Original subtitles

This has got potential

for a major incident.

A wildfire races toward a sleeping California town.

Right now, guys, Paradise is on effin' fire.

Residents awaken to a nightmare.

I don't want to die here.

Scientists speed toward the danger zone...

Yes, that's a scan we want.

Risking it all to unlock the mysteries of fire.

It's not something that you can just observe it

and figure out how it works.

Paradise is lost.

We have witnessed literally an entire community gone.

It's the worst fire in a season of worsts.

But why?

A history of mismanagement.

Everywhere, foresters were trying

to do the same, silly thing.

A warming climate.

I think we're moving into uncharted territory.

And a building boom in the forest.

We're literally putting homes in the line of fire.

The stakes... and the flames... grow higher.

Right now, I'm wondering if we're in a good spot.

"Inside the Megafire,"

right now, on "NOVA."

Major funding for "NOVA" is provided by the following:

Major funding for "NOVA" is provided by the following:

Another sunny day

in the Sierra Nevada Mountains north of Sacramento.

November 8, 2018.

Skies are clear over Northern California today,

but it is going to be a very dangerous day for fire danger.

It's been more than 200 days

since there was any rain worth measuring.

The forest is bone-dry.

And now the wind season has arrived...

With a vengeance.

The strongest winds are expected across the Sierra,

where gusts could reach 60 miles an hour.

The stage is set for disaster.

Then, 85 miles north of Sacramento,

in a tiny hamlet called Pulga,

the wind blows a high-voltage power line off a tower

near the Camp Creek.

Sparks fly.

In 15 minutes, the first reports of fire come in.

It is 6:30 in the morning.

The Camp Fire has just begun.

When first responders arrive,

the flames are already so fierce,

and the winds so strong,

they have trouble getting close to the fire.

Eyes on the vegetation fire.

It's going to be very difficult to access.

Camp Creek Road is nearly inaccessible. WEBVTT 00:00:00.000.

Camp Creek Road is nearly inaccessible.

It's got about a 35-mile-an-hour sustained wind on it.

It's moving incredibly fast,

with a speed that stuns even veteran firefighters.

This has got potential for a major incident.

By 7:30, authorities issue an evacuation order for Pulga,

where the fire funnels up a canyon,

picks up speed, and explodes out over the rim.

The fire is now burning an acre of forest every second.

Firefighters cannot fight the flames.

Instead, they focus on rescuing residents.

In Pulga, it's already crossing that area,

heading towards the Concow area.

The fire consumes the small community of Concow

and heads toward Paradise, California,

where residents have just received immediate orders

to evacuate.

This fire starts,

and within minutes, it's hundreds of acres.

The man in charge of the state's wildfire fighting force,

Cal Fire,

is Ken Pimlott.

He's never seen anything like it.

Within an hour, it is in the town of Paradise.

Paradise.

Nestled in the woods high in the Sierra.

A close-knit community of 26,000,

many of them retirees drawn to the charm and beauty

of life in a small mountain town.

But along with it comes a looming vulnerability

about to be made hellishly evident

by the firestorm stampeding toward them.

Right now, guys, Paradise is on effin' fire.

I'm just going to get the out of Dodge.

This is getting heavy.

Residents attempt to flee...

Everything is burning.

My God, I mean everything.

Forced to run a gauntlet through flame.

There are only four roads that lead off the mountain,

and all of them are perilous.

Come on!

Just go!

Chaos captured in harrowing cell phone videos.

My God, there's fire everywhere.

I don't want to die here.

I don't want to die.

A tense escape from hell.

I'm scared!

It's Armageddon.

It's so hot.

Keep going!

HART Holy!

People are leaving their cars.

My God. It's okay.

What should we do?

We got to get out of here.

First responders race

to rescue hundreds of people trapped in their homes...

Are they coming for us?

Come on.

Watch out! Watch out!

Jess!

Cars...

Be Advised, on Clark Road at Skyway,

there's a woman in labor, she's in a beige Honda Pilot.

She's going to be honking her horn.

We have to get this traffic moving, now!

Even a hospital. WEBVTT 00:00:00.000.

Even a hospital.

All patients now out of Feather River Hospital.

All patients out and en route.

Go get 'em, boys.

Be safe.

It's now 9:30.

Just to the north,

in the neighboring community of Magalia,

George Gold would normally be up by now,

but today he sleeps in.

What woke me up was the wind.

We often have wind here; I think, "How nice."

I open the door, and it's windy.

