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Time to 1.5 | 2 | This Most Excellent Canopy
Episode 2 • 8th February 2022 • Threshold • Auricle Productions
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Ulf Nilsson:

Threshold is made with the support of listeners

Ulf Nilsson:

like you. Join us@thresholdpodcast.org

Amy Martin:

When I was a kid, you could win a goldfish in a

Amy Martin:

bag at the carnival. Is that still the thing these traveling

Amy Martin:

fairs would come through every summer and set up rides like the

Amy Martin:

tilt a whirl and the silly silo in the middle of our little

Amy Martin:

town, we'd all go and buy tickets ride the rides and play

Amy Martin:

games like throwing rings over bottles or whatever. And if you

Amy Martin:

won, one of the prizes you could get was a goldfish in a plastic

Amy Martin:

bag. As I've been working on this season of Threshold, I keep

Amy Martin:

thinking about those goldfish, about how I am one. We all are

Amy Martin:

swimming around in a bubble of life giving air that we call the

Amy Martin:

atmosphere. It's a warm cushion protecting us from the Frozen

Amy Martin:

barrenness of space, and most of the gasses that make up that

Amy Martin:

cushion are in the first 10 miles. If we could defy gravity

Amy Martin:

and walk straight up away from the surface of the Earth, we'd

Amy Martin:

cross the bulk of the atmosphere in a couple of hours. And beyond

Amy Martin:

that thin membrane lies death. Cold, dark, emptiness. Our

Amy Martin:

relationship with the atmosphere might be more intimate than our

Amy Martin:

relationship with anything else on the planet, and maybe that's

Amy Martin:

why it's so hard to appreciate it. Just like the goldfish, it's

Amy Martin:

the water we're swimming in. But unlike the goldfish, we have the

Amy Martin:

capacity to understand our atmosphere, and I think this is

Amy Martin:

a part of the quest to limit global heating to 1.5 degrees

Amy Martin:

that often get skipped. The atmosphere is the central

Amy Martin:

character in the climate drama, but most of us have no idea what

Amy Martin:

it really is or how it works, how powerful the atmosphere is

Amy Martin:

and how fragile. So let's fix that. Let's spend an episode

Amy Martin:

getting better acquainted with our little cocoon of air. I've

Amy Martin:

recruited three guides for us.

Francina Dominguez:

My name is Francina Dominguez.

Hannah Wakeford:

I'm Hannah Wakeford.

Anjali Tripathi:

My name is Anjali Tripathi.

Amy Martin:

Francina Dominguez is an atmospheric scientist.

Amy Martin:

Hannah Wakeford and Anjali Tripathi are astrophysicists,

Amy Martin:

and they're going to help us explore the mystery and wonder

Amy Martin:

of our most excellent canopy, the atmosphere.

Francina Dominguez:

It's like underappreciated transparency.

Anjali Tripathi:

Our atmosphere is like a reservoir for life to

Anjali Tripathi:

flourish off of.

Matt:

We cannot negotiate with nature. We cannot negotiate with

Matt:

the planet.

Hannah Wakeford:

This planet will survive. It will reset

Hannah Wakeford:

itself. It will turn into a different atmosphere. We're not

Hannah Wakeford:

designed for that, and evolution is a lot slower than we'd like

Hannah Wakeford:

it to be.

Amy Martin:

The atmosphere is mysterious, almost by

Amy Martin:

definition. It's the word we use to describe something vague

Amy Martin:

lying in the background, the atmosphere in the room, the

Amy Martin:

atmosphere of the occasion. It's a mood, an undertone, an

Amy Martin:

invisible, certain something. We can't put a sign up in front of

Amy Martin:

the atmosphere and go visit it like a national park. We can't

Amy Martin:

stand on its shores and witness the damage we're doing to it

Amy Martin:

like on a beach after an oil spill. And I think that's partly

Amy Martin:

why we've been so slow to react to the climate crisis. I mean,

Amy Martin:

it's hard enough to get people to care about protecting a

Amy Martin:

beautiful mountain range or a charismatic wild animal. In this

Amy Martin:

case, we need to get deeply invested in the fate of

Amy Martin:

something that's almost the definition of intangible. We

Amy Martin:

spend our whole lives inside it, rarely thinking about it, but

Amy Martin:

pluck us out of our atmosphere, and we are as helpless and

Amy Martin:

gasping as a fish pulled out of a lake.

Francina Dominguez:

The first thing is just how beautiful it

Francina Dominguez:

is, right?

Amy Martin:

Francine Dominguez is a professor in Atmospheric

Amy Martin:

Sciences at the University of Illinois, at Urbana- Champagne.

