This year, the world's best-known climate activist,
Greta Thunberg, turned 18.
People say a lot of things about me.
Greta... You know Greta?
CROWD JEERS AND BOOS
People call me a brat, an idiot.
And yet, for reasons I don't understand,
people listen when I talk.
CROWD CHEERS
You are listening to me right now.
CROWD CHANT: Greta! Greta! Greta!
But I don't want that.
I don't want you to listen to me.
I want you to listen to the science.
We are seeing a huge change in the temperature of the planet.
The science is very clear.
This is not someone else's problem. We all need to act now.
This series follows Greta on an extraordinary year
in her mission to fight climate change.
I've been going the whole way around the world the wrong way.
In 2019,
she took a year off school and set out to witness first-hand
the impact of global warming
with the world's leading climate experts...
This year we had the fastest melt rate
we've ever measured - six metres of ice down.
..and discover whether technology can help protect our future.
But we could store all the emissions we could potentially imagine.
We should be hopeful, but hope doesn't come from words.
Hope only comes from action.
Greta has taken her protest to the global stage.
World leaders are behaving like children,
so it falls on us to be the adults in the room.
But in a year when Covid-19 brought life to a standstill...
The risk level has risen. The coronavirus continues to spread.
I have contracted the coronavirus.
..can Greta convince a world reeling from one crisis...
..to finally face another?
Covid-19 has really given the world a tremendous opportunity to reset.
We're never getting out of here.
How we address the climate crisis
will determine what the future of life on Earth looks like.
We can act, but we don't have time to wait.
ON RADIO: From the United Nations to the US Congress,
Greta Thunberg is gaining international acclaim
for her fight to stop climate change.
Just four weeks ago,
at the start of her year out of school,
Greta was in New York addressing the United Nations.
And if you choose to fail us, I say we will never forgive you.
CHEERING AND APPLAUSE
How dare you!
Now, she and her father, Svante,
are heading far beyond the glare of the world's media
to the Canadian Rockies to see evidence of climate change.
But first, she's going north to Edmonton
to address a climate strike
in the capital of the oil-rich province of Alberta.
CROWD CHEERING
CROWD CHANT: ..get down! Keep the fossil fuels in the ground!
Get up, get down! Keep the fossil fuels in the ground!
Are you writing your speech?
No, it's already done.
I'm just reading through it
to make sure that I don't want to make any last-minute changes,
which I always do.
Maybe I should go in advance with the big bag?
We do everything together so much, but this part we don't do together.
No. I don't want him at the marches.
Father. Supportive father. That's... That's the role I play.
You know, the first time she spoke in public,
I was terrified, you know, because of her autism.
Would she run away? Would she start to cry?
Would she go silent? Would she...?
Would she do something that would hurt her?
INDISTINCT CHANTING
Will this be too warm?
Uh, no. I'd say no.
And take the stairs, cos the lift takes forever.
See you down there.
It's barely a year
since Greta first skipped school
and started a lone protest outside the Swedish parliament,
demanding action on climate change.
My name is Greta and I am 15 years old,
and I am school-striking for the climate.
We will not stop.
This is our future and this is our choice.
Since then, her act of defiance has inspired the young,
captured the attention of world leaders
and snowballed into a mass movement.
My favourite story growing up was The Emperor's New Clothes.
The Emperor is naked and everyone just pretends he isn't.
The only one who dares to question this collective lie is a child.
That story really is the story of... of ourselves,
of our society, of how the world looks now.
We climate activists are that child saying that the Emperor is naked.
Convoy with Greta is on its way.
When someone dares to say that out loud,
that changes something.
WHISTLING
Today is Friday, and as always, we are on climate strike.
CHEERING
We teenagers are not scientists, nor are we politicians,
but it seems many of us understand the science
because we have done our homework.
DRUM POUNDING, CROWD CHEERS AND CHANTS
People think that I am an angry teenager
who screams at world leaders.
That's, like, the picture people have of me.
That's not who I am.
We are doing this because our future is at stake,
and we want the people in power to unite behind the science.