I look up, and it's dark.

I thought, "It's going to rain."

I smell the smoke.

I said, "It's not going to rain."

I get dressed, I go outside, I look around.

At that point, the street wasn't burning.

But I could see fire,

and I thought, "This is the real thing."

He's lived here for 11 years,

drawn by the quiet and the beauty.

It is his dream home for retirement.

Now he must leave it all behind in a hurry.

Please, get out of town.

And as you're going out of town, please be careful...

But the roads are clogged with traffic and obstacles,

downed power lines, and trees.

Crews are racing to clear the way.

So George decides to wait.

He drives his prized convertible to a nearby parking lot,

hoping it will be safe there.

He records these images

as the fire closes in on his community.

You know, you stand here, and you just look around,

and the next thing, I see that the high school is on fire,

and it is just going up.

Just after noon,

the fire is still raging.

Many of George's neighbors are gathering

in another parking lot,

wondering if they are safe.

I couldn't get in at 9:00.

John Roberson has lived here eight years.

Now, this is kind of spooky.

So that's what I'm looking at.

As you can see, that's black smoke.

Our home right now is safe.

If it jumps up here to South Park Circle and Andover,

it's gone.

Nearby,

Mike and Alice Nutt are packing whatever they can fit

in their cars.

I got soda,

blankets, pillows, food, my animals.

My dogs.

They're my babies.

And then, I'm, I'm just scared, I am very scared.

We got our cars loaded up, don't know where to go.

6:00 p.m.,

less than 12 hours since it began,

and yet so much damage,

so many lives changed forever.

My God, half of our town is gone. WEBVTT 00:00:00.000.

My God, half of our town is gone.

55,000 acres burned;

At least 1,000 structures destroyed.

The Nutts' house?

Gone.

And so is the Robersons'.

George Gold is mesmerized

by what is unfolding before his eyes,

but now he knows it's time to get out.

He decides to check on his house.

When I came down here, everything was still burning.

So I came here, turned around,

I shot a couple of pictures, and I took off.

But the house was already completely engulfed in fire.

There is no hope for Magalia or Paradise.

And the Camp Fire keeps growing.

While George is driving toward safety,

meteorologist Craig Clements is headed

in the opposite direction.

He and his team are on an urgent mission

to shed some light on how wildfires spread.

Look at that... beautiful.

Yes, that's a scan we want.

It's dangerous work.

But the risk comes with the possibility

of a big scientific payoff.

That's interesting,

we're coming into some smoke here.

Perfect, perfect, perfect.

They are driving a one-of-a-kind custom rig.

They hope to peer into the fire

in a way that no one else has before.

We need to better understand fire spread,

and the meteorological data is one of the key components.

And yet we never measure things on an active wildfire.

We usually use a satellite.

We see plumes in the radar, which is great, but, you know,

we're not really seeing what's going on right here.

Plumes...

The columns of smoke and gas that rise from the flames...

Are more than a sign of fire.

They also create their own weather.

And Craig suspects that they actively spread the fire.

But how?

To understand, he aims a sophisticated lidar

right at the plume.

Lidar is like radar that uses a laser beam.

It bounces off the smoke particulates

as they are propelled by the wind

in and around the plume

and returns information about speed and direction.

We've been able to slice through a plume with our lidar.

And we've been able to measure rotation

and the wind field associated with a rotating column,

and so that's pretty exciting.

The plumes at fires like these are complicated systems.

As hot air rises, cooler air rushes in.

It's called fire-induced wind.

We don't know

how that fire-induced wind from the plume interacts

with pushing the fire front.

If the plume goes up, WEBVTT 00:00:00.000.

If the plume goes up,

does any air or smoke come back down?

And if it does come back down,

can that spread the fire in different directions?

It's these interactions

that we call fire-atmosphere interactions,

and we don't have a great handle

on how they propagate fire spread.

The Camp Fire continues to spread without slowing down.

Cal Fire says the town of Paradise

is pretty much destroyed.

48 hours after it began,

it has burned more than 100,000 acres...

A grim milestone.

It is now officially a "megafire."

Eventually, 86 lives are lost,

nearly 19,000 structures destroyed

in the most destructive fire in California history.

It stands apart, but it is not an isolated event.

One year earlier,

the second-most destructive fire, Tubbs,

burned more than 5,600 structures

and killed 22.

Little more than three months before Paradise is destroyed,

the Carr megafire devoured a quarter-million acres

and a thousand homes

in and around Redding.

