Original subtitles

WILLIAM SHATNER: A nuclear meltdown

that turned an entire city into a wasteland.

A ruthless disease

that decimated the human population.

And a giant wave

that emerged so suddenly,

there was no chance to escape.

It's a terrifying thought

that one natural disaster could destroy an entire city,

leaving behind only rubble and death in its wake.

And even with the assistance of modern technology,

the ability to determine the path of a hurricane

or foretell a sudden volcanic eruption

remains somewhat unpredictable.

But what about devastation on a global scale

that is caused by mankind itself?

Are we on a path to become

the architects of our own destruction?

Well, that is what we'll try and find out.

♪ ♪

♪ ♪

SHATNER: In northern Ukraine

stand the remains of an abandoned city

known as Pripyat.

Pripyat was founded by the Soviet Union in 1970

to serve Chernobyl, the nearby power plant.

At its height, nearly 50,000 people lived here,

but today, Pripyat's streets are empty.

Its buildings have fallen into disrepair.

Nature has reclaimed large portions of the city.

And it's all because of a tragic event

that took place on April 26, 1986,

an event known as the Chernobyl disaster.

MICHIO KAKU: In 1986,

we were horrified to see the greatest

nuclear accident of all time

emerge at the Chernobyl nuclear power plant.

The reactor went out of control,

creating an uncontrolled chain reaction,

like a small atomic bomb,

blowing the roof right off the reactor.

A huge amount of radioactive material

shot through the roof,

and then, into the atmosphere.

SHATNER: 36 hours after the explosion,

officials finally determined that the residents of Pripyat

needed to be moved to safety.

The city was then evacuated in less than four hours.

NIGEL RAAB: They were evacuated

very, very quickly at that point.

And when they're evacuated,

they can only take certain things with them.

Small things.

And the government

put guards outside of some of these apartments,

basically saying, "We'll protect your material,"

suggesting the residents

would actually go back to Pripyat,

which they never did.

Pripyat was built to be a self-contained town,

which had everything for the workers

of the Chernobyl power plant.

So that meant kindergartens to send their kids to,

all this leisure activity.

So the Soviets, in that respect, were getting better

at providing their workers with facilities.

Working at Pripyat would be a much better gig

than different towns in the Soviet Union.

LUCAS HIXSON: Before the Chernobyl

nuclear disaster in 1986,

Pripyat was a city of dreams for the residents

and the people that lived around.

It offered amenities and resources

that would not be found in nearby cities and villages.

After the accident, people were evacuated,

and they were forced to leave their hopes

and plans for the future behind them.

And that's really what we see in Pripyat today,

is what was left behind.

It is a ghost town.

Pripyat is an example of an abandoned place

that was vacated in a great hurry.

And so, of course,

you have vehicles that are just left abandoned...

...you have household objects,

children's toys,

kitchen utensils that were just dropped

in the middle of meal preparation.

There are a lot of hopeful murals

about science leading you into a proud future,

and they're in buildings that have been abandoned

for over 30 years.

That's something that is sort of impossible

not to feel the weight of.

SHATNER: While the nuclear meltdown

was caused by both human error and technical failures,

there are some former residents of Pripyat

who claim that the Chernobyl disaster

was actually destined to happen.

HOROWITZ: Some of the workers at Chernobyl,

in the days immediately preceding the explosion,

and following,

reported seeing this mysterious winged creature

with blazing red eyes.

This creature, which is referred to

as the Black Bird of Chernobyl today,

was thought to be some sort of a warning or...

a kind of crisis apparition.

The concept of a harbinger of doom

is incredibly common and incredibly long-standing.

Probably the most famous example

is the Horsemen of the Apocalypse--

the Four Horsemen--

who are said to foretell the ending of the world.

So when Chernobyl explodes,

the Black Bird of Chernobyl

was not just a strange sighting in the sky.

People start to think

that maybe this wasn't so much an accident

as it was something predestined.

SHATNER: Is it possible that Pripyat was destined to be abandoned?

