So I'm going to talk to you
about carbon removals,
and I’m going to start with this.
This is a woolly pig.
(Laughter)
She's gorgeous, obviously,
and she’s also one part
in a whole new set of approaches
for dealing with climate change.
They are all called carbon removals,
and they all involve
taking CO2 out of the sky
and storing it somewhere safe.
I’ll come back to the woolly pig later,
but first, why do we need carbon removals?
Because I know what you’re thinking:
isn’t it easier to stop
putting the carbon in the atmosphere
in the first place?
And the answer is yes, of course it is.
We have to do everything we can
as fast as we can
to stop carbon getting into the sky
and stop climate change getting worse.
That should not be a controversial
point of view at this meeting.
But the problem is ...
we’ve left it too late.
We can't now do it fast enough.
I've been working on climate change
for more than 20 years,
and I’ve talked about it
in boardrooms and classrooms
and everywhere in between,
and I was shocked when I found this out,
but the science is utterly ...
utterly clear.
If we’re going to have a fighting chance
of staying below 1.5 degrees,
that “safe limit,”
we have to have carbon removals,
and it looks like
we’re going to need a lot.
Scenarios from the Energy
Transitions Commission,
from the International Energy Agency,
from the Intergovernmental Panel
on Climate Change,
have all shown that we’re going to need
billions of tonnes of carbon removals
between now and 2050
to give us a chance
of staying below 1.5 degrees.
We’re going to need
both reductions and removals.
But there's another more heartening reason
why we need carbon removals.
They also give us a chance --
our only chance --
not just to stop the problem
getting worse,
but to make it better.
Because even 1.5 degrees
isn't actually safe.
We’re not there yet, and we’re already
experiencing the fires and the floods
and the droughts and the storms.
With carbon removals,
we can take our historical emissions
out of the atmosphere.
We can clean up the mess we’ve made,
and we can give our world
a chance to heal.
So what do the removals look like?
I’ve been talking to a lot of people
about carbon removals,
from business executives
to climate activists,
and they tend to go one of two ways.
They either think of trees
or they think of big, futuristic machines.
Nature versus tech;
green versus chrome.
But the more I’ve dug
into carbon removals,
the more I’ve realized this is not
the right way to think about them.
Because the world
is full of ways to store carbon.
You can store it in trees,
you can store it in soils,
you can store it in the ocean,
you can store it in buildings,
you can store it in rocks,
you can store it deep underground.
And every one of those approaches requires
some combination of natural resources
and human ingenuity
and technology.
We’re going to need
both nature and technology.
I'll show you what I mean.
So we start on the natural
end of the spectrum with trees.
Now, I still find it astonishing
that every single tree and plant on Earth
has made its entire body
directly from carbon in the air.
They’re incredible
carbon capture machines,
and we’re going to need
a lot more of them.
But we also have to do it right,
because if you put trees
in the wrong place ...
they burn.
We have to put trees in places
where they foster biodiversity,
where they don’t compete
with food for land
and where science and technology
tell us they are likely to survive
even in the face of climate change.
Now, if you don’t want
that CO2 from the burning trees
to get into the sky,
you can actually burn the wood
deliberately in a power station,
capture the CO2
and bury it in a process known as BECCS,
which also gives you energy as a sideline.
But if you want to keep
the carbon locked up in the wood,
there are technological ways
to do that as well,
like this one.
Look at this.
A whole new movement
to use wood as a building material
in modern, high-rise buildings.
That’s a good idea
for at least three reasons.
First of all, it keeps
the carbon locked up in the wood.
Secondly, it displaces
high-emitting materials like concrete.
And thirdly, the buildings are gorgeous.
Now you can also use technology
to help carbon stay locked up in soil.
Storing carbon in soil
sounds like a good idea,
and it is a good idea.
The question is how long
does the carbon stay there?
Because if you change your agricultural
practices for one year, two years,
that’s fine.
But if you ever go back to the old ways,
the carbon goes back up into the sky.
That’s why this stuff can help.
It’s called biochar,
and you make it by taking wood
and burning it in the absence of oxygen
until you get this.
It locks the carbon up in the wood,
and now it can’t burn away.
Now, it turns out that biochar
is very good for soils.
In fact, Indigenous people in the Amazon
have been using it for generations
to improve the quality of their soil.
We can do that on a much bigger scale,
improve the soil
and lock up carbon.
That’s nature
and technology
and Indigenous wisdom,
all in one sweet package.
Now you can use technology as well ...
to speed up natural processes.
So this is basalt.
It’s a volcanic rock.
You can find it more or less
everywhere on Earth,
and it naturally takes up CO2
in a process called chemical weathering.
Unfortunately, it takes
thousands of years to do it.
But you can speed up the process
if you grind up the rock
and spread it on fields,
and then you can speed it up
to just a couple of years.