Francina Dominguez:

If you sit down and look at a huge storm or

Francina Dominguez:

even fair weather clouds, the way that they move and morph is

Francina Dominguez:

just gorgeous.

Amy Martin:

And that beautiful movement has all kinds of really

Amy Martin:

important purposes

Hannah Wakeford:

Our atmosphere is responsible for everything.

Amy Martin:

Hannah Wakeford is an astrophysicist based at the

Amy Martin:

University of Bristol in the UK, and she says it's almost

Amy Martin:

impossible to overstate the importance of the Earth's

Amy Martin:

atmosphere.

Hannah Wakeford:

It is responsible for the water cycle.

Hannah Wakeford:

It is responsible for the recycling of carbon dioxide, and

Hannah Wakeford:

responsible for waves on the ocean and the circulation of

Hannah Wakeford:

Saharan dust around the planet. It transports biological

Hannah Wakeford:

material. It pollinates plants. The wind structure on our planet

Hannah Wakeford:

creates biomes at different latitudes which allow us to grow

Hannah Wakeford:

very different kinds of crops.

Amy Martin:

The atmosphere flows around the planet in the form of

Amy Martin:

wind and clouds and storms, transporting water and warmth

Amy Martin:

from place to place.

Francina Dominguez:

It's carrying essential ingredients

Francina Dominguez:

that make this mind boggling complexity of organisms

Francina Dominguez:

possible.

Amy Martin:

So if you were gonna try to compare the atmosphere to

Amy Martin:

something else on the planet, what would that be? Is there, is

Amy Martin:

there anything else that's kind of like the atmosphere?

Francina Dominguez:

The atmosphere? No, it's It's so

Francina Dominguez:

unique. It's like underappreciated transparency. I

Francina Dominguez:

think this underappreciated magical substance.

Hannah Wakeford:

There's just these really small things, these

Hannah Wakeford:

little nuances. But the more you look, the more you go, wow. How

Hannah Wakeford:

did I not know about this? How does this all fit together?

Hannah Wakeford:

It's, it's so infinitely complex.

Amy Martin:

And also so simple, as simple as breathing.

Amy Martin:

We take atmosphere into our bodies. Every inhalation and

Amy Martin:

exhalation we make is an interaction with it. It fills

Amy Martin:

our lungs, gets dissolved into our blood and races to our

Amy Martin:

hearts, where it's then pumped out to feed our cells with the

Amy Martin:

oxygen they need to move our muscles, fight off disease,

Amy Martin:

digest our food, generate thoughts. Every piece of art

Amy Martin:

we've ever made, every structure we've ever built, every song

Amy Martin:

we've ever sung, every word we have ever uttered, has been a

Amy Martin:

collaboration with the atmosphere we can live for a

Amy Martin:

little while without water. We can live even longer without

Amy Martin:

food. But when we lose our ability to take in the

Amy Martin:

atmosphere, when that collaborative dance between us

Amy Martin:

and the air breaks down, we die almost instantly.

Anjali Tripathi:

Our atmosphere is like a reservoir for life to

Anjali Tripathi:

flourish off of, and that reservoir dictates a lot of what

Anjali Tripathi:

happens on the planet.

Amy Martin:

Astrophysicist Anjali Tripathi is affiliated

Amy Martin:

with the Harvard Smithsonian Center for Astrophysics.

Anjali Tripathi:

I would encourage you to lie back on the

Anjali Tripathi:

grass and stare up at the sky. Take a deep breath and look at

Anjali Tripathi:

the clouds passing by, because that ability and that

Anjali Tripathi:

opportunity is, I would argue, underappreciated in our daily

Anjali Tripathi:

lives.

Anjali Tripathi:

Even if we go and move off to another nearby planet, we're

Anjali Tripathi:

gonna have to do a lot of work to make that atmosphere into

Anjali Tripathi:

something that we can work with in the same way. Sci fi

Anjali Tripathi:

literature is rife with options of what you could do in those

Anjali Tripathi:

situations. None of them are take spaceship to Planet X, get

Anjali Tripathi:

out, enjoy life. Done. It's not that simple.

Amy Martin:

And we don't only need the atmosphere to breathe,

Amy Martin:

we also need it for protection.

Anjali Tripathi:

Space is a pretty hostile place.

Amy Martin:

For one thing, it's really, really cold. Baseline

Amy Martin:

space temperatures are around negative 455 degrees Fahrenheit,

Amy Martin:

or negative 270 degrees Celsius. So, cold. And even though we

Amy Martin:

can't see it, there's a lot of stuff flying around up there

Amy Martin:

that can hurt us. Stars exploding in faraway galaxies

Amy Martin:

send charged particles hurtling through space, and those

Amy Martin:

particles can damage our cells. Our own star, the Sun, produces

Amy Martin:

some unfriendly particles as well. Anjali says that's one of

Amy Martin:

the reasons she thinks of the cushion of air around our.