As far-fetched as it may sound,

many locals believe the answer is yes.

And for further evidence,

they point to a prophecy of death and destruction

that is written in the Book of Revelation in the Holy Bible.

McNEILL: It's interesting because the word "Chernobyl"

is the Ukrainian word for "wormwood."

And Wormwood has a lot of historical

and cultural affiliations with poison,

with bitterness, with darkness.

And we see that-- most poignantly, perhaps--

prophesied in the Bible,

that there will be seven angels blowing seven trumpets.

And trumpet number three

is the trumpet that causes the "star called Wormwood"

to fall from the sky

and poison the land and the waters,

so that people who drink the waters will die.

The story could be an amazing symbolic description

of a nuclear power plant exploding

and irradiating the landscape,

so that people who live in that space,

who touch those objects, who drink that water, will die.

It's really compelling to see that connection.

And it is hard to simply write it off as a coincidence.

HIXSON: You can imagine

the way that people reacted to this story

after the disaster in 1986.

The people that lived in this region

were highly dependent on water for their way of life,

and their lives were forever disrupted

by the radioactive materials

that were thrown out of the reactor

on the night of the disaster and left in the environment.

HOROWITZ: When you add up these different elements,

the spotting of a winged creature

or some sort of a harbinger of doom

and the fact that a falling star in the Book of Revelation

has the same name as the nuclear power plant itself,

you can understand how some people read meaning

into the Chernobyl disaster.

SHATNER: Whether the fate of Pripyat was predestined

or simply the result of modern technology gone terribly wrong,

this abandoned city continues to spark

both fascination and fear.

But not all catastrophic events are triggered on a grand scale

like the size of a nuclear meltdown.

For instance, one of the deadliest plagues

in human history was caused by a creature

barely visible to the naked eye.

SHATNER: Officials from the California Department of Public Health

alert residents that a woman has tested positive

for a dangerous and quite unexpected disease:

The bubonic plague,

otherwise known as the black death.

RAJ DASGUPTA: Does the bubonic plague still exist?

The answer is yes.

And it's amazing how, many centuries later,

you could say this with a calm voice.

What is the difference?

The answer is antibiotics.

We know that if you have symptoms early,

that antibiotics can save your life.

KIRSTEN FISHER: While it's not as prevalent anymore,

the plague is certainly still in circulation.

In the United States, right, in more rural areas

where people come into contact with rodents

that might be infected with it,

it's still known to, like, crop up here and there.

The worst case of the bubonic plague that there was

was known as the black death,

in the middle of the 1300s,

and that wiped out 60%

of all of Europe's population.

SHATNER: 12 trade ships arrive

from the Black Sea,

and drift into the port of Messina to unload freight.

As dock workers approach the vessels,

they discover a disturbing scene.

DASGUPTA: The port master goes on board

to see the crew and, to their surprise,

it was almost like there were zombies on the ship.

Gangrene fingers...

big boils.

And if I saw a crew that had black fingers

and boils, let's be honest,

it sounds like a zombie apocalypse.

The black death seems to have been introduced

via the Silk Road,

which is a major trading route in the early medieval period

from central Asia,

where the bubonic plague regularly pops up.

Europe seems to have been largely unprepared

for this devastating event.

This is in the 1300s.

It went for quite a few years

and whole villages and areas were wiped out.

And like many plagues, uh, people wondered why.

DASGUPTA: These cities would get the plague

and no one knew why.

And then we always have the advantage

of looking back on history and tracing.

Historians could look back and say, "Wait a minute,

"all the cities with ports

"that do a lot of trading were infected.

"And what were going to all these ports?

Ships."

PHILLIPS: The black death was spread by fleas

that lived on rats,

and wherever these rats went, the fleas went,

and they bit people.

That's what made them ill.

CHRISTINE COLBY: The flea would actually vomit the bacteria

onto the person's skin while biting them.

The disease spreads to the body's lymph nodes

and causes buboes,

which are infected sores

which get to be about the size of an egg.

And they eventually burst and expel bloody pus.

