Translator: Olivier PAPIN Reviewer: Hélène Vernet
Let me talk to you about a place well known to you.
You likely go there often or perhaps even live there.
Nevertheless, it’s a place not very easy to live in.
This place ...
is the city.
Why is it so hard, nowadays, to live in the city?
Why do we have to be tough when we live in the city?
Cities emit greenhouse gases.
There are atmospheric pollution,
light pollution,
and noise pollution.
So it’s not easy to live in cities.
This photo that I took last year in China
shows how difficult it can be to live in a city.
You might be thinking,
"What a shame the picture wasn't taken on a nice day!"
In fact, that day was a nice day.
On that day, the weather was nice in Wuhan,
a small town of 10 million people that nobody's ever heard of.
This area has only 30 million inhabitants, so no wonder you don't know it.
In fact, on that day, the sun was there,
like some kind of halo gently passing through the sky.
And why couldn’t we see it?
Because the concentration of pollutants had reached a very high level.
As for us, we have an alert threshold at 70 micrograms per cubic meter.
70 micrograms per cubic meter
is the amount of poison
above which we consider that we need to be careful.
On that day, it was somewhere around 250, 300.
My personal record in China: 450.
On that day, we bought masks though.
The record in China is sometimes over 1,000, sometimes 1,200.
To give you an idea, there was a day when the air was so polluted
that when a building caught fire, which happened to be empty,
actually nobody noticed it
because we couldn’t distinguish between the smoke from the fire
and pollution.
Obviously, we haven't reached that point.
But at the same time, with this week’s news,
I could have taken a similar photo in Paris, Lyon or Bordeaux
featuring a nice cloud of pollution.
Tomorrow’s territories, if they are to be resilient,
need to be imagined, planned and designed
so that they can offer resistance, resilience,
particularly to the current climate change.
Indeed, town planners, architects,
local authorities with whom we work,
we’re all trying to think about what solutions to offer.
First, we're looking at what is already being done.
There are solutions that are a bit crazy.
There’s a Chinese artist called Wang Renzheng,
who walked around with his vacuum cleaner.
He vacuumed ... the air.
Then, he created bricks from what he collected in the air.
There’s another artist who made diamonds from it.
Well, that’s not enough.
There’s a Dutch designer who thought,
"Let's filter the air by installing big pumps that filter the atmosphere
and take out all these particles so that we could depollute the city."
The University of Calgary came up with traps for greenhouse gases
to stop those emissions from the city.
They trap them before they are released.
The city of Beijing,
which last year experienced 175 days of high pollution,
came up with huge fans
that could blow the pollution away and remove it from the city.
As for us, in France, we thought,
"These solutions are interesting, but the problem is they consume energy,
and they will end up being part of the problem they’re trying to solve."
Naturally, we have to think about
how to reduce those emissions and pollutants,
but tools exist.
So, we looked for a tool that would be of our times,
low-tech -
since the impact of electronic appliances is high -
and that would consume little or no energy.
Therefore, we looked for a tool that uses solar energy
and ... a little water,
and it should be a disconnected tool.
Smartphones, firmware updates, all these are too complicated -
a disconnected tool.
Then we thought, "We're in 2016, so this tool must also be gluten-free!"
This tool, I didn’t bring it with me,
but I suggest that we see it at work.
Here it is.
Is it the car that will become electric?
Is it the smart-grid hidden in the streets that no one will notice?
No. As you've already understood, this tool has always been here.
In fact, we’d forgotten it is here.
The tool I’m talking about is, of course, that tree.
Because today, that tree,
cities, architects, urban planners, engineers, see it as something ornamental.
I don’t know if you’ve ever seen the design for a neighborhood;
trees are green circles that are placed here and there on Autocad.
These green circles are placed, sparsely, everywhere.
Today, we need to go beyond the ornamental function of this tree.
Meaning, this tree,
although we don’t realize it, is doing us a lot of favors.
Later, as you will leave and before reaching home,
you'll see that tree and ask yourself:
"What functions does it perform?"
And that’s what we call: "ecosystem services,"
services provided by Nature.
So that tree has many advantages.
It stores carbon.
It depollutes the atmosphere.
It helps fight against what we call "urban heat islands,"
the fact that it’s very hot in cities.
Did you know that a tree equals five air-conditioners?
This tree has even other virtues which we don’t think of.
If you ever get sick,
there’s a study that shows that if your window opens onto a tree,
you have a greater chance to recover.
Finally, a study by researchers from Illinois shows
that when we plant trees in a city, it even reduces crime.
So, this truly goes far beyond what we know.
When we mention this in the projects on which we work,
cities often say, 'Yes, but it costs money.
You have to plant them and look after them.
Our economic environment is tough, so what to do?"
Here’s the answer.
When I invest one dollar in a tree, it returns 5.60 dollars.
That’s not coming from me but from the city of New York.
So imagine: if even the Americans are telling us trees are profitable,
that means we can really go for it!
The idea is to know
that what is invisible provides services for the city
and for the territory,
and tomorrow, we're going to make use of these tools
as tools to make our territories resilient.
So, it’s really important to change this paradigm.
So, what to do?
Indeed, we have to plant trees.
New York brought together its residents in order to plant one million trees.
It reached its goal one to two years before its initial expectation.
So you - you need to fight,
because you can’t imagine
how high the temptation is in town planning projects
to get rid of trees.
Engineers think, "Cutting down a tree, placing another one; it's all the same."
I’m an engineer.
In reality, a mature tree has taken time to fully develop
and to acquire its functions.
So, replacing a tree by another tree doesn’t work.
In the future, we will plan territories.
We’ll go as far as choosing the tree species
depending on the services we want to provide.
We’ll choose a species that will decontaminate near a road.
We’ll choose a species that will stock carbon truly well.
This won’t stop us from considering how we can reduce our emissions,
but in any case,
it's a way to restore Nature to its rightful place in the city.
For you, it's not easy to chose which kind of tree to use,
but nobody goes wrong by planting a tree.
"Antoine, he is stressed.
Can you imagine, I just saw Antoine,
he’s really stressed, he’s not well, he’s been really stressed all week.
- Really, what happened? - He screwed up a project, he screwed up!
- Really, what did he do? - He planted a tree!"
We can’t go wrong.
Because a tree,
when it has reached the very end of its life,
even then when we no longer need it,
it is still very useful to us.
We can use it for fire-wood, wood for construction.
We can profit from the whole tree.
Therefore, we can think about the use of a tree during its whole life cycle.
We need to go and look for places to plant trees -
parks, gardens, streets - and think thoroughly about that.
There’s an experiment in North America
which is really interesting and which has a funny name.
It is called "Sneckdown."
It’s true that for us with climate change, snow is not always easy to find.
What is involved in Sneckdown?
It’s simply that when it snows over there, you can see where cars drive.
Which place of the street is strictly needed for them to pass through?
All places that are full of snow,
after all, are places that can be taken back.
Therefore, in those places that we can take back,
we plant trees, build bike lanes, place street furniture,
offer terraces to restaurants.
In fact, we take back urban space and make it serve our territory.
Now, I’m going to ask you to imagine
that we’re back at the start of the 2000s.
High-speed internet is really starting to expand.
Wi-Fi is coming ...
Imagine that trees distribute Wi-Fi.
How many trees would be out there?
There would even be one in this room
so that you could be on your smartphones, and me too.
So many trees would be planted
that we certainly could save the climate, biodiversity and cities,
and all that would be amazing.
Unfortunately trees don’t distribute Wi-Fi,
they only produce the oxygen that we need to live.
Thank you.
(Applause)