Amy Martin:

Planet as a safety blanket.

Anjali Tripathi:

It's also a safety blanket because it takes

Anjali Tripathi:

the heat quite literally for us, when we have impacts.

Amy Martin:

All kinds of space debris burns up in our

Amy Martin:

atmosphere before it hits the ground, saving us from having a

Amy Martin:

surface dominated by craters the way the Moon and Mars are. But

Amy Martin:

what is that safety blanket actually made of? What is an

Amy Martin:

atmosphere?

Hannah Wakeford:

An atmosphere is a collection of gasses that

Hannah Wakeford:

are bound by gravity to a planet.

Francina Dominguez:

They're held by the gravitational pull

Francina Dominguez:

because they have mass, and it is counterintuitive that we are

Francina Dominguez:

basically underneath this ocean of air. I'm appropriating this

Francina Dominguez:

from the book, An Ocean of Air by Gabrielle Walker. So it's a

Francina Dominguez:

beautiful book at the beginning, it talks about this, that it's a

Francina Dominguez:

non intuitive concept, that the air has weight, and it actually

Francina Dominguez:

has a ton of weight.

Amy Martin:

Just like when a scuba diver goes underwater and

Amy Martin:

can feel the weight of that water pressing harder as they go

Amy Martin:

deeper, we're in an ocean of air. Even though we can't see

Amy Martin:

the atmosphere the way we can see the water in the ocean, it's

Amy Martin:

still a substance that can be set on a scale and Wade, it's

Amy Martin:

about 300 miles thick from top to bottom, but the bulk of it is

Amy Martin:

in the first 10 miles closest to Earth.

Francina Dominguez:

It took humanity 1000s of years to

Francina Dominguez:

figure out that air had mass. It's completely non intuitive.

Francina Dominguez:

And then imagine, then afterwards, trying to understand

Francina Dominguez:

that air was made of different ingredients, right? It's not

Francina Dominguez:

intuitive at all.

Amy Martin:

But not every planetary body has an

Amy Martin:

atmosphere. For instance, the moon basically has none. So how

Amy Martin:

did our atmosphere come to be?

Hannah Wakeford:

So the earth is thought to have always had some

Hannah Wakeford:

kind of atmosphere, but we are either on our second or third or

Hannah Wakeford:

fourth atmosphere, depending on which combination of things you

Hannah Wakeford:

would say defines a break in what kind of atmosphere you

Hannah Wakeford:

have.

Amy Martin:

About four and a half billion years ago, when the

Amy Martin:

earth was born, our atmosphere was mostly helium and hydrogen.

Hannah Wakeford:

So when we first formed as a planet, we

Hannah Wakeford:

would have been very hot. It would have been a kind of molten

Hannah Wakeford:

lava world. And then we actually went for a cataclysmic event

Hannah Wakeford:

when the Moon formed. This would have disrupted the atmosphere

Hannah Wakeford:

completely, and it would have reformed. But our secondary

Hannah Wakeford:

atmosphere came when volcanoes let off gas. So the early Earth

Hannah Wakeford:

was highly volcanic, highly active world. And then over

Hannah Wakeford:

time, something happened, and about 2.2 billion years ago, the

Hannah Wakeford:

CO two dropped, and the oxygen 02 arose it's called the Great

Hannah Wakeford:

oxygenation event, where oxygen kind of came about in our

Hannah Wakeford:

atmosphere as the second most dominant component.

Francina Dominguez:

And this was a huge shifting point in the

Francina Dominguez:

earth's history.

Amy Martin:

It started with cyanobacteria, some of the first

Amy Martin:

organisms on our planet that were able to photosynthesize,

Amy Martin:

which meant they were essentially exhaling oxygen.

Francina Dominguez:

So they're in the ocean, and the oxygen is

Francina Dominguez:

starting to accumulate in the ocean water and in the rocks,

Francina Dominguez:

and little by little, this oxygen starts to trickle into

Francina Dominguez:

the atmosphere, okay, but this is very slow, right? Billion

Francina Dominguez:

years this is in the making. Slowly but surely, you're having

Francina Dominguez:

this trickling of oxygen into the atmosphere. And about 600

Francina Dominguez:

million years ago, we hit this threshold, which is about 5%

Francina Dominguez:

oxygen, and this just is kind of like a burst of of life, where

Francina Dominguez:

you now can have multicellular organisms, now you have

Francina Dominguez:

organisms with eyes and teeth and that can move. So it's this,

Francina Dominguez:

this kind of threshold in the amount of oxygen that enables

Francina Dominguez:

complex life to form.