CHEERING
We say, "Yeah, we're going to limit
"the global average temperature rise to 1.5."
That's what it says in the Paris Agreement.
But then we... we just continued like before,
which would be catastrophic.
That is what I'm trying to highlight.
So thank you, and continue.
Never give up.
We stand together.
DRUM POUNDING, CROWD CHEERS
In 2015, 196 states signed up to the Paris Agreement
to limit global temperature rise to well below 2 degrees Celsius
and pursue efforts to keep it to 1.5 degrees.
Greta's mission is to hold them to the agreement,
but not everyone here supports her message.
REPORTER: Here in a province that relies on resource revenue,
the sound of opposition rings loud.
HORN HONKS
We want to show Canada and Greta
that we're very environmentally friendly in Alberta
with our oil patch.
We're environmental leaders in the whole world.
Well, we're just making a little noise
to let people know that Alberta
isn't about to give up on our oil sands or oil gas sector.
We need jobs in Alberta.
Do we need Greta?
Greta, no.
The Canadian oil and gas industries employ over 170,000 people...
..and contribute over $70 billion a year to the country.
But it's also the largest contributor
to Canada's greenhouse gas emissions -
a potential trade-off between the strength of the economy
and the health of the planet.
It's a story repeated around the world.
This is what it's all about.
This is the...
..the centre, the heart of it.
The thing that drives everything, that drives the economy.
People won't see this.
They won't see how the... this oil is extracted,
how... where their petrol or where their fuel comes from.
And yet, it is destroying so many people's lives
and so much natural habitat.
Something definitely needs to change,
something drastic,
and yet, I don't know how this industry
will be able to continue if we take the action required.
But it's... It has to change. Things have to change.
ON RADIO: Average temperatures in Canada have risen
by 1.7 degrees Celsius,
twice as fast as the rest of the world.
1.7 degrees since the 1940s might not seem significant.
But to understand the impact that can have,
Greta is spending the next week
heading to three key locations in North America.
First, she's off to Jasper National Park
in Canada's Rocky Mountains.
It's home to pristine pine forests, but huge tracts are dying.
Greta's come to meet biologist Brenda Sheppard
to find out what's causing this drastic change.
What kind of different animals are there here, usually?
When I walked down here on Friday... Yeah.
..I saw a female grizzly bear with her three cubs on this trail.
Scientists have discovered that a rise in temperature
has allowed a pest to flourish and attack these trees,
leaving them defenceless.
And what is this colouring on the side?
So, this tree is all red and dead,
and it was infested by mountain pine beetle.
It eventually kills.
The females burrow in under the bark,
and then they start to eat the tissue
and build these galleries.
And inside the galleries...
It almost looks like a maze under the bark.
And she lays her eggs.
When the larvae hatch,
they feed on the tissue that the tree uses
to transport its nutrients.
Effectively, it starves.
It's rare for a tree to be able to survive
a mountain pine beetle infestation.
The needles will start to drop
and they will become kind of like skeleton trees.
The beetles have never before
caused such widespread destruction here.
Freezing winter temperatures normally kill them off.
So, approximately how cold does it need to be to...
..to kill this beetle?
We need at least several days of around minus 40,
which would be historically the norm for us.
But over the last decade,
the winters have not been cold enough any more
to kill the beetle.
The population of mountain pine beetle
has been growing and growing in the park.
About 50% of the forested area of the park has been affected.
Half of the forest.
Half the forested area, and the park is big.
Like, it's 11,000 square kilometres.
It's hard to think about. It's just...
..so big to...to understand.
Does that have any effect on any other species as well?
This tree is supporting the birds, the squirrels,
the grizzly bears, and many other species.
And the ecosystem would be changed drastically
if that species were no longer there.
You might not think that these small,
small, insignificant changes in measured temperatures
will lead to anything,
but we have to understand that ecological systems
are very complex.
If you change one tiny thing very, very slightly,
that could have devastating consequences.
