So in my city of Athens, Greece,
like in many cities around the world,
a lot of people thought that climate change
is something happening far away.
Until ash started falling from the sky
and temperatures neared 45 degrees Celsius
in the summer of 2021,
and they stayed above 40 degrees for several days.
The asphalt sizzled and huge wildfires burned the forests around the city
and people died.
The last decade has been the hottest ever recorded in our history.
Paradoxically, even though we've been talking about global warming for decades,
we haven't been talking about extreme heat,
especially in urban environments.
Extreme heat is the deadliest of all extreme weather phenomena.
Very few of us know this.
We overlook extreme heat
because heat doesn't come with the drama of roofs sent flying
and streets turned into rivers.
Heat destroys quietly.
Yet there is little escape from heat.
These are temperatures our bodies are not made for and cannot adapt to.
These are temperatures our cities and our infrastructure is not made for.
The structures of our cities
and the surfaces absorb heat and store it and radiate it at night.
Cars and air conditioning add more to the urban environment.
And this is a deadly mix.
This is what we call the urban heat island.
The list of health effects from heat and from heat waves is long,
and it includes significant mental problems,
mental health problems.
It also,
heat creates fatigue and loss of sleep,
which in turn increases workplace injuries
as well as significant losses of productivity.
Heat waves also, we know,
that they increase violence in communities,
we have correlated it to increased violence in communities,
and also they lower the ability of children to learn.
And in the cities,
not everybody, of course, is affected equally.
The poor, especially the energy-poor and the housing-poor are most vulnerable
as well as people with pre-existing conditions,
people above 60 years old,
pregnant women, young children
and people that have manual labor jobs.
Also, we know that heat has been baking farmers' crops,
reducing yields,
inhibiting pollination,
and more and more farm workers are going to work before daybreak
or farming in the night, harvesting in the night.
It's just getting too darn hot.
The great infrastructures that we have built
with ingenuity and effort
during the last two centuries,
the dams, the waterways, the highways, the railways,
they have been carefully engineered for a climate that no longer exists.
What can we do?
I will talk about cities because that's my territory.
As chief health officer of Athens,
I think of all possible efforts in three general categories.
Awareness,
preparedness and redesign.
Awareness means that we recognize the threat.
It's hard sometimes to persuade people, especially in hot climates,
to take heat exposure seriously.
So this year, together with the Arsht-Rockefeller Resilience Center,
we are going to pilot, for the first time this summer,
four cities in the US and Athens,
we're going to pilot a new methodology for naming
and categorizing heat waves like we do hurricanes.
So consider this.
When there is a category 4 hurricane,
you don't expect the pizza delivery person to bring a pizza to your house,
nor do you expect, like, people to keep working in a construction site.
However, we don't have such considerations or policies
in relation to a category 4 heat wave
because there is no category 4 heat waves.
We don’t have metrics, and we don’t have categories.
And I think that this will be a real game changer.
So this is just one thing, but I think this is important.
So awareness leads to preparedness,
and preparedness means that you are kind of, ready
to basically, when the event happens, to protect the most vulnerable.
And there's a whole slew of actions
that cities are doing all around the world,
short-term things, to protect people during the heat waves.
For example, in Athens, we have created a smartphone app
that gives you personalized
and real-time risk assessment
and gives you, on a map,
risk assessments in relation to heat,
and gives you on a map where you can go to get cover,
where are the cool spaces, the nearest cool spaces.
New York has created this great buddy system
where people in the neighborhood keep on checking during heat waves
on people that are vulnerable in the neighborhood.
They also gave, I think a couple of years ago,
74,000 units of air conditioning for low-income seniors.
Sydney does this great thing,
which is that they divert energy from the industrial sector
to residential districts to avoid blackouts
during heat waves.
So these are some short-term things that we can do
and we've been doing.
But the real task at hand is redesigning our cities
to make our cities cooler
and thinking beyond air conditioning.
So before we started designing our buildings and our cities
and cooling them and heating them with fossil fuels,
architecture had incorporated centuries-long wisdom
for design solutions and materials
that were fine-tuned to the local climate conditions.
So thick walls with tiny openings
or well-placed windows high up in the building
that kind of move air from the bottom up and out
or outside shutters.