Amy Martin:

Wow. So it took a long time between beginning to

Amy Martin:

release oxygen into the air and getting to complex life. Like a

Amy Martin:

really long time.

Francina Dominguez:

Yes, a really long time, a really long

Francina Dominguez:

time. You. Yeah.

Amy Martin:

So the Earth's atmosphere allowed very simple

Amy Martin:

life forms to emerge, and then those life forms themselves

Amy Martin:

actually changed the chemistry of the canopy of air around the

Amy Martin:

planet, adding more and more oxygen, bit by tiny bit, which

Amy Martin:

allowed more and more complex life forms to evolve.

Hannah Wakeford:

So there's so many changes. There is an

Hannah Wakeford:

evolution of a planet through time, and you can see that

Hannah Wakeford:

imprinted in the planet's atmosphere.

Amy Martin:

Today, our atmosphere is about 78% nitrogen

Amy Martin:

and 21% oxygen.

Anjali Tripathi:

That only leaves about 1% left for

Anjali Tripathi:

everything else.

Anjali Tripathi:

it, and said, Oh, what's this leftover piece?

Anjali Tripathi:

Oh, okay, I guess we'll call that argon. And then, you know,

Anjali Tripathi:

at tiny fractions, maybe four hundredths of a percent, we have

Anjali Tripathi:

carbon dioxide and other gasses in the atmosphere. So when you

Anjali Tripathi:

think about the atmosphere, really, we're saying this

Anjali Tripathi:

nitrogen, oxygen, argon, bath that is a veneer around our

Anjali Tripathi:

planet.

Amy Martin:

Did you catch that? Carbon dioxide, the planet

Amy Martin:

warming gas that's causing so much trouble for us these days

Amy Martin:

is just a tiny fraction of the total atmospheric brew.

Hannah Wakeford:

That percentage is somewhere around 0.041 at the

Hannah Wakeford:

moment.

Amy Martin:

It's so small compared to 78% nitrogen.

Hannah Wakeford:

It's so small.

Amy Martin:

So I'm guessing you might be wondering what I was

Amy Martin:

wondering at this point. If carbon dioxide is such a teeny,

Amy Martin:

tiny portion of the atmosphere, how can it be so important?

Amy Martin:

We'll find out after the break.

Amy Martin:

I want to tell you about another podcast you might enjoy. It's

Amy Martin:

called The Wild with Chris Morgan, and it explores the

Amy Martin:

often fraught relationship between humans and wildlife. On

Amy Martin:

this season of The Wild, Chris introduces you to some of the

Amy Martin:

passionate people who are making a difference for our planet,

Amy Martin:

from icy volcanoes to forests in Portugal, meet the people who

Amy Martin:

are witnesses to our wild spaces. Join the adventures of

Amy Martin:

The Wild to hear stories about the complexity and resiliency of

Amy Martin:

nature and the people who work in it, love it and protect it.

Amy Martin:

Available wherever you listen to podcasts.

Amy Martin:

Welcome back to Threshold. I'm Amy Martin, and before the

Amy Martin:

break, we were talking about how carbon dioxide makes up just a

Amy Martin:

tiny percentage of our overall atmosphere, less than 1%. So how

Amy Martin:

is it possible that having less than 1% of anything in the air

Amy Martin:

could be such a big deal? Atmospheric scientist Francine

Amy Martin:

Dominguez says one way to start to wrap our heads around that is

Amy Martin:

to imagine our planet without any atmosphere.

Francina Dominguez:

The Earth would be a ball of ice.

Amy Martin:

She says, if we had no atmosphere at all, the

Amy Martin:

Earth's average temperature would be negative 18 degrees

Amy Martin:

Celsius. That's a little below zero Fahrenheit, so way below

Amy Martin:

freezing. But-

Francina Dominguez:

In reality, we're at about 15 Celsius.

Amy Martin:

-that's around 60 degrees Fahrenheit.

Francina Dominguez:

That's our average temperature. This huge

Francina Dominguez:

difference right between frigid conditions that could not

Francina Dominguez:

sustain life to balmy, not too hot, not too cold conditions

Francina Dominguez:

that enable these spectacular life forms.