What we now know is nature is all completely interconnected,
and so therefore,
when climate change affects one aspect,
it has repercussions on all other aspects.
We're living through a biodiversity crisis.
One study showed that for the best studied species,
land mammals, birds, reptiles and amphibians,
some 20% to 30% of those species
would be committed to extinction by 2050 on current trends.
It's a really shocking, worrying statistic.
There are so many species that are already endangered,
they're already at the brink.
What climate change is doing to biodiversity
is putting so much of what's left at risk.
If you look over the last ten years at drought events,
these are killing off these beautiful trees,
these absolute giants of the rainforest.
And with those trees,
you're not only losing the biodiversity
associated with the trees.
You're also losing the ability of that tree
to take up atmospheric carbon dioxide.
These trees, they're often described as the lungs of the Earth.
Take those trees away,
you lose the ability of nature to really balance our atmosphere.
Greta's commitment to activism
has seen her spend much of the last year on the road.
I want to be just a normal teenager,
but this is not a normal situation,
and I think we must step out of our comfort zones.
As a parent, I support her in what she does.
If she would have been a football player
or ballet dancing or piano playing or whatever,
I would have supported her.
So, that's what she wants to do, then so be it.
Yeah. I'll do that.
You probably wish I had picked up ballet dancing, or something.
THEY CHUCKLE I do. I do. I do.
Yeah, I do.
You know, she's so driven,
and she found a purpose and a meaning
and a joy in doing all this.
And it was just like she... she fell into place.
Svante is now driving Greta further into the Canadian Rockies.
Here, glaciers cover hundreds of square miles
and provide fresh water for millions of people in North America.
We've got a long walk to get to the ice now.
Yeah.
She's here to find out how climate change
is affecting this landscape.
Greta has joined Professor John Pomeroy
and his team of hydrologists,
who've been studying the Athabasca Glacier.
So, it was about 400 years for a snowflake to turn into ice
and then flow from the top of the Columbia Icefield
down to the Athabasca Glacier.
So, when we get up to the toe of the glacier,
we'll see ice that had formed in the Renaissance period.
Mm.
The Athabasca Glacier has been part of this vast ice field
for thousands of years.
But in just over a century,
it's lost more than a third of its volume.
When I first came here in 1979, the ice was right around here.
We didn't understand then that the glacial retreat here
was already accelerating because of human-caused climate change.
When did it become clear why?
It became clear later in the 1980s as the ice melt increased,
and this year we had the fastest melt rate
we've ever measured on the Athabasca -
six metres of ice down over the summer -
faster than our models were predicting.
Professor Pomeroy has discovered it's not just rising temperatures
that are pushing this and other glaciers to the brink.
How far up are we going?
We'll go up here onto the bare ice.
Well, this crunchy ice is weathering crust.
Underneath it, we should have the real glacier ice.
Here, take a...take a shot.
Ah. Look at that.
It's dust and soot from fires under this
because of climate change,
or more forest fires that put ash and soot onto the glacier,
and they darken it.
Dark colours absorb more sunlight and heat up faster,
so the more soot and dust from increasingly common forest fires,
the less sunlight the glacier can reflect.
Its reflectance we measured this summer was only 18%.
Normally for clean glacier ice,
we'd expect around 30%.
And that makes the glacier melt faster.
It does. It makes it melt much faster.
And it's not just here.
It's Greenland, it's the Andes, it's the Himalayas.
It's all over with the soot and the dust darkening them.
So, it's something that we didn't expect,
and it's pushing these glaciers past their tipping point.
As global temperatures rise,
the Athabasca Glacier will pass its tipping point,
and like many others around the world,
will eventually disappear.
You think of glaciers as great and powerful things,
but in fact, they're very fragile,
and we know we're not bringing this glacier back.
I knew things...things were bad,
and I have read about these kinds of things a lot,
but to really be here and to stand on the glacier,
and to...and to hear from you, who has so much experience in this,
it's just...
..it makes you realise it's... it's for real.
The glaciers of the world
are one of the canaries in the coal mine, if you like.