Shady and verdant internal courtyards with fountains
or outside walls that are whitewashed every spring
to reflect the hot summer heat,
the heat of the hot summers.
So compare these to our concrete,
steel and glass buildings that are air conditioned
and that have sealed windows
that basically make our cities into heat traps
compounding instead of solving the problem.
So, what we really need to do
is we need to radically rethink and redesign
our urban environments
away from the logic of modernity,
away from the logic of carbon modernity.
Carbon is there from the get go,
from the materials that we use for the types of construction,
from the way we use the buildings, we heat and cool them,
the way we eat, the way we consume,
the way we move around in our urban environments.
So we need to redesign our cities
beyond energy efficiency and cutting carbon emissions.
We need an urban design revolution,
a total paradigm shift
that probably needs to be led not by architects anymore,
but landscape architects
that know more about thermodynamics and soil
and the importance of soils for biodiversity
and all these things that can really bring about a real paradigm shift,
a revolution in design, a new type of urbanity
that actually is a different metabolic animal.
Our cities of the future will be different metabolic systems.
And we don't really know yet what this is going to look like,
but I think it’s going to be great, and it’s just the beginning.
But what we do know is that we really,
really urgently need to build resilience to our current climate conditions
at urban scale.
There are materials
and technologies that are currently being developed that will help,
but the main thing, the first and foremost and most important thing
for bringing down heat in cities is bringing nature into the urban fabric.
And this means a radical increase of trees, of tree coverage,
of biodiversity and of water in the surfaces of our cities
so that we can bring down the heat.
(Applause)
So this is the time, this is the decade,
and this means that cities have to really think
the interconnections and interdependencies
between different urban systems,
and they have to think of resources very carefully
and build backup systems
and redundancies, flexibility and diversity.
And think about sustainability and equity,
because this is how we build resilience in our cities.
And cities are already doing it and they’re changing.
And we're very much learning from each other
because for the first time, the last few decades,
cities belong in powerful urban networks
so we're kind of talking with each other and learning from each other.
Networks like Resilient Cities Network and C40 are really supporting cities.
And I'm going to give you a finish by giving you a few examples
of what cities have done,
and of course, I'm going to start from Athens.
So in Athens, we have this incredible Roman aqueduct,
a brilliant, ancient masterpiece
of design and engineering
that runs for 20 kilometers underground, totally invisible,
and still today moves enormous amounts of water
from the hills outside of Athens to the center of Athens.
The water is great, too, it's perfect for irrigation,
you don't need to do anything to it.
And for decades now,
we've been just throwing it into the sewage and then to the sea.
So now this urban aqueduct, this ancient monument,
is going to be used to build resilience and lower heat
by supporting urban nature for the modern city of Athens.
Another great example is Medellín, in Colombia.
Medellín, they created 36 green corridors,
a dense network of trees and flower beds
that has lowered temperatures four degrees Celsius in the city,
and it does a lot of other things,
ecosystemic services, like captures pollution
and noise pollution and water and soil erosion.
So all these things have really important ecosystemic services.
You probably know, Seoul in South Korea,
they dismantled a highway that was ten lanes long
and it had four lanes on top expressway,
to restore a stream underneath
and [they] created this blue corridor and green corridor, 3.6 miles long,
a continuous space for wildlife
and people to walk and bicycle,
that not only lowers temperatures,
they've measured that it goes up to 5.9 degrees Celsius,
that it lowers temperatures in that area,
But also it protects the city from flooding.
And, of course, it attracts thousands of visitors every day,
has created a lot of jobs
and has supported business development more than any other part of Seoul.
Paris is using the water of the Seine
to give free cooling to buildings around the river.
And finally, I'll finish with Melbourne in Australia
because they have created an incredible strategy
that's called Nature in the City Strategy,
where they've analyzed and think
how to bring together all of the levels of the ecosystem
from the soil and the fungi underneath
to the plants and the animals and the birds and the insects
and the frogs
and put into place all these actions
that will ensure that the urban environment,
that their kids will grow up, will be richer and much healthier.
So, what keeps me really excited about this work,
working to help cities cool down
and work against climate change,
is also that I feel that I'm really helping
create much more wonderful cities to live in.
So just think about this,
cranking up the air conditioning
is just not going to cut it.
Thank you.
(Applause)