Nova (1974–…): Season 46, Episode 8 - Inside the Megafire - full transcript

Scientists try to determine the cause for the increasing megafire threat by exploring the physics of fire, how firestorms move and travel, and by analyzing aerial drone and satellite data to catch fires before they start.

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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"

♪♪

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

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

Oh, 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

Oh, 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

Oh, 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

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, "Oh, how nice"

I open the door, and it's windy

♪♪

I look up, and it's dark

I thought,
"Oh, 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,
"Oh, 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

Oh, 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

Oh, 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

Oh, 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,

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

"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

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

Engine 83 Here

36-31-Charlie Here

Engine 25 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

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,

I... I 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

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,

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

♪♪

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

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

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,

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

Oh, 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

Oh, 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,

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...

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,

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

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

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,

"Oh, 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

♪♪

♪♪