♪ [Beep] ♪ Man: My name is Dimitrios Theodorakakos.

I'm a trail and marathon runner.

I live and train in Athens.

♪ During summer in Athens, is extremely difficult to run during the day.

The temperatures are extremely high, so we try either to run very early in the morning or very late at night.

Narrator: Summer temperatures in Athens regularly top 100 degrees Fahrenheit.

Climate change will drive them up even further.

Highs of 110 degrees are expected in the next 30 years.

Dimitrios: I feel, every year, it becomes more and more difficult.

When the temperatures are really high, I sweat a lot, which means I lose maybe one liter and a half every hour of running... [Exhales] so I dehydrate all the time, every day.

♪ Narrator: The higher the mercury rises, the more dangerous it becomes for athletes to push themselves to the limit.

♪ Dimitrios: Scientists say that because of climate change, by 2085, only 35 cities around the world will be capable of hosting the Summer Olympic Games.

♪ Unfortunately, my city, Athens, will not be one of them.

Narrator: The home of the modern Olympics is expected to exceed the safe temperature limit for elite endurance events, as will many other former Olympic cities.

♪ Dimitrios: All athletes dream to compete at the Olympic Games and represent their country.

♪ It's really sad for Greek athletes that they will not have this opportunity.

Narrator: It's a reminder of how rising temperatures impact us all in the most unexpected ways.

Dimitrios: Climate change does not affect only running, but also everything to do with our way of life.

♪ Narrator: In this epic new series, filmed over 3 years, we explore the extremes... on all 7 continents... [Man shouts in foreign language] Narrator: meeting people standing in the face of change and discovering how science... Whoa!

Narrator: nature... Oh, my gosh.

Narrator: and Indigenous knowledge can prepare us for a hotter world.

In this episode, we find out how rising heat, drought... and fire... Man on radio: We have heavy fire activity on our right.

Narrator: are reshaping our dynamic planet.

Narrator: And we reveal the people racing to turn the tide.

♪ [Woman vocalizing] Narrator: Two degrees Fahrenheit.

Doesn't sound like much... but this increase in average temperatures over the last century or so has global implications.

While the effects of this warming on the natural world can sometimes seem gradual or remote, the impact of extra heat on our lives is immediate and hard to miss.

[Distant car horns honking] Heatwaves now cause over 350,000 deaths a year.

[Children chattering and laughing] Narrator: People in urban areas and places with high humidity are particularly vulnerable, especially in the poorest nations, least able to cope.

But the most obvious consequence of global heating is the most terrifying of all.

Man on radio: We have heavy fire activity on our right, coming down [indistinct] Road, and numerous spot fires there on our left, coming down the road.

Man 2 on radio: OK, copy that.

[Indistinct] Narrator: For firefighters, the rules have changed, and the stakes have never been so high.

♪ Man: My first couple days here were exciting.

I was a new rookie.

I was, you know, like a sponge, ready to learn from the old guys, and now I am one of those guys.

But the thing that has not changed is I still love coming to work every day.

Narrator: Patrick Kramer has been a firefighter for 19 years, long enough to see how the changing climate is making wildfires worse than ever.

Patrick: Some of the biggest changes we've seen in wildfire is they're growing, they're-- they're burning more acreage, they're burning hotter.

[Alarm blaring] There really isn't a fire season anymore.

It's year-round, especially in Colorado.

Some of the biggest fires I personally have been on have been in October, November, and December.

[Engine turns over] Narrator: In 2021, Colorado had its most destructive wildfire in history, and it happened when no one was expecting it.

[Brakes hiss] [Siren blaring] Patrick: In the Marshall Fire, it was a wakeup call.

It's December 30th.

There's snow on the ground.

It's probably ambient temperature of 25 degrees outside.

We saw the fire coming from the west, and within less than 10 to 15 minutes, the first home in the cul-de-sac was burning... and we're hearing on the radio of multiple structures burning.

♪ The best way I can describe it was probably evil.

If there was a fire that was evil, this was the one.

The whole street's on fire.

Man: Water!

Patrick: The winds, the grit, the heat, the smoke was something I've never experienced before.

There goes another neighborhood.

It doesn't discriminate.

It doesn't matter if it's burning into a shack or a $2 million mountain home.

It doesn't care.

Mother Nature wins every single time.