Eight people perished.

And on the same day the Camp Fire began,

the Woolsey Fire started

in Los Angeles and Ventura Counties.

It burned 97,000 acres, killing three.

Of the ten most destructive fires in California history,

six occurred in the 13 months prior to the Camp Fire.

We are doing everything we can to respond and protect citizens,

but fire is part of the landscape in California.

This is the normal now.

And it's not just California.

Across the U.S.,

an area larger than the state of Maryland burned in 2018.

In the last 40 years or so, the amount of forest that burns

in any given year in the Western United States

has increased by about 1,000%.

That means

there's about ten times more forest burning this year

than there was in a year in the 1970s or 1980s.

All over the world,

wildfires are bigger, more frequent,

and more destructive.

In July 2018, fires killed nearly 100 in Greece.

In Sweden, fires burned above the Arctic Circle

in the midst of an unusual heat wave.

And huge fires burned in Canada, Russia, and Australia.

Why are we living in an age of megafires?

The big question is,

"Are these giant, destructive megafires we're seeing today 00:00:00.000.

"Are these giant, destructive megafires we're seeing today

"just the way forests burn,

"or is this somehow a new normal

"that we've created by our own actions,

forest management, and climate change?"

Near Paradise,

firefighters have more pressing questions on their minds.

Like how best to stop a fire driven by fierce wind

and steep terrain...

A major factor in its relentless spread.

Researchers are studying this

at the U.S. Department of Agriculture's.

Missoula Fire Sciences Laboratory.

If you are going to do fire research,

this is the place to do it.

This entire building is devoted to fire.

It's actually a pretty complex phenomenon.

It's not something that you can just observe it

and figure out how it works.

Forest Service scientist Mark Finney

showed us how they unlock the mysteries of fire.

So this is the burn chamber right here.

Everything we do in here

is designed to look at how fires behave.

On this day,

he and a dozen of his colleagues are preparing for a test

on a large, tilting burn bed of precisely cut cardboard.

What we can do is put these on the burn bed

in any kind of density that we'd like

to engineer whatever kind of fire we'd like...

How long we want it to burn,

how long the flames are, how fast it spreads.

The burn table brims with instruments

that measure pressure and temperature,

taking samples 500 times a second.

And there are cameras everywhere.

Today, they are trying to understand more

about how a fire spreads uphill, as it did near Paradise.

Okay, go ahead.

Line of fire, guys, good line.

Okay.

The flames are the visible sign

of rapid oxidation, or fire.

Fire requires dry, flammable material, or fuel,

oxygen,

and a heat source to create this chemical chain reaction.

Wildfires add two additional elements...

Weather and topography...

That determine how the flames

will grow and spread.

The reason we're measuring this

is that you can actually get fires

to accelerate extremely quickly going uphill.

Unlike the humans that fight them,

wildfires move much faster uphill.

When you have a slope,

you can't get air in from the uphill side

as easily as you can get it in from the downhill side.

If the slope is sufficiently steep,

all of the air is coming in from the downhill side.

With air fanning the fire

exclusively on the downhill side,

the flames get pushed into the slope,

putting them in contact with more fuel.

The tilted, climbing fire transfers a lot of heat WEBVTT 00:00:00.000.

The tilted, climbing fire transfers a lot of heat

to the trees and brush ahead of the flames,

preheating and drying them, making them more combustible.

You get very, very effective heat transfer

and a much faster-spreading fire.

This is what happened when the Camp Fire started.

The wind funneled the flames into a steep canyon,

and they rapidly accelerated uphill,

right toward Paradise.

On the morning after Paradise is lost,

the Camp Fire is still spreading.

Time for firefighters to report for the daily briefing.

Here.

Here.

Here.

All right, good morning, everybody.

I got 7:00, we're going to go ahead and get started

with the operational briefing.

Thousands of firefighters are here,

and more are on the way.

Okay, up here in Cresta area,

the fire has progressed to the east.

It's on both sides of the river,

continuing to eat its way downcanyon.

Good morning, everyone.

Incident meteorologist Alex Hoon

is worried about what lies ahead.

There's going to be a lot of shifting winds,

very dry conditions.

Use your lookouts, use your communication,

make it a safe day.

He taps into a suite of instruments

on the ground, in aircraft, and in space.

Orbiting 22,000 miles above the Earth,

the two-year-old GOES-16 weather satellite

captured visible and infrared images of the Camp Fire

from the beginning,

the big picture of a big fire,

an eerily remote vantage point

to utter chaos, death, and destruction.