Even if we pause climate change now,
it's predicted that 30% to 40% of the volume of total glaciers
would be lost.
People depend heavily upon the source of fresh water
that's stored in glaciers for irrigation and for drinking.
It's been estimated that climate changes that affect glaciers
could affect nearly two billion people.
Since the early 1990s,
Earth has lost 28 trillion tonnes of ice,
and that's a huge number.
So, that's arising from melting mountain glaciers,
the polar ice sheets,
and sea ice in both polar oceans.
When the water ends up in the sea, as it ultimately will do,
that'll cause sea levels to rise.
Some climate models predict an extra metre of sea level rise
by the end of this century.
This is a real consequence
for large numbers of people around the planet.
Sea level rise has had a significant impact on the life
within the Caribbean region.
There's always a place
where somebody can point to a location in the sea and say,
"I can remember when that location
"used to be on the land."
Almost every coastline in the world
is susceptible to changing sea levels.
Everything is going to change.
The question is just,
will the changes be on our terms or on nature's terms?
We just have to choose.
But the more time goes by, the more that opportunity decreases.
In six weeks' time,
Greta is due to address a UN climate conference
in South America...
..so she and Svante are heading south through California...
..in a country where climate change is a very divisive issue.
TV HOST: Greta, listen very closely.
Climate change is not going to kill you.
The world is not going to end in 12 years.
You can have babies and you will have a future.
People don't want to talk about the climate,
so they make it about...about me.
Greta... You know Greta?
CROWD JEERS AND BOOS
I'm such a public figure
and everything I do gets completely twisted.
Today, I am proud to introduce to you Greta Thunberg.
CHEERING
People spend all their time online spreading conspiracy theories
and send death threats to me and my family.
There's been some, you know, dark moments.
In those moments, I've told her, you know, "Either you...
"You know, you want to do this, then you do it.
"If you don't want to do it, we go home now."
We are living in the beginning
of a climate and ecological breakdown,
and we cannot continue to look away from this crisis any more.
CHEERING
I don't mind the hate.
I don't care what people say about me,
but it's just when it becomes, like, physical
and when it affects your family,
that's a whole other different story.
Thank you.
CHEERING AND APPLAUSE
Not many have experienced something like this at such a young age.
So, yeah.
For the last few years,
California has been ravaged by wildfires.
NEWS PRESENTER: There are over 8,000 firefighters
currently fighting fires throughout the state.
To date, over 209,000 acres have burned.
Close to a quarter of a million Californians have been evacuated.
In 2018, the town of Paradise was almost completely destroyed.
This looks kind of bad.
These were all houses.
God, these dead trees.
All the root system.
Hi. Good to meet you. You too.
Greta is meeting local resident Julian Martinez,
who only just escaped the wildfire with his life.
This tree stump right here used to be maybe a 120-foot-tall pine tree,
and that was my front porch.
When did the fire occur?
November 8th, 2018.
That morning, I woke up at seven o'clock,
and I could hear the wind outside, which was really strong.
And over in about that direction right there,
you could see a plume of smoke.
And so at about eight o'clock we said,
"OK, we've got to start packing up to get out of here."
Right when we were about to pull out,
the sky just blacked out
and it looked like night-time all of a sudden.
And we were able to get out before the town gridlocked.
HEAVY BREATHING
ON RADIO: ..ordering an evacuation order now due to the fire...
As the wildfire engulfed Paradise, its 27,000 residents tried to flee,
many recording their escape.
There's nowhere to go.
Oh, my God. Oh, my God. Oh, my God. I don't want to get caught there.
It's starting to burn all around me.
Oh, my God. Oh, my God!
Burning right here!
Come on, people! Go!
The flames moved so intensely, you know,
it went from a minor thing to the whole town was gone
within a couple of hours.
And the roads kind of acted like a funnel through the flames.
There's stuff really burning on all sides.
Heavenly Father, please help us.
We're never getting out of here.
HORN HONKS Come on!
Are they finished? Come on!
Let's go! Let's go! INDISTINCT SHOUTING
TEARFULLY: Dear God, help me to get out of this!