Amy Martin:

And that difference between a completely frozen

Amy Martin:

earth and the much warmer earth we actually have is the

Amy Martin:

greenhouse effect, the special way that carbon dioxide and a

Amy Martin:

few other trace gasses trap the heat around our planet. I'm

Amy Martin:

guessing most of us never heard about the greenhouse effect

Amy Martin:

until we started hearing that it was a problem. But actually we

Amy Martin:

need a certain amount of greenhouse gasses, like water

Amy Martin:

vapor and CO two in our atmosphere. So the greenhouse

Amy Martin:

effect, in and of itself, is not a bad thing, but it is a

Amy Martin:

delicate thing. So how does it work, really? We all know carbon

Amy Martin:

dioxide is classified as a greenhouse gas, but how does it

Amy Martin:

trap heat around the planet? Well. Much more abundant gasses

Amy Martin:

like nitrogen and oxygen, don't? I asked Francina to explain it

Amy Martin:

to me, not at the PhD in atmospheric sciences level, but

Amy Martin:

just with the goal of understanding the basics of the

Amy Martin:

greenhouse effect well enough that I could explain it to

Amy Martin:

someone else without googling anything. And she started with

Amy Martin:

radiation.

Francina Dominguez:

All objects emit radiation, and the

Francina Dominguez:

wavelength depends on the temperature of the object. So

Francina Dominguez:

the sun, which is super hot, emits primarily in the short

Francina Dominguez:

wave, but the Earth, which is much cooler than the sun emits

Francina Dominguez:

primarily in the long wave

Amy Martin:

So the energy flowing into the Earth's

Amy Martin:

atmosphere from the sun comes mostly as short wave radiation,

Amy Martin:

and then the earth bounces some of that energy back out into

Amy Martin:

space, mostly as long wave radiation. Francina says it's

Amy Martin:

this slower, cooler radiation emitted by the planet itself

Amy Martin:

that really matters when it comes to the greenhouse effect,

Amy Martin:

because that long wave radiation behaves differently when it

Amy Martin:

meets different gasses in our atmosphere. When it meets oxygen

Amy Martin:

and nitrogen, it just keeps on going. But when long wave

Amy Martin:

radiation meets up with carbon dioxide and water vapor,

Amy Martin:

something different happens.

Francina Dominguez:

So what sets water vapor and CO2 apart from,

Francina Dominguez:

say, nitrogen and oxygen, which is what, again, most of our

Francina Dominguez:

atmosphere is made of, is that they're kind of lopsided.

Francina Dominguez:

They're not completely symmetrical, and they

Francina Dominguez:

essentially jiggle.

Amy Martin:

Because of how these molecules are shaped. They move

Amy Martin:

differently than nitrogen or oxygen. They're much more

Amy Martin:

creative dancers, and that causes them to block some of the

Amy Martin:

long wave radiation flowing up and away from the planet. You

Amy Martin:

could think of these lopsided, jiggling molecules of CO2 and

Amy Martin:

water vapor as molecular speed bumps, or maybe sponges.

Francina Dominguez:

When the radiation hits them, it gets

Francina Dominguez:

absorbed, and that air is gonna heat up, essentially, because

Francina Dominguez:

it's absorbing this radiation.

Amy Martin:

That warmth then radiates back down toward the

Amy Martin:

surface, and the whole system gets a little hotter, the land,

Amy Martin:

the water, the air. So that's the greenhouse effect, in a

Amy Martin:

nutshell, dancing asymmetrical molecules absorbing long wave

Amy Martin:

radiation from the earth.

Francina Dominguez:

It's like a blanket. They're forming, this

Francina Dominguez:

blanket over us that's kind of keeping our heat from escaping,

Francina Dominguez:

because it's being kind of reradiated back to us.

Amy Martin:

And at the same time that this blanket is preventing

Amy Martin:

some of our long wave radiation from escaping, which helps to

Amy Martin:

keep us warm, it's also blocking some of the very highest

Amy Martin:

intensity radiation from the sun, which would be deadly for

Amy Martin:

living things if it made it down to the surface of the planet. So

Amy Martin:

the atmosphere is doing all kinds of things for us all at

Amy Martin:

once.

Francina Dominguez:

So at the longest wavelengths, the

Francina Dominguez:

atmosphere keeps us warm and does not allow all of that

Francina Dominguez:

energy just to be lost to space. So think of it as a blanket. But

Francina Dominguez:

at the highest at the very high energy wavelength, the

Francina Dominguez:

atmosphere is a shield, because it protects us from this

Francina Dominguez:

shortwave, high energy radiation. So a shield and a

Francina Dominguez:

blanket.

Amy Martin:

It's like a magic blanket.

Francina Dominguez:

It's like a magic blanket, yes, so yeah.

Amy Martin:

And again, the part of that blanket that's doing the

Amy Martin:

most to keep us warm is the smallest part, the less than one

Amy Martin:

half of 1% of the atmosphere that's made up of carbon dioxide

Amy Martin:

and other trace gasses. These lopsided CO2 molecules interact

Amy Martin:

so powerfully with the Earth's long wave radiation that adding

Amy Martin:

just a few more of them can radically change the climate.