The body goes through such horrific

and gruesome transformations,

that from the time you contract the bubonic plague until death

can sometimes only be a matter of days.

SHATNER: During the Middle Ages, many believed that demons

were responsible for the black death.

And people who were deemed

to be wicked or unworthy

were punished in hopes of driving the demons away.

TZADOK: Many people believed

that the source of this plague

was caused by evil spirits,

witchcraft and the like.

The powers of the occult.

And this led many people to seek out

any type of expressions

of the occult,

witchcraft and the like.

And to root it out in the attempt to placate God.

(screams)

SHATNER: Some were so convinced that the black death was

a scourge brought by evil spirits...

...they were willing to scourge themselves.

One common occurrence

during the time of the black death was

to see people that were called flagellants.

Which, they were under the belief

that they were being punished by God for their sins,

so they would publicly atone

and they would march through the town square

flogging themselves in the name of God.

(clamoring)

THOMPSON: This flagellation movement really exploded.

Whole towns flagellating themselves.

Those that didn't were accused of being with the devil.

PHILIPS: Something else that came from the black death was

the practice of selling holy relics.

When the black death was decimating Europe,

the Church were saying,

"Come to us.

We can cure you."

The bones of a saint

or something that had once belonged to a saint

kept in these churches, they were called relics,

and people believed that if they went there

or close to such relics,

prayed, that God may intervene

and protect them from the plague.

Now, they weren't curing anyone,

but people were still flocking to the churches

just on the hope that they could be cured.

DASGUPTA: So when we talk about the many lives that were lost

during the black death,

I think about a horror movie.

SHATNER: Historians estimate that the black death wiped out

anywhere from 50 to 200 million people,

at least a third of Europe's population.

So it's little wonder that most people thought

that something so destructive...

...must have been some kind of punishment from God.

But today, we have a much different understanding

of this disease.

GIGI GRONVALL: We call it the black death

but it's-it's a bacteria called yersinia pestis.

But it's not as dangerous as it was then.

Now, we have antibiotics, we can detect it.

You know, you can treat it.

SHATNER: Deep within the ocean floor,

a massive earthquake suddenly shakes the ground

for nearly ten minutes.

The energy released measures

an astounding 9.1 on the Richter scale,

which is the equivalent of 23,000 atomic bombs

exploding all at once,

making this disaster

the most powerful earthquake of the 21st century.

What happened was,

there are two major plates on the Earth

that are smashing into each other.

And when this happened,

it raised the sea floor there more than 100 feet

across 900 miles.

And what does this mean?

This means a tsunami is coming.

MICHAEL WYSESSION: Tsunamis happen

when something causes

the level of the sea floor to go up.

And when the sea floor goes up,

it pushes the whole water column up

and gravity causes that water to flow away.

This earthquake in 2004 created a massive tsunami

that spread all throughout the Indian ocean.

SHATNER: The enormous tsunami traveled across the Indian Ocean

at a speed of more than 500 miles per hour

and smashed into the western part of the island of Sumatra.

McGEE: Twenty minutes or so after the quake,

the nearest coastline in Sumatra

suffered a 100-foot wall of water that came in.

All but the tallest buildings were completely submerged.

So immediate destruction.

Two hours later,

that same wave traveling at more than 500 miles per hour

hits Thailand.

(people clamoring)

MAN: Get in, get in, get in!

SHATNER: 10-year-old Riley Sewell was

on vacation in Thailand with her family

when the giant tsunami struck.

RILEY SEWELL: We are playing on the beach,

and we look towards the shore,

and we see this thin white line is coming at us

and it's getting bigger and bigger and bigger and bigger,

and this was a 75-foot tsunami.

My mom is shouting, "Run! Run!" at the top of her lungs,

and we start running up this pathway up one of the cliffs.

You can just hear,

like this tsunami is loud and it's smashing...

...and it's, like, destroying trees,

but you can also hear the sound of people dying.

Sounds that no person should ever hear

and no person should ever experience.