[Distant sirens blaring] ♪ Narrator: In just 10 hours, this winter wildfire killed two people, destroyed over a thousand homes, and burned 6,000 acres of land.

[Sirens continue] ♪ Across America, 7 million acres go up in flames each year, while globally, wildfires burn over a billion acres of land annually.

That adds as much CO2 to the atmosphere as all of Russia's emissions for a year and pollutes the air for hundreds of millions of people.

But, in some places, preventing fire is the worst policy of all.

♪ Woman: Grandfather, Grandmother, see us.

Here are your children, your grandchildren, and your great-grandchildren.

Guide our hands as we bring fire back to the land to restore the ecosystem, to restore our food sources and our medicinal sources.

[Speaking Native language] [Singing in Native language] Woman, voice-over: As Native people, everything that you do had to do with prayer, and so we're sending up prayer to acknowledge that we're bringing fire, we come in a good way, you know, we want to bring balance to our land, to take our place as stewards of the land, and to take care of it and restore it to health.

Narrator: These forests are cared for by California's Yurok Nation.

Margo: You guys can go ahead and get your fire on.

Ha ha ha ha!

Narrator: Since the time of Spanish colonial rule, authorities here have outlawed the Indigenous community's traditional burning practices.

That's only made matters worse.

Now the dense undergrowth is like a tinderbox awaiting a spark.

As California sets new temperature records, the danger of uncontrollable wildfires increases.

Margo: When you're doing a burn, and you're reducing the amount of this understory fuel, then the fire has less to feed it, it has less food.

Wow.

We're gonna see some activity over there.

Narrator: Prescribed burns like this are conducted by a large team, and only when weather conditions allow.

They're like small, controlled burn lines, which deprive the fire of fuel, helping to keep it under control.

What could turn into a terrifying megafire next summer is instead a force for good.

[Margo laughs] Margo, voice-over: Fire is meant to be a natural part of the ecosystem.

These lands, they evolved with fire.

They depend on fire to be healthy, so when it's all crowded out with brush, like you see now, all that brush is sucking up water.

It's like if you had a cup of water and there was 20 straws in it, sucking out of it, how long is it gonna last?

And so the creeks start to disappear, and the creeks feed the river, which have fish in them, and if it doesn't have enough water, the water gets too warm, and the fish, they literally suffocate to death.

♪ Narrator: Fires like this encourage biodiversity, returning the forest to a time before loggers planted it with swathes of fast-growing fir trees.

♪ [Hoots] Look at that!

Heh!

Margo, voice-over: We was just full of joy to see them going down because they really suck up the water.

They're like a giant straw on the cup.

Ha ha ha ha!

♪ Margo: It's really hard to describe it, but it is certainly a great deal of joy.

Ha ha ha ha!

It just makes me laugh with happiness.

Ha ha ha ha!

It's very exciting.

[Generator humming] OK, we do have new wicks, so... Narrator: Margo's enthusiasm has rubbed off on son-in-law Talon.

Talon: I'm gonna go observe the fire for a little bit.

[Indistinct chatter] I love fire.

I feel like I've built a-- really an amazing relationship with it, and when we're out there burning, I know it's-- it's truly a way to maintain balance for Mother Earth and--and for all of us.

♪ Narrator: The Yurok nation nearly lost their traditional fire knowledge, but Talon's kids are absorbing it firsthand from an early age.

Margo: Whew!

How's Gram's boy, huh?

How's Gram's boy?

Margo, voice-over: What we started will carry on into generations, into the future, like, our vision for it will not be completed in our lifetime, by far, and so it's important to start passing the information down to the next generation.

Talon, voice-over: My two boys are my world.

I've just been kind of blessed with this fire, you know, in more recent years of my life, but it's something that they'll get to see, they have seen since--since babies, and they just smile so big and--and they're like, "Look at the big flames," you know?

Margo, voice-over: They should be introduced to fire as babies, and so that's what we do.

It feels really good to know that we're restoring our lands and that with restoration of the land comes restoration of the people.

It brings pride to the people that are engaging with fire.

♪ [Man speaking indistinctly over radio] ♪ Talon: It can be burning pretty deep under there.

That's where you'll still see smoke.

Sometimes it's just steam, too.