Amy Martin:

They're like salt in the atmospheric soup, a tiny

Amy Martin:

proportion of the hole with a huge effect.

Francina Dominguez:

Trace amounts of these gasses make the

Francina Dominguez:

difference between a snowball Earth and the Earth that we

Francina Dominguez:

currently have. So very small amounts make a huge difference.

Amy Martin:

The greenhouse effect is a natural process of

Amy Martin:

our atmosphere. We didn't create it, but we can mess it up by

Amy Martin:

treating the atmosphere like a sewer, as a place where we can

Amy Martin:

just thoughtlessly dump heat trapping gasses. We're running a

Amy Martin:

very dangerous chemistry experiment.

Francina Dominguez:

I guess we cannot say it any clearer in the

Francina Dominguez:

sense that we know we're modifying the atmosphere in a

Francina Dominguez:

way that's detrimental for all living species. We've known this

Francina Dominguez:

for decades. It's a matter of us realizing that if we continue on

Francina Dominguez:

this path, the consequences are gonna be just mind boggling.

Hannah Wakeford:

Thing with the Earth's climate is there's these

Hannah Wakeford:

things called feedback loops.

Amy Martin:

Hannah Wakeford.

Hannah Wakeford:

And there's not just one feedback it's not just

Hannah Wakeford:

about having greenhouse gasses in your atmosphere. It's about

Hannah Wakeford:

how much ice have you got, how much light is being reflected,

Hannah Wakeford:

how many clouds are you making? So it's all about how these

Hannah Wakeford:

different processes and these feedback loops interact with

Amy Martin:

To take just one example of that, if you listened

Amy Martin:

each other.

Amy Martin:

to Season Two of our show, you already know that our CO2

Amy Martin:

emissions are helping to thaw out frozen soil called

Amy Martin:

permafrost, and then that soil releases more greenhouse gasses

Amy Martin:

as it warms up, which leads to more warming, which leads to

Amy Martin:

more permafrost thaw, etc. The extra carbon dioxide that we're

Amy Martin:

adding to the air is kind of like kindling that can ignite

Amy Martin:

these much bigger fires in other parts of the Earth's

Amy Martin:

interconnected systems.

Hannah Wakeford:

And if we hit a tipping point on any one of

Hannah Wakeford:

those, it can send other ones into a spiral where they can't

Hannah Wakeford:

counter it anymore. And that's the biggest problem with CO2. It

Hannah Wakeford:

is adding to a feedback mechanism that we can't counter.

Amy Martin:

And if we want to see atmospheric feedbacks that

Amy Martin:

make life next to impossible, we don't have to look very far.

Hannah Wakeford:

We can look to Venus. It is not nice to be on

Hannah Wakeford:

the surface of Venus.

Amy Martin:

The atmosphere of Venus is incredibly heavy,

Amy Martin:

almost 100 times heavier than Earth's.

Anjali Tripathi:

It would literally be crushing you.

Amy Martin:

That's Anjali Tripathi again, and she says, in

Amy Martin:

addition to smashing you with its atmospheric pressure, Venus

Amy Martin:

would burn you alive.

Anjali Tripathi:

And so you can think about it as the same

Anjali Tripathi:

temperature as maybe a wood fired brick oven for making

Anjali Tripathi:

pizza. That's what it would feel like to be on Venus. So lead

Anjali Tripathi:

would melt.

Amy Martin:

So why is the Venusian atmosphere so heavy and

Amy Martin:

hot? Well, it's closer to the Sun than the Earth, but that

Amy Martin:

doesn't fully explain the difference. Scientists think

Amy Martin:

that Venus likely experienced a runaway greenhouse effect, CO2

Amy Martin:

and water vapor trapped heat around the planet, and that heat

Amy Martin:

led to the release of more greenhouse gasses, and now the

Amy Martin:

planet is uninhabitable, at least to any creatures that are

Amy Martin:

anything like us.

Hannah Wakeford:

Venus is about the same size in terms of radius

Hannah Wakeford:

and mass as the Earth. We're sometimes called twins, and

Hannah Wakeford:

Venus is the evil twin, because it's such a horrible place to

Hannah Wakeford:

be.

Amy Martin:

The process of atmospheres forming and changing

Amy Martin:

is super complex, and there are countless factors at play here,

Amy Martin:

but still, it's worth noting that our nearest neighbor and

Amy Martin:

our closest planetary twin ended up with a hellscape of an

Amy Martin:

atmosphere because of a greenhouse effect gone haywire.

Anjali Tripathi:

It just makes you stop and wonder and

Anjali Tripathi:

appreciate the fact that you've got everything finely tuned in a

Anjali Tripathi:

way that it's working for us because it seems like it's so

Anjali Tripathi:

much harder for that to happen than not to.