Had we not found that pathway,

had we not run as fast as we had,

I wouldn't be talking and breathing

and speaking as I am right now.

SHATNER: While Riley Sewell and her family were

lucky to survive,

230,000 people

in 14 different countries perished

in what was one of the deadliest natural disasters in history.

WYSESSION: The tsunami killed people in Africa, in India,

and 70,000 people died on Sri Lanka.

So people all across the world

died from the huge tsunami that hit.

SHATNER: Frightening images broadcast around the world gave

billions of people a firsthand look

at the apocalyptic power of tsunamis.

And yet, this disaster was only the latest

in a long history of doomsday tsunamis

that have been recorded for centuries.

The earliest recorded tsunami happened

in the year 1630 before the common era,

when a massive tsunami spread

throughout the eastern Mediterranean at that time

and hit the island of Santorini, in the Greek Isles.

Now, interestingly, 1,200 years later,

the Greek philosopher Plato...

...wrote of the story of Atlantis,

which was a legend that had been handed down for years orally.

The story involved the destruction of an island

in a dramatic day and night, sinking beneath the waves.

And many anthropologists think that this legend

actually could be referring back to the tsunami

that hit Santorini.

SHATNER: A massive tsunami may have been the inspiration

for Plato's story of the destruction of Atlantis.

But on the other side of the globe,

the dangers of tsunamis were recorded in stone

on the island of Japan.

Japan is based on three major fault lines that collide,

making it one of the most geologically

active areas for tsunamis.

In fact, tsunami is a Japanese word.

Because tsunamis are a regular occurrence,

they put stone monuments saying, "In this year, on this day,

the water went up to this level."

SHATNER: Coastal areas such as Japan are still quite vulnerable

to the destructive powers of tsunamis.

But fortunately, scientists have created an early warning system

which can alert people before the next deadly tsunami strikes.

This technology provides people with a valuable resource

that our ancestors did not have:

the possibility to get out of harm's way.

There's a network of buoys, called DART buoys,

and these are pressure sensors that sit on the ocean seafloor

and can actually detect the pressure

of the tsunami wave as it goes over.

So, if a candidate earthquake is identified

and then verified, it goes into a warning system

that broadcasts a warning throughout the ocean basin...

-(alarm blaring) -...setting off sirens along coasts,

and alerting people by cell phone.

However, there's still many parts of the world

that don't have adequate coverage,

and we need a lot more sensors

to make sure that we do a better job

predicting and forecasting the arrival of a tsunami.

Can advances in early warning technology

save us from future tsunamis?

Or are these forces of nature so massive and unpredictable

that the destruction of entire cities is just a matter of time?

Either way, it's unsettling

to know that powerful forces on this planet

are entirely out of our control.

Like in the case of a never-ending fire

emerging from the Earth itself

that could burn for centuries.

SHATNER: Population: five.

Once upon a time, this small mining town

was home to more than 2,000 people.

Today, it's an almost entirely abandoned wasteland.

Some would say it resembles a war zone.

But it wasn't war that ravaged Centralia.

It was something much more devastating.

DAVID WHITEHEAD: The story of Centralia

is both tragic and terrifying,

in that it used to just be a quaint mining town...

...but now it's a total ghost town.

SHATNER: Valentine's Day.

12-year-old Todd Domboski

is playing in his grandmother's backyard

when he notices something strange

coming up from the ground.

He sees what he thinks is-is smoke coming up from the lawn,

goes over to investigate,

drops out of sight into a steaming hole

approximately 170 feet deep.

Saves himself by grabbing onto a tree root.

WHITEHEAD: So after what happened to Todd Domboski,

the media started coming in,

and Centralia became a big story.

REPORTER: Todd Domboski was playing when the earth

-opened up below his feet. -DOMBOSKI: I see the smoke,

and when I did, I just fell right through.

SHATNER: After a brief investigation,

the cause of the smoke in Todd's grandmother's backyard

becomes obvious.

A fire that was deliberately started,

and thought to have been extinguished,

had, in fact, never gone out.

And it was now being fueled by the vast reserves of coal

located underneath the town.