This particular image,

it covers a time period

from about 6:00 a.m. in the morning

all the way until about 5:00 p.m.

when the sun begins to go down.

Within that 11 hours, we estimate,

it went from zero to about 50,000 acres.

And then the following 12 hours, it grew another 40,000 acres.

It released just an exponential amount of energy.

And that's what we're seeing here

on the satellite image.

A big factor in the exponential spread of the Camp Megafire:

Spotting.

Hot embers, also called firebrands,

launched and carried by 50-mile-an-hour winds,

landed as much as a mile ahead of the fire front.

New spot fires started again and again,

rapidly, randomly.

But exactly how spotting fuels the growth of megafires

is one of the big unknowns in wildfire science.

So it's still blowing northeasterly.

Craig Clements hopes his work might lead to some answers.

This is a real strong low-level jet

coming down off the mountains.

Right now,

wildfire prediction models are not sophisticated enough 00:00:00.000

wildfire prediction models are not sophisticated enough

to factor in all of the complexities

of the atmosphere and terrain.

And they don't account for spotting at all.

We are trying to forecast

how many spot fires there will be,

and that's something no model right now can handle.

Better models would help right now

to keep firefighters safe as they battle the Camp Fire.

But for people in Paradise,

there was no time for predictions.

Having gone through Paradise,

words don't describe it.

I mean, it, um...

A lot like the road to Baghdad during the first Gulf War,

when vehicles were abandoned...

That's literally what it looked like.

And we know some people perished on those roads,

and what those people went through,

and they really had no warning.

I think this is the first time

we've ever seen an entire town in California

wiped off the map by a wildland fire.

We have witnessed literally an entire community gone.

The megafire that wiped Paradise off the map

is more than just a big wildfire.

At this scale, the physics of fire changes,

greatly increasing the intensity.

But why?

At the Missoula Fire Sciences Laboratory,

mechanical engineer Sara McAllister

is seeking an answer.

When you have a really wide plume,

you're not pulling in air into the plume

as effectively as you are if it's a much smaller diameter.

In any fire,

colder air flows in to replace hot air as it rises.

Most of the time,

the air can come in from almost any direction,

chaotically.

It's what makes flames flicker and dance.

But the flames at the center of a megafire

are not fed by colder air from the sides or from above...

The surrounding fire and plume stand in the way.

So the only source of air for these flames is at ground level.

When that happens, the plume changes.

Sara McAllister conducts an experiment

to simulate that restriction of air from the side

using something you might find in your own home:

A chimney.

We were wondering,

"Does that restriction in air

influence the burning of the fuel underneath it?"

The idea is that we are scaling big-fire behavior

into a small-fire, lab-based experiment

and trying to understand what's different.

She douses a uniform bed of fuel,

in this case wood blocks...

Smells good, doesn't it?

With isopropyl alcohol.

Burns very nicely. WEBVTT 00:00:00.000.

Burns very nicely.

In the open, the flames are about five feet high,

as the air streams in from all directions.

Now watch what happens

when she slides the burning wood underneath the chimney,

blocking sideways air flow.

So we're looking at 15-, maybe 16-foot flame heights

off of a fuel bed.

Quite the increase.

There's a feedback.

When the fires get big,

all of that air that can't come into that plume

has to come in on the ground,

which is basically just stoking your fire.

The chimney effect created by giant plumes

makes megafires grow bigger, which further fans the flames.

It's a frightening feedback loop that gets even scarier

when a plume becomes a fire whirl.

Fire whirls that form on your average fire,

you see them for a few seconds, and they're gone.

And normally, they don't prompt too much concern.

But the biggest ones, literally fire tornadoes,

cannot be ignored.

Scientists used to think they were rare, even unlikely.

But as megafires become more common,

that is no longer the case.

Three months before the Camp Fire,

this is what happens in Redding, California.

The Carr Megafire spawns a deadly fire tornado

that generates winds approaching 165 miles an hour.

But what causes the flames to start spinning?

Wow.

This here is a fire whirl generator.

It's an apparatus that allows us to study how fire whirls form

and the structure of the vortex

that's produced inside the whirl.

Mark Finney says they begin with turbulent, strong winds

that send a lopsided current of air into the flames.

He demonstrates what happens next.

You'll notice at the beginning

that the flames are very disorganized.

But as the inflow begins to come in

in a swirling fashion,

the flames themselves become quite organized.