Please! Please!
I think 86 people died in the fire.
There's a sense of guilt that I have for leaving town so quickly.
TEARFULLY: You know, knowing that there were...
HE EXHALES SHARPLY
Sorry. I completely understand. It must be very hard.
There were a lot of people that needed help.
So, you know, knowing that those other people were left behind
is something that has stuck with me.
I feel it's just so incredibly sad, I can't...
..I can't imagine what you have been going through.
The wildfire that engulfed Paradise
was the deadliest California has ever seen.
NEWS PRESENTER: Many of the dead were found in burned-out cars
and destroyed buildings.
The town is still recovering.
There's been people who have committed suicide after the fire
just because they've had their lives taken away from them.
I mean, even right now, as we're speaking,
there's fires that are popping up all over California.
When you hear about these stories,
and especially when you meet these people,
you try to imagine yourself in that situation.
How difficult it must have been to lose everything
and just leave everything behind.
We see all of these things repeating themselves over and over again.
People die and people suffer from it,
but we completely fail to connect the dots.
NEWS PRESENTER: Wildfires are continuing to engulf
large parts of the West Coast of the United States.
At least 35 people have died.
Thousands of homes have been burnt.
The blazes have destroyed nearly five million acres
across three states,
fuelling accusations that President Trump is in denial
about climate change.
He blames the fires on poor forestry management.
To discover the role played by climate change,
Greta is meeting Professor LeRoy Westerling.
He's researching the connection between climate,
ecosystems and wildfires.
This is an area where fires are a natural part of the ecosystems,
but what has changed?
Increased temperatures means more evaporation,
and it's drawing that moisture from the live or dead fuels.
Climate change is also altering the pattern of the air currents
that drive global weather.
In California,
the autumn rains are now arriving later.
We see a greater chance of storms in the fall getting missed,
and if we lose our fall storms,
then our dry summer season extends that much later,
so the fuels continue to dry out even more.
What was making the wildfires more...more intense?
We get these winds in the fall.
And these high-wind events,
combined with these extremely dry fuels,
gives sort of perfect conditions for a really big fire
that spreads very quickly and is hard to get under control.
Even if we succeed
in keeping the global temperature rise to below 1.5 degrees,
what would the future look like?
At elevations like this, we're going to see even more fire.
Five of the ten worst wildfires on record in California
burned during summer 2020.
Thousands of buildings and structures destroyed,
dozens of lives lost.
A tragedy by any measure.
Climate change is increasing forest fires
in many parts of the world.
In Siberia, in Russia, in Alaska.
And then you also have seen that in Australia with the bushfires.
So, these wildfires, then,
are part of a larger climate feedback loop.
You warm up the higher latitudes,
the pine bark beetle moves into those forests,
weakens those forests,
so there's more dry and dead wood
to come together with that drought and heat
to give us those massive wildfires,
and they put more carbon pollution into the atmosphere,
causing more warming.
Greta and Svante have just over a month
to reach the UN climate change conference in Chile.
But anti-government riots
have broken out in the capital, Santiago.
REPORTER: The authorities have used water cannon
to disperse the crowds without success.
The United Nations has decided
to relocate the climate conference to Spain
on the other side of the Atlantic.
SIREN WAILS
I've been going pretty much
the whole way around the world the wrong way,
so now we are headed east,
and hopefully I will find transport that can take me
to the other side of the Atlantic Ocean.
For almost anyone else,
this journey of over 3,500 miles
would mean hopping on a plane for 7.5 hours.
But not for Greta.
Flying or getting on a plane, she would just refuse.
She wouldn't... She wouldn't do it.
Greta Thunberg has asked her followers
on social media for help getting back to Europe
in an environmentally friendly way.
I don't want to be the person who says,
"Yes, climate change is very important,"
and then the next second steps onto a plane.
Aviation burns through a lot of fossil fuel.
If a Boeing 747
flies from London to Hong Kong,
it burns through something like 100 tonnes of fossil fuel.