Centralia, uh, was a very typical, uh,

small coal town in the anthracite region

of Northeastern Pennsylvania.

Its only purpose for being was to mine coal...

...and its growth was in tandem with the coal industry.

As new mines opened up, more people would move there.

Some of those families in Centralia had been there

for as long as five generations.

And what I'm leading to is that

there's this massive labyrinth of-of abandoned coal mines

beneath Centralia-- really, under the entire town.

And so, in 1962,

the state dump inspector told Centralia borough council

that the location of its landfill

didn't meet state regulations.

And they arranged for the local fire department

to set the dump on fire to clean it up.

And they had done this in the past.

They would just go out and set it on fire,

let it burn for a while

and then wash it down with water from a tanker truck

and, uh, go away, everything's fine.

Except this time, it wasn't fine...

...because this fire had stayed smoldering in the garbage,

and then it moved into this labyrinth

of abandoned coal mines beneath the town

and that was how the mine fire got started.

And eventually, the fire broke out of the ground.

You could see glowing red rocks,

you could see, you know, blue burning rocks.

It's so, so hot.

If you got even, like, within ten feet of it,

and your face was-was frying.

You know? It was, it was that-that hot.

They sent the fire department back,

but the damage was already done.

WYSESSION: Attempts to put out the Centralia coal-seam fire

have been a total failure,

starting in 1962, when they first lit

that trash pit on fire.

That fire continued to spread underground,

despite multiple attempts to put it out.

And then, over a period of 20 years,

the fire just kept growing out of control.

To the point where smoke and steam

come up out of the ground, where the ground is as hot

as 900 degrees Fahrenheit in places,

just consuming the entire town.

REPORTER: The people of Centralia want to know

when the 20-year-old mine fire will be put out.

They appeared tired of living with the danger

of toxic gases entering their homes.

Representative Frank Harrison says, "It won't be easy."

WHITEHEAD: And it was at this point

that the town started to shut down and close shop.

REPORTER: Residents take a vote to move their homes.

The federal government forked over another

one million dollars to move them to safety.

WHITEHEAD: Businesses started closing,

people started leaving

and the government actually ended up buying the land

to stop people from coming back in,

because they realize at that point

that they had no way to stop this fire.

And sadly, this fire is raging right up to this day.

SHATNER: But why,

after nearly six decades,

why won't the fires go out?

WYSESSION: It's a question that's almost impossible to know

because not only can we not see through the rock,

any attempts to try to figure it out--

by drilling holes in the ground, for example--

you provide channels of air that can actually feed the fire.

And so, you can try to cut off the fuel

by digging out around it

to remove the coal to prevent it from spreading.

And you can also address the fire

by pouring water directly in

through channels underground

to try to cool that fire below its activation energy.

All of these were tried in the case of Centralia.

Not one of them succeeded.

You would think we understand fires enough

that we could, we could take care of this,

because we know, for a fire to occur,

you have to have an ignition source, a spark...

...then you have to have fuel.

Well, it's a coal mine, so coal is pretty good fuel.

But then you also have to have an oxidizer.

That oxidizer is-is air, in most cases.

But if they cut off the tunnels

or whatever's going into this mine,

no air should get down there, eventually all the air

should burn out and it should go out, but it's not doing that.

DEKOK: What I've been told by engineers is that

they could pump water down there for a year

and, if they turn the water off,

there would be a good chance there'd be enough residual heat

that the fire would start right back up again.

It's a tremendous monster.

JONES: Once an accident like this happens underground

where you have a fire burning,

as time goes on, the odds of putting it out

get fewer and fewer and fewer.

With a coal fire, you're talking temperatures

of 1,000 to 2,000 degrees Fahrenheit.

As the fire grows and grows and grows like this underground,

all that heat is radiated through the Earth.

It warms up the Earth and could get to the point

where you could see temperatures

of 200, 300 degrees on the surface,

and asphalt and different materials

actually start melting.

Sinkholes open up, houses collapse.

This can go on for a very, very long time.