[Indistinct chatter over radio] Talon, voice-over: When I first moved here, everywhere else was super-brushy, but with bringing the fire back to the land, I've seen that significantly change.

It's--it's awesome.

In this last year, I've-- I've seen more deer--heh!-- in the daytime than I've seen in the last 5 to 10 years past.

♪ Margo: Whoo!

Ha ha ha ha!

Margo, voice-over: I want my children and grandchildren and great-grandchildren and so on to have a good place to live.

I want them to know who they are as Native people, to have a healthy river to swim in, to eat salmon, to hike the hills.

I can't change the world, but I can change this small place where we live, and then share--share that information with other people.

♪ Narrator: The Yurok are restoring balance to the ecosystem and reducing the risk of major forest fires in the future.

But wildfire is only one of many challenges in a warming world.

♪ Woman: We went through, like, a 7-year drought.

There was absolutely no rain.

You would see carcasses of dead animals all over the place.

[Goat bleats] ♪ Woman, voice-over: It was so dry.

It was bone-dry.

There was absolutely nothing.

Absolutely nothing.

♪ [Shannon speaking Native language] Man: Yeah.

We need more, still.

Definitely not enough.

Yeah, not enough.

Yeah, not enough.

Can you quickly stop here, Herman?

I see some fresh tracks.

Narrator: Life here became even harder when a herd of elephants moved into the area, looking for water.

Come check this out.

Saw something?

Yeah.

[Car door closes] It looks quite fresh, going this way.

All right.

Oh, they're going this direction.

Let me check for more tracks.

Yeah.

Have a look.

Let's see.

Let's see.

Did you find some?

I think it's today's.

OK. Yeah.

Couple of hours back.

[Vehicle rumbling] Shannon, voice-over: People had no idea how to live with elephants.

And then, all of a sudden, there were elephants everywhere, you know, and people's lives changed.

♪ [Elephant grunts] Narrator: Small groups of desert elephants have roamed around Namibia for thousands of years.

They've adapted to the extreme conditions, making them distinct from other African elephants.

Their wider feet make it easier for them to walk on sand.

They can cover up to 90 miles a day seeking water, which they can smell from 12 miles away.

Their dung disperses seeds, which encourages biodiversity, creating a more climate-resilient environment, better able to withstand drought.

But, as temperatures soar and droughts last longer, their search for food and water brings them into deadly conflict with humans.

Shannon: The ana tree is a really large, thorny tree, and it has seed pods about this size.

They curl a bit, and they're very nutritious.

It's like a delicacy for the elephants.

They love them.

Elephants love them.

[Pod crunching] Narrator: The problem is that people want the same seed pods to feed to their livestock.

Climate change ratchets up the tension.

Shannon: You find people collecting pods in an area where the elephants roam freely, and it's--can be a dangerous situation.

Narrator: It's Shannon's job to teach people how to safely coexist with the elephants.

There he is.

There we go.

That's the big boy.

Shannon, voice-over: My uncle got killed by an elephant just outside our family house.

He went to visit his friend, so he'd spent the whole afternoon there... [Elephant grunts] Shannon: walked back home late at night.

♪ Shannon, voice-over: And then he walked right into the elephants.

I think out of fear and panic, they turned to run, and the elephant also startled, chased them, and he fell, and then the elephant got him.

Smashed him to pieces, basically.

♪ I don't want people to experience the same fate my uncle experienced.

You know, had he had the knowledge that I give to people now, he probably wouldn't have... died the way he died.

♪ ♪ Shannon, voice-over: It's not easy, you know, doing this job and having a family.

Oh, well, well.

Shannon, voice-over: I want my children to grow up and see what I've done, you know.

I want to leave a worthy legacy, and I want her to love elephants.

[Baby grunting] Woman: How do you feel, going back to work?

I'm a little sad-- heh!--leaving, leaving you guys, too, but it's fine, and, well, I'm happy she's with you.

Yeah, fine.

Shannon, voice-over: Some sacrifices have to be made, but they're really small, compared to what I'm trying to achieve.

[Distant goat bleats] Bye, guys.

Bye.

[Door closes] ♪ Shannon: People are poor out here, like, people are really struggling out here.

They are really struggling, you know, and then you also have to think about elephants destroying your house.

And then everybody's like, "Save the elephant."

♪ People need help, too.

♪ Hello?