The air streams in faster and faster from the bottom,

fanning the flames, strengthening the whirl.

The burning rate of the fuel increases

by three to eight times as the whirl begins to develop.

The fire tornado in Redding

develops after the wind starts blowing inland from the Pacific.

When it collides with the fire,

it creates powerful, swirling winds.

All the ingredients of an epic fire tornado

are now in place.

This was ranked as an E.F.-3, Enhanced Fujita scale tornado.

I believe this is the strongest documented fire-induced tornado.

Temperatures reach 2,700 degrees Fahrenheit, 00:00:00.000.

Temperatures reach 2,700 degrees Fahrenheit,

hot enough to melt steel.

It lasts for 30 minutes.

We saw things like pipes wrapped around trees,

flipped-over cars,

power lines that were broken off

from 90-foot towers that were taken down.

The winds to do that are extreme.

A word redefined by megafires

as they grow in size, frequency, and impact.

But the destruction they create

makes it easy to overlook an important point:

Fire is an essential part of a natural cycle

that keeps a forest healthy.

What fire does is,

it essentially releases nutrients, precious nutrients,

into the ground

so that new plants can grow and thrive,

and it creates a cycle

where once plants grow enough,

essentially, they are setting the system up

for a future fire.

The concerted effort to stop that cycle of fire

began more than a century ago.

The modern fire story in the U.S.,

wildland fire story,

begins in 1910, really.

The spring of 1910 brings severe drought

to the northern Rockies.

In April, hot coals spewed from a chugging locomotive

spark fire in western Montana.

In short order,

there are hundreds of small fires burning there

and in Idaho.

As spring becomes summer,

the drought persists, the winds pick up,

and the fires grow larger.

3,000 men are on the front lines,

trying to beat back the flames.

There was an organization,

the U.S. Forest Service, barely five years old,

that was now charged with dealing with these large fires.

1910 overwhelmed the system completely.

Three-and-a-quarter million acres in the northern Rockies,

most of it concentrated in a two-day period

called the Big Blowup.

The Big Blowup is triggered

when hurricane-force winds turn those smaller fires

into several giant firestorms.

They leave a path of devastation,

charring an area the size of Connecticut.

78 firefighters are killed.

And the history and ecology of U.S. forests

would be forever changed.

The thinking was,

"We could have stopped these fires.

"If we'd had more men, more telephone lines,

"more lookout towers,

"we could have caught those fires early

and there would not have been a Big Blowup."

President Roosevelt's attack on the Depression began

with his emergency conservation project.

During the Great Depression,

Forest Service chief Ferdinand Silcox WEBVTT 00:00:00.000.

Forest Service chief Ferdinand Silcox

deploys New Deal workers and money

to reshape the national forests

with roads, lookout towers, and phone lines.

Then, in 1935,

he announces something called the 10:00 a.m. policy.

It meant that by 10:00

the morning following the report of a fire,

you would have that fire controlled.

So if you found the fire at 10:00 p.m. Tuesday night,

you would have it controlled by 10:00 a.m. Wednesday morning.

If you failed Wednesday morning,

then you'd plan to have it controlled

by 10:00 a.m. Thursday morning.

Washington gives the Forest Service the money

to make the 10:00 a.m. policy a reality.

So you develop smoke-jumpers.

You develop organized crews.

You put in trails.

"We're going beat back the fire menace."

Over time, the American public becomes enamored

with the heroic narrative of smoke-jumpers and hotshots,

while being fed a steady diet

of public service announcements from Smokey Bear.

Remember, only you can prevent forest fires.

The message seems clear:

Forest fires are the enemy,

to be avoided or attacked at all costs.

All of the science,

all of the officials,

are very keen to eliminate fire.

They see no purpose to it.

It's dangerous, it's a nuisance.

"We will find a modern alternative."

But the war on fire creates some unforeseen consequences.

With the natural cycle interrupted,

forests become dense with fuel for fires.

So in the 1960s and '70s,

the seeds of a new kind of thinking begin to take root.

It was realized in 1978 or so

that we weren't going to win by suppressing fire.

We were having more fires,

no matter how much money we spent,

no matter how much technology we threw at the fires.

The 10:00 a.m. policy was abandoned

and a new fire policy was introduced,

where fire was supposed to be incorporated more integrally

into wildland management.

Instead of all-out war,

it is a more nuanced approach:

Prescribed burns encouraged;

Wildfires not attacked, but managed,

allowed to burn whenever and wherever possible.

But in the real world,

it proves much easier said than done.

