The impacts of climate change are so vast
that it's impossible to predict
exactly how it's gonna play out, right?
But there are two things that we can be pretty sure of.
One, every time it snows anywhere in the world
someone's uncles gonna be like hm,
what happened to global warming?
And two, the hottest year ever recorded will likely
be whatever year it currently is.
Otherwise, we would've called our show something else.
In the coming years.
Extreme heat will impact everything
in our world from microorganisms to geopolitics.
But in this episode
I wanna focus on how it'll impact our bodies.
Trust me, I'm a doctor.
Well, I was a doctor on TV.
When we get too hot
and I tell you this is a non-medical doctor
our body cools itself by evaporating sweat.
And if we can't sweat, it heats up.
And if it heats up too much, we die.
That simple, harsh fact is gonna completely
reshape our world over the coming decades.
And to understand why we need to understand something
called the wet bulb temperature.
Now, basically it's a combination
of heat and humidity that's measured
by a thermometer bulb wrapped in a wet cloth.
That's the wet bulb.
If the air is dry, the water like our sweat evaporates
off the cloth, which cools the thermometer.
If the air is really humid
the water like our sweat can't evaporate.
So the temperature stays where it is.
Dry heat is less dangerous
because the human body can sweat and adapt its temperature.
But at a wet bulb temperature of just 35 degrees Celsius
or 95 degrees Fahrenheit, the body can no longer adapt.
It overheats and technical term, you die.
Now, thankfully, that level of heat
and humidity is still pretty rare for now.
But by 2050, NASA climate models show that South Asia
the Persian Gulf and the Red Sea
will start hitting wet bulb temperatures
that could make those areas increasingly uninhabitable.
And by around 2070, the same thing will likely
happen in Arkansas, Missouri, and Iowa.
Even now, extreme heat is killing hundreds
of thousands of people around the world each year.
If humans wanna stick around, we need to adapt.
We need to think about the future of cooling.
When it comes to staying cool, we have several options.
For example, we could just dress in lighter clothing.
But here in America when a heat wave hits
the first thing we usually do is turn
on the air conditioner.
Unfortunately, if that AC is hooked to a dirty grid
we're effectively cooling the indoors
by heating the outdoors.
Air conditioners use about 10%
of all electricity produced in the US
which releases about 117 million tons of CO2 a year.
Meanwhile
in poorer countries where it's getting especially hot
thanks to rich country's decades of fossil fuel emissions
air conditioners are often financially out of reach.
But as economies in the global south grow
that will change.
By mid-century, about two-thirds
of the world's households are expected to have
air conditioners with China, India, and Indonesia
accounting for roughly half that.
That demand is obviously completely understandable
and it'll put an enormous strain on electrical capacity.
That means more power outages and a huge spike in emissions.
So if we wanna avoid serious climate blowback
humans need to rethink how we keep cool.
We could use materials and designs that optimize homes
for cooling or design urban landscapes with more vegetation
and water to lower temperatures of entire neighborhoods
and don't sleep on fans.
Fans use 30 to 50 times less energy than air conditioning.
They also allow our bodies to better acclimatize
to the heat.
And obviously, if you wanna be a fashion icon
you can just build them directly into your jacket.
In the commercial space
one option favored by green designers are cool roofs.
I know these sound
like roofs that go to Burning Man every year.
And whenever you hang out, they won't shut
up about Burning Man, which makes you even more confident.
You will never go
to Burning Man with them ever in your life.
But in fact, cool roofs are roofs that reflect the sun.
They're a climate friendly alternative
to traditional air conditioning
which is actually pretty cool.
But I'm still not gonna burning man.
Cool roofs are starting to be embraced all over the world
but can they actually make a difference?
We went to see one of them up close
in Madrid at the world's second largest fish market.