

[dramatic music]

In Dubai, the tallest structure ever built still pierces

the clouds, but it's being slowly,

methodically undermined by decay.

And now, a new threat rises and an invasion takes root.

- Back in the 1970s,

the UAE imported mesquite trees from Central America,

hoping to green up the desert around Dubai.

On paper, it sounded like a brilliant idea.

These trees grow insanely fast, they provide tons

of shade, and they handle salty water like champs.

But nobody realized the monster they were unleashing.

- Roots spread up to three feet

in each direction, hogging nutrition.

And nothing survives under its shady canopy

because it releases chemicals

that suppress other plants' growth.

- [Narrator] A small army of groundskeepers once kept

the trees at bay, but after people,

they spread like a virus.

Roots cracking pavement, branches clawing

at stone, smothering the base of the tower.

- Mesquite roots grow extremely deep,

sometimes 150 feet.

These deep tap roots allow them

to access underground water

so they can survive drought conditions.

- Mesquite roots find their way into the cracks

of the foundation, widening them,

letting salt water in, accelerating decay.

Soon, the whole thing could collapse,

so what salt water began, the roots might finish.

- [Narrator] While the building's foundations choke

and rot, a new threat descends from the very heavens it

was built to touch.

[lightning crashing] - Tall buildings

are always prime targets for lightning.

In the flat desert, the risk increases,

and when it's the tallest skyscraper ever built,

the risks are even higher.

- [Narrator] The building's only defense is a relic

of human engineering.

A lightning rod that channels each strike safely

through the structure and into the ground.

- But this system is meant to withstand

about 100 lightning strikes before it requires

a human hand to repair it.

And the Burj Khalifa experiences an average of 10

to 12 lightning strikes every single year.

- [Narrator] Without people to maintain it,

the rod is little more than a decoration.

Thirty years after people,

it won't take a natural disaster to breach it,

just a run of the mill thunderstorm.

- Considering that a typical lightning strike

is about 300 million volts of electricity,

that's enough to jumpstart

about 25 million dead car batteries,

you don't want that kind

of violent energy anywhere near your skyscraper.

[lightning crashing]

- A lightning strike won't just hit, it will spread.

[lightning crashing]

The bolt jumps through the smaller metal supports

into the weaker parts of the building,

and when that much voltage hits fragile glass, boom.

- [Narrator] The strike rips through the upper floors.

Glass and debris rain down. Flames erupt, spreading fast.

The tower is burning.

- With no fire suppression systems working,

even a small blaze could spread quickly.

Down ventilation ducts and empty hallways

until the entire building was engulfed in flame.

A burning beacon on the empty skyline.

- [Narrator] The crown jewel of human construction

is rotting from the ground up and burning from the top down.

The question isn't whether or not it'll survive,

it's what will finally bring it down.

[dramatic music]

- [Narrator] Fifty years after people,

the city of sin is now a grim ruin.

What's left of the once glitzy casinos is crumbling.

[explosion booming]

The concrete giving way to relentless heat and time.

- Any protective sealant that used to reflect heat,

that has long since worn off.

And so now you've got these hot Las Vegas days,

these cold Las Vegas nights,

and that is a perfect recipe for severe thermal cracking.

[concrete cracking] - Thermal cracking

is when the concrete heats up ten degrees or more above

the surrounding air, it starts to stress and crack.

And the bigger the temperature difference,

the worse it gets.

- [Narrator] Unlike the ancient ruins it was built

to evoke, Caesar's Palace is cracked, broken,

and crumbling into dust.

- Now you might be thinking,

why can I visit Roman ruins that are thousands

of years old, when in Las Vegas,

Caesar's Palace disintegrated in just a few years?

Well the reason is something called quicklime.

- Quicklime is made by heating limestone until it becomes

a chalky powder.

And then when you mix the powder with water it forms

a super sticky glue

that can hold rocks together for centuries.

- The best thing about it though

is that you're going to get cracks that form over time,

but once they do, water gets inside the cracks,

that causes the chemical reaction

to get triggered again, and you end up

with this magical, self-healing concrete.

Even better, the mixture pulls carbon from the air,

turning it back into stone.

So not only does it fix itself, it makes itself stronger.

- It's crazy, ancient Roman concrete actually got

stronger over time.