It's hard to find a place

where the new policy isn't at odds

with a building boom in the forest.

In August 2018, a case in point in the Cascade Mountains,

90 miles east of Seattle.

The Cougar Creek Fire is ripping

through the Okanogan-Wenatchee National Forest.

The area is sparsely populated,

and the fire began with a lightning strike.

It might seem like the perfect place

to let a fire burn. WEBVTT 00:00:00.000

to let a fire burn.

But the fire has gotten very big, very quickly,

and it is heading toward the small communities

nestled in the forest.

So the man in charge really has no choice.

Morning, everybody.

He has to draw a line in the woods

and stop the fire from moving beyond it.

Today is going to be a busy fire day.

So I ask that mentally we be there

and be ready for that.

Noel Livingston is a veteran incident commander

for the U.S. Forest Service.

He first started fighting fires 36 years ago.

How do we manage this fire problem that we have?

Because we have a fire problem.

We have landscapes that are out of sync,

and we have people living in those same landscapes.

The easy solution of, "Well, let's just let it burn,"

isn't realistic.

Today, nearly 100 million Americans have made the decision

to live in the woods,

what scientists call the wildland-urban interface.

We love these places,

and yet we're living with a certain amount of risk

that they will go up in flames.

We're literally putting homes in the line of fire.

There are hundreds of thousands of homes

that have been threatened over the last several decades

by wildfires,

and we expect that to go up.

Every firefighter here at Cougar Creek

knows the bitter irony:

Their success in the short term

might make the people nearby feel safe living here

and encourage even more building.

But it is a false sense of security.

Each time they stop a fire in its tracks,

fuel for the inevitable builds up,

and fires are more likely to become megafires.

Because we've excluded fire

for the past hundred years or so,

particularly in heavily wooded stands,

we're getting more of a continuous, high-intensity event

in those types of stands.

This ups the ante for firefighters

already doing very risky work.

As the fire grows in strength,

safety officer Jennifer Rabuck is on a scouting mission

near the fire line.

She aims to strike a balance between saving homes

and protecting firefighters' lives.

This is our primary containment line

that we're walking on.

The fire is off to our right.

Ideally, we'd like to hold this line.

Hot embers from the wildfire,

launched and carried by the wind,

are flying overhead, landing in what amounts to kindling.

You look at some of this,

it's all dry and dead,

and it just flakes off in your fingers.

There's nothing in here

that has got any sort of resistance to take.

If an ember lands in here,

this piece of wood is going to catch fire.

The dead, dry wood is where spot fires start,

but not where they end.

With the temperature high and the humidity so low, WEBVTT 00:00:00.000.

With the temperature high and the humidity so low,

everything here is dehydrated and highly flammable.

This is what we call tree torching

or even group torching.

Single tree would be one,

group torching would be pockets of trees.

When it's torching, it starts out on the bottom.

And as those flames grow, it's sending that heat up

into the live part of the tree, the green part of the tree,

preheating it,

so it's more receptive to that build-up and build-up,

and it reaches a certain combustion point,

where the entire tree will go up.

And you can see the ember wash coming off of those,

and you can see how far it's going over the ridge.

This is a living tree that's gone up?

This is a living tree.

What goes through your mind when you see this?

Right now I'm wondering if we're in a good spot.

The Cougar Creek Fire will burn more than 42,000 acres

before it stops spreading.

But no structures are damaged.

Another victory for the nation's wildfire fighting force.

They succeed 97% of the time.

A century of excluding fire

has created some unhealthy, dangerous forests

all over the United States.

But how best to allow forests, fire, and people to coexist?

Fire ecologist Sharon Hood is testing some alternatives

in western Montana.

Got the pith.

Nice.

This 30-acre plot is part of a long-term study

to see if there's a better way to manage our forests.

It hasn't burned in 100 years,

and it is filled with fuel for a fire.

It's hard just to plow through, much less do their work.

You basically can't see through it,

and when you're trying to walk through it,

you're weaving through very small trees,

you're stepping over a lot of logs.

It's the density that strikes me.

The dead and small trees and the shrubs

are the ingredients, the fuel, for bigger, more intense fires.

This forest is a tinderbox...

A consequence of a misguided forest management philosophy.

Our ponderosa pine forests

evolved with very frequent fires...

On average, every seven years.

So removing fire for 100 years

allows all these little seedlings to get established.

If fires were coming through here routinely,

they would kill those seedlings, creating open conditions.