In the case of Centralia, even to this day, 50 years later,

you see steam vents with toxic gases

being emitted out of the ground,

you see vegetation that has been destroyed

because of those gases and the heat.

This is almost a wasteland,

caused by these underground fires.

Some people have estimated that it'll take 200 years

for this fire to burn out,

and, in my estimation, nobody knows.

We could be talking, two, three, four, five hundred years.

There's no answer to that question.

It's basically hell on Earth.

SHATNER: Centralia, Pennsylvania,

once booming, now barren.

The ghost of a town that once was.

The few structures that remain

seem to defy the fumes to consume them.

Is the story a cautionary tale about the futility of mankind

trying to bend nature to its will?

Perhaps.

And it might be fire of another kind

that could wreak havoc

on a level modern man has never seen.

Because there are certain volcanoes

whose eruptions would occur on such a massive scale...

they could bring us to the brink of extinction.

SHATNER: At approximately 11:00 a.m.,

an earthquake measuring 5.0 on the Richter scale

sends great shockwaves

through the island's most active volcano,

Mount Kilauea.

The ground cracks open,

and 2,000-degree magma

boils to the surface.

As residents who live in the area flee for their lives,

a torrent of molten lava gushes from the broken earth,

destroying everything in its path.

McGEE: It was a massive volcanic eruption.

We're used to looking at volcanoes that look dormant,

and assuming that there's no threat.

But if there's one thing that the geologic history

of the Earth warns us about,

over and over and over again,

it's that there's unintended consequences

of the Earth being alive.

And Kilauea proved that in 2018.

Kilauea is a large volcano that sits

in the middle of the Pacific Ocean.

And it is generally known

for these lava flows that it puts out

that unfortunately got into a populated area

and this very large eruption unfortunately

destroyed over 700 homes,

destroyed some really pristine areas of the island.

McGEE: You have very kind of soupy,

watery lava that was racing at incredible speeds.

And the problem is, Hawaii is populous.

We have folks, many of them, who live there,

and there is nowhere to run.

I think the Kilauea eruption is one of nature's great warnings.

So long as the Earth is alive, we will face

the threat of major volcanic eruptions.

SHATNER: In 2018, Mount Kilauea topped

the U.S. Geological Survey's ranking of the most dangerous

volcanoes in the United States.

But according to experts,

even Kilauea's cataclysmic power pales

in comparison to others

that could potentially pose

great threats to not only cities,

but the entire world.

They're simply known as supervolcanoes.

Nuclear weapons? Yeah, we track them.

We know who has them.

Global warming? We have computer programs

that simulate global warming.

And meteors from outer space? We track asteroids.

But when it comes to supervolcanoes,

we know almost nothing.

A supervolcano could be 1,000 times more deadly,

leaving destruction on a scale that we haven't seen

in modern civilization.

POLAND: A supereruption is meant to describe

a truly extraordinary explosive eruption

that's about 1,000 cubic kilometers in volume.

That's how much material gets ejected.

SHATNER: According to volcanologists, there are,

at this very moment, between 12 and 20

active supervolcanoes scattered across the Earth.

We've all seen the devastation of volcanoes.

We see this catastrophe with all the gas coming out

of the volcano with all the debris and all the dirt.

But supervolcano eruptions can disrupt the atmosphere itself,

sufficient to affect the weather of the entire planet.

You've got sulfur dioxide, you've got particles,

which are reflecting sunlight,

and that bounce or trap

sunlight and thermal radiation.

And that completely changes the planet's heat balance.

You can cripple ecosystems from the bottom up

by darkening the world.

POLAND: These gases can also poison agriculture, poison plants,

and that of course will have a chain reaction

down the-the food web.

So, these eruptions can really cause a huge impact.

Even if the lava only affects one small area,

they can have a-a global impact.

Even thousands and thousands of miles away

from where the eruption occurred.

SHATNER: It's hard to imagine a supervolcano

causing a world-wide cataclysm, but one such event

is believed to have already occurred

long before humans walked the Earth.