And like biochar, it’s good for the soil.
You get minerals in the soil
where you need them.
And when it washes off into the sea,
it can also help with another
big bugbear of climate change:
ocean acidification.
And if we did this on two-thirds
of the world’s croplands,
we could potentially take
up to four billion tonnes of carbon
from the atmosphere every year,
which is a very big chunk of what we need.
Now, these approaches so far,
like planting trees,
take a lot of land
to be able to get them to scale.
But there is one approach
where you can actually do it
in a very small amount of land,
but still get to scale.
It’s called direct air capture,
and it basically involves
massive electric fans blowing a lot of air
over a carbon capture device.
Now, OK, this does look
like a big, futuristic machine.
I admit that.
But it’s still marrying technology
with a natural process --
geology --
because when you’ve captured the CO2,
you bury it deep underground.
This is an artist’s impression
of a plant that’s being designed
by Carbon Engineering in Texas.
And its aim is that it will take up
one million tonnes of CO2
from the atmosphere every year.
And I love this bit --
where does it go?
They put it deep underground
in the same geological formations
that the Texas oil
was originally squeezed out of.
I love the poetry of this.
It’s like reversing the valve
and putting the CO2
back where it came from.
And recent studies have shown
that if you do that,
98 percent of it will still
be there in 10,000 years.
When you put it down,
it stays down.
This is still a little bit futuristic.
It’s still in the planning
and design stages,
but this carbon capture plant
started operating this year.
A smaller scale,
but it’s already doing it.
This is Climeworks and Carbfix in Iceland.
They're using geothermal heat to power it,
and they’re putting the CO2
into the Icelandic basaltic rock.
So one issue, though,
with direct air capture,
is it takes a lot of energy
to power those fans.
And that energy obviously has to be green.
It has to be clean;
you can’t use fossil fuels for it.
But it also makes it much more expensive
than other techniques.
And it takes energy to cook wood
and to grind rock,
and so all of those approaches
I’m talking about
are currently much more expensive
than planting trees.
But we can do something about that.
We can invest in it now,
do the research and development
and get them down the cost curve
to make them affordable.
It worked for solar power;
it worked for wind;
it can work for carbon removals, too.
Remember, we have to get
to very big scale:
billions of tonnes
of carbon removals by 2050.
But we can all help by reducing
our emissions as much as possible
and figuring out how to remove the rest.
I’m not talking conventional offsets.
You know, I put a tonne of CO2 in the air,
and I pay you not to put
your tonne in the air,
but my tonne’s still there.
No, what I mean is I put
a tonne of CO2 in the air,
I pay someone to take a tonne
out of the air, now or in the near future,
and we can get to zero and beyond.
What goes up must now come down.
And if we all do that,
if we all make that commitment,
then the people trying to make
removals happen will have the finance
and the courage
and the confidence to be able
to get to the scale that we need.
I don’t know which of all
of these approaches,
in the end,
are going to be the ones
that we’ll have to use
to get us to the scale we need.
But I do know that we’re going to need
a whole spread of them,
with nature and technology
working hand in hand
to take CO2 out of the sky
and keep it out.
Which brings me neatly back ...
to the woolly pigs.
(Laughter)
Now, these woolly pigs live
on an estate on the Isle of Mull,
which is owned by Jim Mann’s
Future Forest Company.
And I know they don’t look very dangerous,
but they are actually
the closest you can get
to a native Scottish wild boar
without having to have
a dangerous animals license.
And they do what the Scottish
wild boars used to do.
They rootle up the undergrowth
left over from selective grazing.
They let the seed bank
come to the surface
so that native trees can start to grow
and start to take up CO2 from the sky.
They're also planting trees
in this lovely place.
Native broadleaf like oak
and this beech tree,
and it’s plenty wet enough
on the Isle of Mull
that they’re not likely to burn.
So that’s so far, so natural
But they also have machines.
This one is getting ready to cook wood
for biochar to go on the soils,
and they’ve also got a quarry with basalt.
They’re quarrying basalt rock.
They’ve got machines to grind up the rock,
and they’ve got machines
to spread it on the fields.
That's three carbon removals approaches
in one beautiful place.
Now, it’s just one estate,
but all of these approaches
and more are hugely scalable.
The world is full of places
where you can plant trees
and put carbon in soil
and grind up rock and spread it
and capture CO2 from the air
and find places to store it underground.
All of those things.
And there’s hundreds --
thousands of people working right now
to get those carbon removals approaches
out of the textbook
and into practice,
and to help us --
God help us --
reverse the damage we have done
and start the process of climate healing.
And when I sat on that hillside,
and I saw the pigs rootling
and the trees growing
and the machines
getting ready to cook and grind,
I loved it ...
because I experienced an emotion
that those of us who work
on climate change
very rarely experience.
I felt hope.
Thank you.
(Applause and cheers)