And she has the scientific proof in the plot next door,

where they thinned out the trees in 2001, WEBVTT 00:00:00.000

where they thinned out the trees in 2001,

then started a prescribed burn in 2002.

You're looking at this open ponderosa pine forest

16 years later.

The thin-and-burn forest is all open space.

There's not a lot of fuels, and you see the larger trees.

Back in her lab in Missoula,

Sharon and her team carefully slice and analyze

the core samples

from the thinned and burned parcel.

The tree rings tell a story, if you know how to read them.

Here we have a close-up of a tree core,

and each light and dark band is one year's worth of growth.

And you can see, between 1990 and 2000, in this section,

you've got narrow growth rings.

Narrow rings mean less growth,

nature's record of how the trees were faring

before the experiment began.

And then, here in 2001,

there was a thinning, where we cut about half the trees,

and then in 2002, there was a prescribed burn.

And you can start seeing really fat growth rings after that.

A forest that is more open

and trees that are larger and healthier.

Thinning and controlled burning clearly works.

But is it practical beyond an experiment?

This type of treatment that you see here is scalable.

There's no one-size-fits-all,

but thinning is a major tool that we have

to be able to re-introduce fire in a safer way.

It isn't the answer in every forest landscape.

And prescribed burning faces a lot of opposition,

ironically, from the people most in harm's way,

worried about changing their view

or breathing the smoke.

When we put a little bit of smoke in the air

under prescribed fire,

sometimes it can meet a lot of resistance from the public.

There have been some prescribed burns

that were supposed to be small forest treatments,

and then a gust of wind came at the wrong time

and turned that prescribed burn into a wildfire.

And what about the expense?

Thinning and burning can cost about $1,000 an acre,

and it's not a one-time fix.

But compared to the cost of a megafire,

maybe it's an ounce of prevention.

I think by now,

people who live in the forest or near the forest recognize

that there's going to be a fire now

or there's going to be a fire later,

and you can have it under controlled conditions,

when you can go away for the weekend,

or you can be running for your life

watching your house burn down.

Humans have created the megafire monster,

but enlightened forest management alone

won't stop the infernos.

Because there is another factor at play,

also with our fingerprint... WEBVTT 00:00:00.000

also with our fingerprint...

Climate change.

The Camp Fire has broken records,

and yet it is only one of three major incidents

in California right now.

We've been going

from fire to fire to fire,

and every time we see it,

it's, like, "That, that's unbelievable.

"That's unbelievable.

I can't, can't believe we're seeing this."

And in the land of endless summers,

there is now an endless fire season.

We're in November... this is...

This is not historically when we would see fires still occurring.

It would be closer to the hotter part of the summer,

but they're, they're lasting into December now.

So it's, it's a fire year.

There's no fire season.

A fire year,

year after year after year.

What role do rising temperatures

and changing precipitation patterns

play in this trend?

In California, the record wildfires occur

after a historic six-year drought.

Climate change

is taking a pretty bad drought

and actually causing it to be

on par with the biggest droughts over the last millennium.

To better understand this link between climate and fire,

paleoecologist Cathy Whitlock spends a lot of time

in Yellowstone National Park.

It's a nearly pristine ecosystem

where we can really see these things going on.

This is Blacktail Pond.

The layers of mud beneath this ancient lake bed

have their own story to tell, going way back in time.

Lakes are great repositories of environmental information.

Pollen grains land on the surface of the lake,

and they get buried in the sediment.

Charcoal from fires gets carried in the air

and then sinks to the bottom.

And those sediments are undisturbed,

and so you get a continuous record of environmental history.

One, two, three.

Keep it straight, keep it vertical.

All right.

So let's pull it up.

Let it drain, turn it sideways.

Okay, now we're going to extrude.

Here it comes.

Nice!

Whoo!

Using two types of clues,

she can learn a lot about the ancient landscape.

Pollen tells us about the plants that are growing here,

and the vegetation is one of our best indicators

of what the climate was.

So we can use the pollen record to reconstruct past climate,

and then we can compare it with the charcoal record of fires

to see how periods of fire relate

to periods of climate change.

The sediment at Blacktail Pond

allows Cathy to look back 15,000 years,

when the glaciers from the last ice age retreated

from this area.

Back in her laboratory, WEBVTT 00:00:00.000.

Back in her laboratory,

Cathy slices the cores in half

and begins to take a closer look.

There's a lot going on at this time period in this lake.

The light-colored layers are calcium carbonate-rich.