When you burn the fossil fuels,
you get a lot of other pollutants that come out
the back of the exhaust of the plane.
Because the chemicals are emitted at altitude,
it has an impact chemically in the atmosphere,
approximately something like doubling the amount of warming
that you would otherwise get.
In lots of countries,
only a very small proportion of the population ever flies,
but of course, some people fly a lot.
Globally, it's only 1% of the population
that account for about half of all aviation-related emissions.
Of course, the coronavirus pandemic's had a huge impact
on the aviation industry,
and the key question is whether people just go back to flying
to the extent that they were before, or whether they seek alternatives.
We don't have to have a no-flying world,
but there's no escaping the need to reduce the amount
of flying that goes on.
Greta and Svante have been offered a lift back to Europe
on a 48-foot catamaran called La Vagabonde.
Greta has already sailed across the Atlantic once this year
to get to the USA,
but that was in August, when the weather tends to be calmer.
It's not the perfect time to be leaving.
We've got the Gulf Stream to cross, and there's just consistent lows.
One low after another after another.
There's no denying that it's going to be a tough trip.
We're ready. As ready as we can be!
Today is probably the most stressful day of my life.
It's November and it's the Atlantic Ocean.
It's going to be pretty rough, I think.
Just silently panicking inside.
The joys of parenting. HE LAUGHS
The voyage probably will take two to three weeks,
all being well.
But we are at the mercy of Mother Nature,
so whatever she decides to throw at us,
we will have to manage.
The weather systems are very bad, and this time of year,
you don't sail across the North Atlantic
in November or December.
It is very symbolic that I sail, because it sends a strong message.
CAMERA SHUTTERS CLICKING
All right, ready when you are.
REPORTER: Greta Thunberg is back on the open seas.
The 16-year-old climate activist set sail from Virginia
for a transatlantic journey to Madrid.
Yay! We're finally on our way.
WEATHER HOST: You have tropical depression in the central Atlantic.
Could become a tropical storm sometime today or tomorrow,
curving out to sea, staying away from the US.
It is day one.
I'm... I have not been feeling very well today.
It's... It's cold, and I'm a bit seasick.
So, yeah, hopefully things will get better.
WEATHER HOST: Yes, it is expected to become a tropical storm.
It's in the central Atlantic now.
THUNDER CRASHES
We are in just the biggest electrical storm,
blowing 40 knots, and Nikki's at the helm.
WAVES CRASH VIOLENTLY
It is day six.
It's the middle of the night and the lightning was unbelievable.
I've never seen...
..such lightning.
It struck, like, every two seconds, and the whole sky just lit up.
We had lightning striking the water everywhere.
HE IMITATES HISS OF ELECTRICITY
You could hear the water going, "Fsss!"
And it just went on. It never stopped.
The storms are so enormous.
It was just a constant game of avoiding the next big storm.
THUNDER CRASHES
In the Atlantic, we just saw the busiest season for storms,
and it coincided with the year
that had very warm ocean temperatures
in the tropical Atlantic.
The global ocean's surface
warmed up close to about a degree Celsius,
so when you provide more warmth, those winds can get stronger,
they become more intense, they do more damage.
Some argue we need to invent a category six
to describe these 200mph monster storms
that we're now seeing.
There is another impact.
The oceans absorb a lot of the carbon dioxide
that we put into the atmosphere.
When CO2 dissolves into the water,
it forms a weak acid,
and that affects the chemistry of the ocean
in a way that can be bad for some ecosystems.
One of the types of marine life that is most dramatically impacted
by ocean acidification is coral reefs.
Coral reefs are the home to a large portion
of the world's biodiversity,
but scientists are predicting that with 1.5 degrees Celsius
of global temperature increase,
we'll lose around 90% of our tropical coral reefs.
And with 2 degrees Celsius of warming,
we'll lose 99% of coral reefs.
There are some things we can do to reduce CO2 emissions.
Shipping is really interesting.
So, if you halve the speed with which ships go,
you more than halve the CO2 emissions that come from them.