[Sighs] OK, OK. You know, every time I come out to the machete communities, I actually have to prepare myself, like, psychologically, because people here don't really like elephants.

It's a whole series of events that have unfolded since the death of my uncle, so I'm a little worried about that.

I just don't know how he's gonna react, you know?

Just have to be prepared for anything.

♪ [Shannon sighs] Shannon, voice-over: He's really angry, and I'm just listening to him.

I'm just letting him just blow some steam.

He's mad, but he's not mad at me.

That I know.

Shannon: And then we hear the elephant.

[Distant trumpeting] Yes, it's the elephant.

The elephant is there I'm talking about.

The thing that I'm talking, that is present now.

Shannon, voice-over: I'm like, "It's right here, actually?"

He's like, "Yeah, I'm talking about an elephant that's here right now!"

[Giggling] [Chuckles] ♪ ♪ Shannon, voice-over: He couldn't believe that this is the same elephant that he saw a couple of minutes ago and he ran from.

That was the realization, in that moment, that the animal that he's so scared of is actually also scared of him.

Shannon: And then after that, as we were driving back, I could have sworn we were friends.

Narrator: With the tension gone, Shannon can offer some practical help.

Narrator: Mixed with elephant dung, the chili becomes a powerful repellent.

[Indistinct] OK. Shannon, voice-over: You cannot save the elephants without saving the people.

I love the elephants, but I equally love the people that live with these elephants.

[Chicken clucks] Finding a solution for both parties-- that's the real solution.

♪ [Elephant grunts] Shannon: In my village, after my uncle was killed, they actually built an elephant drinking dam, which is far from human settlements and where they can peacefully drink water.

And honestly, elephants don't come to people's homes anymore--they don't-- and that's the truth.

It's my hope for the future that my children will grow up in a community where there's, like, a--[sighs]-- a peaceful coexistence between elephants and people, yeah.

♪ Narrator: Coexistence benefits us all... as what's good for one species is often good for another.

♪ This was the site of a major wildfire in 2021.

The forest still hasn't recovered.

♪ Woman: Within this fire scar, there were really big patches of really high-intensity burning.

♪ Walking through this landscape, it smells like campfire still.

It smells like burnt wood, and it's creepy how quiet it is.

You don't hear the insects buzzing around.

All you can hear is the wind, sort of passing through these bare-branched trees.

Narrator: Emily and research assistant Keitreice are looking for life in this fire-ravaged landscape.

[Drone buzzing] Emily: We're looking for that oasis patch.

Get him up over those trees.

There it is.

Keitreice: Oh, look at all that water.

Wow.

That is just... exactly what we were looking for.

♪ Emily: Oh, yeah, I see some chewed stumps up ahead.

Pretty good cuts... some woodchips... and this one-- classic beavers.

They've almost got it in the water, not quite.

Ha!

Emily, voice-over: I study beavers and the way that they change the landscape to make it drought- and fire-resistant.

Almost done.

Emily, voice-over: I go visit these pockets and figure out, "Why didn't this burn?

Are there beavers there?"

♪ Oh, I think I see what we're looking for.

Keitreice, voice-over: You go over all this really fire-scar, burned area, and then you just see water.

Emily: Oh, yeah, here it is.

Keitreice, voice-over: And, like, a lot of it--ha ha!-- untouched, un... unscathed, just this really green, suddenly, and then you see the dams through it and it's just really--I don't know.

It makes me happy.

Ha ha!

Keitreice: Whoa.

Oh, yeah.

Definitely... a beaver dam.

Emily, voice-over: This is definitely beaver habitat.

That's confirmed.

They've just packed mud on, and it's got to have been put there in the last week, so I know the beavers are still here.

This looks like it was just packed on.

Oh, yeah, and then back here.

Look.

This is one of their paths.

Oh, yeah.

Must go waddling...

They're, like... up and down right there.

freshly building on this.

Totally.

Emily, voice-over: Beavers build dams.

That's their most sort of classic example of their engineering, and that's what creates the big pond they live in.

So they go through all this work, changing the landscape so that they can be safe... and the end result of that is that when you have droughts come through the landscape, their ponds stay green.

And then, when a fire comes through the landscape, it's the same thing; it's just so wet, it's not gonna burn.