An apocalypse that is referred to as...

"the Great Dying."

The Great Dying was a mass extinction of plants and animals

that occurred about 250 million years ago.

The largest that occurred in the history of Earth.

McGEE: Geologists call it the Permian-Triassic extinction.

It's the largest mass extinction

in the geologic record across all time.

And this is related to a major volcanic eruption

in northern Siberia that injected so much CO2

into the atmosphere that we lost 80%

of all marine life.

We lost 70% of all vertebrate land animals.

This was so bad, even the bugs got taken out.

So the Great Dying is one of geologic history's

great warnings that large volcanism can pose

a true existential threat to all life on Earth.

SHATNER: This body of water is one of the most popular

tourist destinations in the country

due to its natural beauty.

But deep below the lake's surface

lies an active supervolcano.

Taupo's a beautiful place.

It's serene, it's got a lovely lake, mountains,

geysers and hot springs.

Absolutely gorgeous.

McGEE: These nice low-lying areas

that tend to fill up with water and be very beautiful

often indicate,

lurking underneath you

is an emptied former supereruption.

The irony is, the beauty of a lake

often goes hand in hand with the lurking threat

of volcanic systems ready to go.

POLAND: The last supereruption of the Taupo volcano

occurred about 26,500 years ago.

We know Taupo is restless.

It has lots of seismicity, the ground goes up and down.

And scientists in New Zealand have tied that to magma

moving in the subsurface.

There's geothermal activity in the region

which indicates that the system's not dead.

It's alive.

It's on an active tectonic plate boundary.

So there are massive earthquakes that can be caused

by a supervolcano getting ready to blow

on a scale that we've never seen before or since in geology.

Where Taupo is,

large eruptions will eventually happen.

Volcanoes are something that humanity has always had

to live with and always will have to live with.

We can study these things, try to understand

how an eruption might occur.

But we don't have a way to stop a volcanic eruption.

We're not going to stop

something that the Earth wants to do.

SHATNER: Oxford University, July 2008.

A panel of experts from the Future of Humanity Institute

publish the results of a survey

regarding the global catastrophic risks

that humanity will face in the 21st century.

The results of the questionnaire are

both surprising and concerning.

Because the experts agree that there is

a one-in-five chance of human extinction

before the year 2100.

PAUL J. SPRINGER: At the 2008 Oxford conference, participants considered

nanotechnology, artificial intelligence,

and war to be the three categories

that were most likely to bring about such an event.

Personally, the one that keeps me awake at night

is the unbridled development of artificial intelligence.

It's partially because

of the weaponization of artificial intelligence

and what I like to refer to as the dark triad

of offensive, lethal, autonomous machines.

The possibility of programming errors

or of users deliberately inflicting these

upon enemy populations

is the type of thing that makes me nervous.

The development of artificial intelligence

is supposed to make lives a lot easier

but in practice might represent

the biggest existential threat of all.

When we see a civilization that effectively disappears

without a record of precisely why they left,

the answer is often rooted

in the development of advanced technology.

Because advanced technology enables

a larger population to live in a smaller area.

But if something happens to the resources themselves,

then you don't have the capacity

to support the population anymore.

EDWIN BARNHART: When I look at an episode like

Rome making an incredible drainage system out

of lead pipes, and then everyone goes nuts.

Is it all that different than a human society

building up technology to the point

where we forget that we're really

just part of an ecosystem

that's much more powerful than us no matter what we build?

SPRINGER: We have a tendency to assume that we can

always innovate our way out of the crisis of the moment.

There's also no guarantee that technology will save

a civilization when it's faced with an existential threat.

So what's it gonna be?

Will a deadly disease run rampant through the population?

Could a volcano block out the sun,

covering entire cities in suffocating ash and fire?

Or how about a nuclear disaster triggering

the apocalypse in the blink of an eye?

Hopefully humanity will avoid these catastrophes,

but since the final chapter in the history

of mankind is still unwritten,

just what or who will bring about

our end of days is a mystery that remains...

unexplained.

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