And we saw this during the global financial crisis,
where we saw a big drop in CO2 emissions.
So, thinking hard about how we move freight and people around the world
is really important.
We are approximately halfway.
The weather forecast looks good.
It's just an amazing experience to be able to...
..to just be out here in this wilderness
and to look at the ocean.
And time sort of doesn't exist out here.
You just...
..live in the moment.
You feel calm.
I think that was something I needed, because it can get very overwhelming
constantly being in the centre of attention.
That was very enjoyable to just be invisible,
to just become myself.
The ocean was a very pleasant place to be.
You're completely shut off from the world.
It changes you, in a way.
You just sit there for hours and hours...
..completely surrounded by this wilderness.
You see how big the world actually is, and these...
..vast oceans that cover most of the globe,
and how important they are to all of us.
20 days after leaving the USA,
Greta and La Vagabonde
are approaching the Portuguese capital, Lisbon.
You come from nothing, and just you and the ocean,
and then suddenly, land.
CHANTING AND DRUMMING
REPORTER: The teenage activist Greta Thunberg
has re-crossed the Atlantic
on her way to a conference where governments are debating
what to do to stop the planet overheating.
And all that comes with that pollution,
all the noises.
CHANTING AND DRUMMING
And then you have all these cameras in your face.
Sometimes it gets too overwhelming,
and also, if you're autistic, it's...
..it becomes even more.
From Lisbon, Greta is taking the train
to the UN Climate Change Conference in Madrid.
CAMERA SHUTTERS CLICKING
It's a chance to prepare the speech she's been asked to give.
She's very, very driven,
and she doesn't want to waste any time.
She reads a lot of books, a lot of articles about science.
I know there have been many new reports coming out,
and many new figures to look at.
This morning, I saw that the global emissions
of greenhouse gases for 2019 will increase,
and also, 2010 to 2019 will most likely be
the hottest decade ever recorded.
When I was younger,
I pictured my future being some kind of scientist
working in the lab,
never seeing the daylight. SHE CHUCKLES
That's what I thought I was going to be like
when I grew up.
But it didn't really turn out like that.
CAMERA SHUTTERS CLICKING
SHE SPEAKS IN SPANISH
REPORTER: It is incredible
to witness the phenomenon of Greta Thunberg,
who in the space of a year,
has gone from solo protest outside the Swedish parliament
to galvanising millions of people in the fight against climate change.
CLAMOURING
If I'm going to reach out to this many people
and bring attention to the climate crisis,
then this is something that I have to accept,
because with that big of a platform
comes much attention and responsibility.
The United Nations' annual climate conference, known as COP,
gives the world's governments an opportunity to meet
and negotiate a way to keep to an agreed level
of global average temperature rise.
REPORTER: COP25, just the latest instalment
in a quarter-century of diplomacy
that's so far failed to curb climate change.
In terms of the time scale at which we need to stop emitting
carbon dioxide into the atmosphere,
we have this concept called the carbon budget.
The carbon budget, simply put, is how much carbon we can burn
and keep global temperatures below some level.
And we know, for example,
that we can still keep them below 1.5 degrees Celsius.
So, that budget is somewhere
between about 200 to 300 billion tonnes
of carbon dioxide.
That may sound like a lot,
but we're emitting about 40 billion tonnes of carbon dioxide per year.
If you do the math,
what that means is that if we continue to emit carbon
at our current pace, we're going to run through
and deplete that budget by 2030.
And if we had acted 20 or 30 years ago,
we could bring our carbon emissions down gently
over several decades.
It would've been much easier.
So instead of a gradual drawdown of emissions,
we're going to have to jump off of a steep cliff
in order to get those reductions.
If you think about 2020 and the lockdown, in the end,
that only bought us about 7% reduction in carbon emissions.
So, we've got to do much more than that
if we are to avert dangerous planetary warming.
With almost all the world's nations
set to overshoot their carbon budgets,
Greta is planning to use her speech
to demand that governments honour the promises they've made
on climate change.
But maybe it's... Yeah. Yeah, there he was.