Evolution has taught them how to make incredibly stable and resilient habitats so that they can survive even pretty destructive shifts in climate.

Narrator: The beavers' ecosystem engineering benefits many creatures.

[Buzzing] Keitreice, voice-over: You get to this oasis the beavers created, and you hear birds and you see all these animals that survive, thanks to the beavers.

[Hawk screeches] It's really incredible.

Emily: This patch, it was great during the fire, but after fire, it's almost, like, this nucleus for life to re-expand out, back into the landscape.

♪ Emily: All right, do you want to place the camera or be the fake beaver that I aim it at?

I will be the fake beaver.

OK, so you... Narrator: The beavers are wary of strange sounds.

Trail cams will catch them undisturbed.

Further?

Um, I think you're probably good there.

Emily, voice-over: Keitreice, like many of my students, have not seen beavers before in real life.

To see them, you kind of have to make it a whole trip and go out and wait at night, and so, coming up here, I'm really hoping she gets to see 'em in person.

♪ [Whispering] ♪ ♪ [Giggles] Keitreice: I've been studying beavers for two years, and this is the first time I've seen one in person, and I've seen a really big one, at least 65 pounds.

I feel really lucky to see that.

Heh!

♪ [Music fades] [Bird screeches] ♪ Emily, voice-over: Checking my trail cams is a little bit like opening up a present, and you don't know what's gonna be inside and it's probably gonna be cool, but you're not 100% sure.

All right, let's see what our first image was.

A beaver?

Oh, look at that.

[Giggles] Beaver.

He's perfect.

Aw.

Look at him.

He's so cute.

Just walking up to the camera.

Emily, voice-over: There has been a lot more animal activity here than just the beavers.

Let's see.

Who else?

What's in this one?

Bobcat?

Oh, wow, look at its fur.

They just take... And his little tail.

same path the beavers did.

Then, who's that?

Oh, a possum.

Possum.

It's a sweet little one.

Wow, there's just so much going on here.

Plenty of beavers, but everything else, too.

There's the deer, possums, the skunks, the rabbit, the raccoon, the mouse, the-- I mean, everything out there, so much.

Ha ha!

And they're just going about their normal lives like this fire didn't even happen.

No.

It's great to see.

I mean, everything is just doing fine here.

It's really healthy.

It's beautiful.

I'm glad we came to this site.

Me, too.

♪ Emily: It's almost like you wouldn't believe it if someone just told you, like, "Hey, did you know that there's "this patch that totally didn't burn during the wildfire?

And by the way, a 75-pound rodent made it."

♪ It's very inspiring.

I think climate change and fire and drought, they're all very depressing topics to be involved in... but when I see beavers and when I see what they're doing to the landscape, it makes me smile and it gives me hope.

♪ Narrator: As our carbon emissions alter the climate and the earth heats up, inhabitants of the natural world are forced to adapt.

In the mountains, plants and animals are gradually moving to higher altitudes, seeking cooler conditions.

Research shows that for every degree Fahrenheit that the temperature goes up, Alpine species shift their altitude range about 150 feet uphill.

Elsewhere in nature, animals shift their latitude instead.

In the oceans, fish like bluefin tuna are moving poleward and into deeper, cooler water.

On land, regular bird counts by the Audubon Society show that many North American birds are moving northward.

Purple finches are spending their winters more than 400 miles farther north than they did 40 years ago... [Chirping] but the consequences of species moving into new areas can be severe.

♪ In North America, something is killing nearly as many trees as wildfires.

Hundreds of millions of acres of healthy green pines turn red... and within a couple of years, they're dead.

♪ Woman: The forest is definitely changing.

It's sad to see, you know, millions upon millions of dead trees.

♪ Narrator: As the climate changes, a deadly pest is moving in.

♪ Antonia: Trees here are naïve to this new threat.

They have no defense.

Narrator: Boreal forests like this cover 17% of the planet, storing twice as much carbon per acre as the Amazon.

But they are under threat from an almost microscopic enemy... ♪ the mountain pine beetle.

Winters were previously too cold for the beetles to live here, but as the region heats up, they're moving north.

♪ Antonia tracks the beetles as they spread into Alberta's pristine forests.

Antonia: Now we're having these hyperepidemics, where large areas of trees are being killed.

It threatens not only timber and forestry, it also threatens the ecosystems.