Amy Martin:

Not only is the atmosphere working for us, we

Amy Martin:

work the way we do because of the atmosphere. As just one

Amy Martin:

example, take the way we see. There's all kinds of

Amy Martin:

electromagnetic energy flying around us, gamma rays, infrared

Amy Martin:

rays, radio waves, but we can only see a narrow band of that

Amy Martin:

energy. That's the window that we call "visible light." But why

Amy Martin:

is that particular range of waves visible to us? The

Amy Martin:

atmosphere. Francina Dominguez says what we call visible light

Amy Martin:

is just the stuff that doesn't get filtered out by the air

Amy Martin:

around us.

Francina Dominguez:

These are the wavelengths that our

Francina Dominguez:

atmosphere let's pass, and our sensors have adapted to those

Francina Dominguez:

exact wavelengths.

Amy Martin:

And if we'd evolved in a different sort of

Amy Martin:

atmosphere, our eyes would work differently. We'd call some

Amy Martin:

other part of the spectrum "visible." That's pretty mind

Amy Martin:

blowing to contemplate, really, this amorphous stuff that we

Amy Martin:

rarely think about, the air, actually sculpted the shape and

Amy Martin:

function of our bodies.

Francina Dominguez:

We see in these wavelengths that are

Francina Dominguez:

transmitted through the atmosphere. So that's pretty

Francina Dominguez:

cool.

Amy Martin:

We might want to keep this in mind as we dream

Amy Martin:

about moving to a different planet someday. You can take us

Amy Martin:

out of Earth's atmosphere, but you can't take Earth's

Amy Martin:

atmosphere out of us. It made us who we are, and no matter where

Amy Martin:

we go, This atmosphere is. Our true home. If we ever do try to

Amy Martin:

make a life for ourselves on Mars or anywhere else, we'll

Amy Martin:

have to spend a lot of time and money generating an atmosphere

Amy Martin:

using Earth as a blueprint. We truly will be like the goldfish

Amy Martin:

in the baggies then either walking around in space suits

Amy Martin:

with portable atmospheres or living inside shelters that

Amy Martin:

recreate what we have here. If that ever happens, I think

Amy Martin:

people will look with longing and envy at the freedom we have

Amy Martin:

now, walking around unencumbered in an atmosphere that works for

Amy Martin:

us without giving it a second thought.

Anjali Tripathi:

You know, our atmosphere will always be

Anjali Tripathi:

intrinsically special because it is our atmosphere.

Amy Martin:

Anjali tripathi's area of expertise is actually

Amy Martin:

atmospheres on planets outside of our solar system, called

Amy Martin:

exoplanets. And she says, so far, we haven't found any

Amy Martin:

planets anywhere with atmospheres that match our own.

Anjali Tripathi:

I don't like to say that everything we see here

Anjali Tripathi:

could not happen again anywhere else, because, of course, the

Anjali Tripathi:

laws of physics are the same elsewhere, but we keep looking

Anjali Tripathi:

and looking and nothing looks the same. It's like people's

Anjali Tripathi:

faces, right? No two are the same. But it is also my hope

Anjali Tripathi:

that our atmosphere is not that special in terms of how common

Anjali Tripathi:

it is throughout the universe, because there should be these

Anjali Tripathi:

ingredients other place. Like it shouldn't be, this is the one

Anjali Tripathi:

place in the universe where there was enough disorder to

Anjali Tripathi:

kick life into motion, because, again, life is actually

Anjali Tripathi:

something that needs to come out of a little bit of chaos. If

Anjali Tripathi:

there's too much order, probably not everything comes together in

Anjali Tripathi:

the right way. So it's my hope that other inhabitants of the

Anjali Tripathi:

universe can enjoy an atmosphere like our own, because we do find

Anjali Tripathi:

it to be pretty special.

Amy Martin:

Maybe some alien astrophysicists on a distant

Amy Martin:

planet are looking through their telescopes at our atmosphere,

Amy Martin:

wondering who we are or if we exist at all. Maybe they're

Amy Martin:

going through the same kind of phase we are, a time of

Amy Martin:

realization and reckoning with our impact on the atmosphere and

Amy Martin:

the planet as a whole. Maybe this is a rubicon all

Amy Martin:

technologically advanced species cross or don't.

Hannah Wakeford:

This planet will survive. It will reset

Hannah Wakeford:

itself. It will turn into a different atmosphere. It will

Hannah Wakeford:

come up with a CO2 rich atmosphere with lots and lots of

Hannah Wakeford:

clouds all the way up. But we're not designed for that, and

Hannah Wakeford:

evolution is a lot slower than we'd like it to be.