They probably were deposited by algae

that were producing this calcium carbonate,

and when that happens,

usually, it happens because the lake's a little bit warmer.

The dark layers,

I'm seeing little blips of what look like charcoal to me.

But I suspect there's going to be a lot of charcoal

all the way through this core.

We just have to look under a microscope to find it.

After they chemically treat and sift sediment from the core,

they can clearly identify and tally the charcoal

and the pollen.

I'm seeing some large pine pollens.

They kind of look like Mickey Mouse hats.

And some of them, like that one, is a lodgepole pine, for sure.

She has documented a long relationship

between fire and temperatures.

Over the past 7,500 years,

fire activity closely correlates with the climate.

As temperatures cooled,

fire activity gradually decreased.

But as humans have warmed the planet in the last century,

fire frequency has dramatically increased.

During the warm, dry, windy summer of 1988,

800,000 acres,

one third of Yellowstone Park,

burned.

Her analysis shows

it was one of the largest fire seasons here

in the past 6,000 years.

If current temperature trends continue,

fires of that magnitude

will likely be more frequent in the future.

I think we're moving into uncharted territory.

We're seeing warming at rapid rates,

we're seeing extreme fire events.

We're seeing things that we just haven't seen in the past,

and that's my big concern.

Cory, do you have all the vials?

Ecologist Monica Turner has the same concern.

She and her team

study Yellowstone's breathtaking lodgepole pine forests.

In Yellowstone,

what I do is try to understand

how fires affect the forest

and then how the forest recovers.

The fires here in 1988

were part of the normal, 100-to-300-year burn cycle

for lodgepole pines.

Although the fires were big and severe,

the forests of Yellowstone recovered

in spectacular fashion.

But in 2000 and again in 2016,

new fires hit some of the same areas that burned in '88.

Monica wonders if climate change is making it hard

for the forest to bounce back once again.

So that's something like 104 degrees Fahrenheit...

Whoa.

Just below the surface here.

That's hot.

Too much heat, too little shade. WEBVTT 00:00:00.000.

Too much heat, too little shade.

And what happens when forests burn again so soon,

before there is time to recover?

To find out, they systematically count and measure

tree seedlings.

D8 is dead.

And they determine how far they travel.

What we are hoping to find out here is,

"Will they germinate?

Are the conditions suitable for them to grow?"

In this plot,

where only 16 years separate two fires,

young trees are completely destroyed.

Only stumps remain,

and there is on average a 60% reduction

in the number of tree seedlings.

More frequent, more severe fires and warmer temperatures

mean new generations of trees will have a much harder time

taking root.

We are now questioning

how the frequency and the severity of fires

may overcome the ability of the forests to recover.

If we have future fires that happen every 15 years,

I don't know.

Fire may be integral to the evolution of forests,

but the scale and frequency of today's megafires

appear to be something new.

The landscape is changing fast,

a symptom of climate change that is more sudden than most.

Going into the future,

I think we're going to have more fires.

And if we continue to have more fires,

it will gradually shift the composition of the forests.

In some places, we may lose forest

and get more grassland.

The Camp Fire is still burning,

but in Paradise, embers are starting to cool.

George Gold is headed through town

on his way to Magalia, just to the north.

He already knows his house is destroyed,

but what happened to the sports car

that he left a mile away in a parking lot?

Finding out is his main goal today.

There is my car!

I see my car!

It's there.

Can you believe it?

My Miata is alive.

A-ha, she lives!

It's time to see

if there's anything worth salvaging at home.

This was my neighborhood, and there's nothing left.

There's, there's no neighborhood here.

There's just debris.

I mean, it was gorgeous here, just gorgeous.

Peaceful, quiet.

My shed's there,

so I can do my gardening.

And this is my front door, right here.

187507, 00:00:00.000.

Open the door.

I mean, I never considered myself a materialistic person.

I mean, if you went in my house, you would say,

"Gee, you're kind of living a spartan life," right?

No fancy stuff, just basic stuff.

But the stuff I had, I loved it, right?

Every time I walked in the door, I thought,

"Wow, this is my house.

I've made it, I'm in heaven."

And I had all these tool boxes.

You know, I spent 30 years gathering tools.

Here we go.

They may live again.

Maybe.

I think not.

It's really hard.

I don't know what to do... I don't know what to think.

I've never experienced anything like this.

I don't know what to think, I don't know what to do,

I don't know what to feel.

I don't know... I'm no youngster anymore.

I don't know if I'll ever recover.

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