Narrator: There's one way to know for sure if a tree has been infected.

[Hammer tapping] Antonia: The female entered the tree around here.

She started to mine vertically.

I definitely see eggs.

Oh, there she is!

I caught her.

She's right there.

It's kind of mind-blowing that something as small as a grain of rice is able to kill millions of hectares of forest.

Narrator: The life cycle of mountain pine beetles is driven by temperature.

The warmer the winters, the more larvae survive.

But the trees do have one defense mechanism.

Antonia: Trees are not completely vulnerable to mountain pine beetle.

♪ One of the things that they use is pitch, or sap, that sticky stuff that you see coming out of a tree.

♪ They use this to physically remove the beetle from the tree.

And the beetle gets stuck, and you'll see it drown in that pitch.

Narrator: A few beetles, the trees can handle, but there is strength in numbers.

The beetles release chemicals called pheromones, allowing them to communicate with each other.

Antonia: They're kind of like party pheromones, to call all their friends to the tree.

They mass-attack and they all pile on the tree and are able to overcome the tree's immune system.

Narrator: Many will drown, but hundreds more will succeed.

This tree is toast.

The tree is going to eventually die.

It just doesn't know it yet.

Narrator: But the beetles have a weakness that Antonia can exploit.

If too many lay eggs in the same tree, there won't be enough food for their larvae, so they produce a different pheromone, signaling that the party's over and the tree is full.

Antonia: We're actually able to hack the beetles' communication system by synthesizing their "tree's full" pheromones and stapling it to trees.

Narrator: It's only a small-scale solution, but along with efforts to diversify tree species, it will help make the forest more resilient.

Millions of dead pines are easy to see, but some potentially devastating impacts of global warming are hidden in plain sight.

As the world heats up, bees are emerging earlier in the spring.

[Bees buzzing] Sometimes they find a world without enough food because flowering is primarily controlled by the length of the day, rather than the temperature.

[Bee buzzing] Many bees are already in steep decline, so additional challenges push them closer to extinction.

That affects us all.

Around a third of global food production depends on pollinators.

Over 20,000 species of bees, butterflies, beetles, and birds play a crucial role.

Protecting the biodiversity of the natural systems they rely on will help them adapt to a warming world.

♪ Each decade since the 1980s has been warmer than the last, with all the hottest years on record happening since 2015.

In places already struggling with tree loss and soil erosion, the growing scale of the problem requires extraordinary solutions.

♪ ♪ Narrator: As trees grow, they release water into the air, keeping the air cooler and creating rainfall.

Narrator: With fewer trees, the land is increasingly vulnerable to the rising heat and dries out quicker than ever before.

♪ Narrator: As the Sahel region gets drier and the land degrades, the Sahara Desert to the north is expanding, displacing many of the 100 million people that live on its margins.

Those who contribute least to global emissions often suffer the most.

[Distant dogs barking] Thousands of young people leave on perilous journeys to Europe in search of a better life.

Those that remain face the challenge of a hotter, drier climate.

[Birds chirping] Narrator: Malick's village suffers from soil loss and crippling drought.

It's very different from how it was when his father was young.

Narrator: Despite the scale of the challenge, Malick is determined to make a difference.

♪ He's joined forces with Sergeant Badji, working on a solution that provides hope for the future.

♪ Narrator: The whole community is involved, with local women leading the project.

♪ [Overlapping chatter] Narrator: This tree-planting effort is just one small part of a much bigger project known as the Great Green Wall, a 4,300-mile belt of vegetation stretching across Africa.

The trees create their own microclimate, providing shade and releasing moisture into the air.

As they grow, their roots bind the soil, helping protect land and livelihoods threatened by the changing climate.

Narrator: The Great Green Wall is one of the biggest environmental engineering projects in human history.

It fuses agricultural science... with local knowledge.

Narrator: 10 million people have been trained to nurture the trees.

Their work has the potential to improve the lives of millions more.

Narrator: It's early days, but a patchwork of productive land is slowly taking shape, 50 million acres and counting.

[Overlapping chatter] Narrator: Working with nature, the people of the Sahel are tackling the challenges posed by a warmer world and creating hope for the future.

♪ To order this program on DVD, Visit ShopPBS, or call 1-800-PLAY-PBS This program is also available on Amazon Prime Video ♪