Amy Martin:

If we are going to limit global heating to one and

Amy Martin:

a half degrees Celsius over pre industrial temperatures, we need

Amy Martin:

to get passionate about the atmosphere. To fall in love with

Amy Martin:

it, just like we fall in love with forests and rivers and

Amy Martin:

creatures down here on the surface of our planet.

Francina Dominguez:

The beauty and the complexity of the living

Francina Dominguez:

organisms on Earth is made possible by this interaction of

Francina Dominguez:

these three things, essentially the sun, the atmosphere and the

Francina Dominguez:

earth interacting together to create all of this amazing

Francina Dominguez:

beauty and complexity.

Amy Martin:

It's almost like the atmosphere serves as connective

Amy Martin:

tissue between the Sun and the Earth, and although that tissue

Amy Martin:

is extremely multifaceted and strong, it's also extremely

Amy Martin:

sensitive. It's protecting us, so we need to protect it.

Francina Dominguez:

We can do this, and there's just no reason

Francina Dominguez:

not to do it. We can't wait. We can start right now.

Amy Martin:

The climate crisis is teaching us that we have a

Amy Martin:

power that we didn't ask for, and in many ways, do not want.

Amy Martin:

The power to fundamentally change the atmosphere and

Amy Martin:

therefore the future of life on the planet. That is a heavy

Amy Martin:

burden to bear, but we can't turn back time or wish this

Amy Martin:

power away. The choice before us is whether or not we'll take

Amy Martin:

responsibility for it.

Anjali Tripathi:

Part of what's making our atmosphere special is

Anjali Tripathi:

that we're here to appreciate it, but it's also special that

Anjali Tripathi:

we then have that ability to do something about it and shape its

Anjali Tripathi:

future.

Amy Martin:

Picture all of us earthlings, nestled in here

Amy Martin:

together under this life giving, climate stabilizing, magical

Amy Martin:

blanket, this most excellent canopy, this ocean of air that

Amy Martin:

birthed us and made us who we are. Sometimes we talk about the

Amy Martin:

need to save the planet, but I think we've got it backwards. If

Amy Martin:

we manage to keep living and learning and evolving here in

Amy Martin:

the black and barren vastness of space, it'll be because our

Amy Martin:

atmosphere continues to save us.

Amy Martin:

In our next episode, we're taking a trip to the birthplace

Amy Martin:

of the Industrial Revolution and the climate crisis.

Matt:

So this whole idea of King coal, you know? I mean, you

Matt:

absolutely can put that here. That's the legacy.

Amy Martin:

Travel with us to 18th century England. Next time

Amy Martin:

on Threshold.

Andy:

I'm Andy calling from Madison, Wisconsin, reporting

Andy:

for this season of Threshold was funded by the Park Foundation,

Andy:

the High Stakes Foundation, the Pleiades Foundation, NewsMatch,

Andy:

the Llewellyn Foundation, Montana Public Radio and

Andy:

listeners. This work depends on people who believe in it and

Andy:

choose to support it. People like you. Join our community at

Andy:

thresholdpodcast.org

Amy Martin:

This episode of Threshold was produced and

Amy Martin:

reported by me, Amy Martin, with help from Todd Sickafoose, Nick

Amy Martin:

Mott and Erika Janik. The music is by Todd Sickafoose. The rest

Amy Martin:

of the Threshold team includes Eva Kalea, Talia Farnsworth,

Amy Martin:

Shola Lawal, Caysi Simpson, and Deneen Weiske. Thanks to Sarah

Amy Martin:

Sneath, Sally Deng, Maggy Contreras, Hana Carey, Dan

Amy Martin:

Carreno, Luca Borghese, Julia Barry, Kara Cromwell, Katie

Amy Martin:

deFusco, Caroline Kurtz and Gabby Piamonte. Special thanks

Amy Martin:

to Arianna Varuolo-Clark and Ulf Nilsson. And extra special

Amy Martin:

thanks to listeners who sent in recordings of breath and wind

Amy Martin:

and frogs and elephant seals used in this episode.

Amy Martin:

Christopher McAllister, Anna Taugher, Claudia Streijek, Evan

Amy Martin:

Levy, Jürgen Morgenstern and Shelly Eisenrich. These are just

Amy Martin:

some of the listeners who participated in our Audio Mosaic

Amy Martin:

project. And actually, that project is still happening. If

Amy Martin:

you'd like to submit a recording that might end up in this season

Amy Martin:

of our show, go to thresholdpodcast.org and look

Amy Martin:

for the button that says Audio mosaic Project, again, That's

Amy Martin:

thresholdpodcast.org.

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