No, but it wasn't the document.
More...
Even at 1 degree, people are dying from...
People are only listening to the...the emotional bits,
like, "How dare you!"
and, "I want you to panic," and so on.
I say these things because they get people's attention,
and now I have people's attention,
I don't need to make a speech like that.
I want them to listen to the actual content and the science.
Could I take a picture?
Yeah, could you do it quick? Because I'm late.
I don't know if this will... will shift the focus.
It probably won't.
The headline will be,
"Greta Thunberg makes emotional speech."
I know that that's going to be the reaction,
but I'm doing everything I can at least
to make sure that that's not the case.
REPORTER: There are 29,000 delegates at this climate summit,
but only one receiving this much attention.
Now I would like to invite to the stage to take the lecture,
Miss Greta Thunberg.
CHEERING AND APPLAUSE
Hi.
I've given many speeches
and learned that when you talk in public,
you should start with something personal or emotional
to get everyone's attention.
But today, I will not do that,
because then those phrases are all that people focus on.
They don't remember the facts,
the very reason why I say those things in the first place.
We no longer have time to leave out the science.
If we are to have a 67% chance
of limiting the global temperature rise
to below 1.5 degrees Celsius,
we had on January 1st, 2018,
420 gigatonnes of CO2 left to emit.
With today's emissions levels,
that remaining budget will be gone within about eight years.
These numbers aren't anyone's opinions
or political views.
This is the current best available science.
APPLAUSE
These numbers don't include non-linear tipping points
such as melting glaciers.
We know we're not bringing this glacier back,
but it's all being driven by climate change
that's caused by greenhouse gases.
To stay below 1.5 degrees,
we need to keep the carbon in the ground,
because even at 1 degree,
people are dying from the climate crisis.
It's starting to burn all around me!
I have been fortunate enough to travel around the world,
and I still believe politicians and CEOs
are making it look like real action is happening,
when in fact, almost nothing is being done
apart from clever accounting and creative PR.
CHEERING AND APPLAUSE
This is my message.
This is what I want you to focus on.
Right now, we are desperate for any sign of hope.
People are ready for change.
Thank you.
CHEERING AND APPLAUSE
NEWS PRESENTER: The 16-year-old climate activist Greta Thunberg
accused richer countries of being more interested
in finding loopholes in environmental laws
than tackling...
NEWS PRESENTER: Environmental campaigner Greta Thunberg
has accused governments and corporations
of failing to tackle climate change.
The people who hosted the event were very happy afterwards
because I wasn't angry.
Because I think everyone expected me to go up and shout.
I at least tried to get the information out there
and make sure that the gap between what politicians are doing
and what the science says
is so clear that no-one can avoid seeing it.
2019 is coming to a close, but next year,
Greta has an even busier global journey planned.
First, after 134 days on the road, she's taking a Christmas break.
We're in Copenhagen right now,
and we are going to the central station,
where we will take a train, a direct train,
from Copenhagen to Stockholm.
So, right now we're going home.
Thank you so much. Thank you. Thank you so much.
It was nice meeting you. Thank you. You too. You're really cool. Bye.
On the peninsula, on that side, they do.
There's Sweden. We can see it now.
SHE SPEAKS IN SWEDISH
MUSIC: Stilla Natt by Malena Ernman
Many people often ask me whether I'm an optimist
or...or a pessimist.
I don't think that we need to feel hopeful in order to act.
The only thing that creates hope is action,
and if there is no action, there is no hope.
DOGS PANT
THEY SPEAK IN SWEDISH
Next time...
..Greta investigates our reliance on fossil fuels...
..discovers how climate change is reshaping our landscape...
As soon as the ice in the rock starts to get warmer,
that stabilising influence disappears.
..and seeks advice from a veteran campaigner.
People are listening.
And there just could be a change in moral attitude
from people worldwide.
To find out more about climate change and explore
what actions you can take to reduce your environmental impact,
go to bbc.co.uk/ayeartochangetheworld
and follow the links to the Open University.