Whereas everything we use today breaks down

under heat, water, and stress, leading

to cracks, erosion, and eventually a total collapse.

[dramatic music]

- [Narrator] The desert is overwhelming what's left

of the strip.

[metal crashing]

The Stratosphere, Mandalay Bay, Luxor,

and Bellagio are already among its victims,

but it's got far bigger ambitions.

[dramatic music]

In Dubai, the tallest tower ever built has been battered

by lightning and corroded by rust.

It still stands, the last great relic

of a vanished civilization,

but a threat has been hanging inside the tower

for over a century, one which could spell disaster.

- There are 57 elevators in the Burj Khalifa,

and elevator cables begin to weaken and break down

in temperatures above 150 degrees.

Any elevator cars on the upper floors

are now being held up by weakened cables,

which are deteriorating in the sweltering heat.

- [Narrator] After 150 years,

the tower's elevators hang by a thread.

[dramatic music]

All it would take is a strong wind to unmoor them,

and on the horizon, a sandstorm is gathering strength,

a leviathan of wind and grit, called a haboob in Arabic.

It is ancient in name and approaching

with primordial fury.

- A haboob isn't just a dust storm.

It's a dust tsunami.

These beasts can stretch 60 miles wide,

tower several miles high,

and blast through with winds up to 65 miles an hour.

Basically, they're a sandblaster the size of a city.

[dramatic music]

[dramatic music]

- [Narrator] The Burj Khalifa has stood for a century

and a half since the time of people.

Now, a massive sandstorm swallows the tower,

scouring it with windblown grit.

Inside, elevators long forgotten and corroded begin

to snap one by one.

[elevator crashing]

Echoing through empty shafts like the cracking of bones...

- These 57 elevators weigh anywhere from 21,000

to 27,000 pounds each,

and the one dropping the farthest is going

from a height that's taller than the Empire State Building.

- The elevators would hit the foundation

at the speed of over 200 miles per hour,

with each elevator striking the base with a force

of over 800,000 jackhammers.

- [Narrator] With this final blow to its foundation,

the tower collapses and is swallowed up by the desert.

[dramatic music]

200 years after people, Las Vegas is all but erased,

and only echoes of its former glory remain.

- The once glitzy strip would be a weed-choked wasteland.

The remnants of the neon signs would be poking

through the sands.

Maybe you'd still see the husk of Caesar's Palace.

Its Roman columns toppled like some lost civilization.

- [Narrator] But one relic endures steadfast.

A monument to what once was.

- Leo, the MGM mascot.

45 feet tall and weighing 50 tons.

- Still standing, looking over

the glittering empire that was.

- Bronze is basically nature's tank.

Unlike iron that degrades over time when it's exposed

to the elements, bronze does something different.

It makes its own armor.

It produces something called patina.

- A patina actually protects it,

sealing it off from further damage.

So while steel crumbles and wood rots,

that bronze lion will just sit there happily

for thousands of years.

[dramatic music]

- Across the globe,

mankind's footprints are being swallowed up

by the sands of time.

- The Sahara desert is already massive.

It's about the size of the contiguous United States.

But here's the real kicker.

Since 1920, it's been growing by an area the size

of Delaware every single year.

And it shows no sign of slowing down.

- [Narrator] The Sahara alone has swallowed

over 220,000 square miles,

an area the size of France completely consumed by sand.

And cities like Los Angeles are full-fledged wastelands

of dust and dunes.

- LA by now would endure months

of 95 degree plus days every year.

Rainfall would have plummeted by up to 80%,

turning the city into a desert.

- It'd be absolute devastation straight out

of a Hollywood apocalypse.

Skylines crumbling under the shifting sands.

LA would be a ghost of itself.

- [Narrator] For millennia, humanity battled

the desert, chiseling cities from dust

and forcing life where it wasn't meant to exist.

But in just a few centuries,

the wind erases the lines we drew

and the sand reclaims almost everything we left behind.

- Something that we have to remember is just

how many resources

and how much human upkeep actually goes

into protecting these structures that we built

in dry desert climates that maybe we should not

have been building in the first place.

- Humans rolled the dice on the desert,

reshaped it and forced it to bend to our will.

But without us, well, the house always wins.

Mother Nature takes it all back.

[dramatic music]