on a trip to see where my family came from.

That trip was the first time that I rode in an airplane,

and the first time that I got stuck in an airport.

We've been waiting here for 9 hours now!

Air travel is one of the great privileges of living in this century.

And the number of air passengers

is expected to double in the next 20 years.

There's just one problem.

Aviation runs on oil, which contributes to global climate change.

And there's not a good alternative yet.

So individual consumers were left wondering

about their own responsibility.

These blankets represent arctic sea ice.

Alex: How many polar bears did Cleo kill?

Shame arises when our values don't line up with our actions.

Oh, this is so embarrassing.

Joss: So, knowing what we know about the climate crisis,

is it wrong to fly?

( theme music playing )

Okay, I want you guys to think back on the past year of your lives

and remember all of the flights you took,

both for work and for personal trips.

I have a marker for each of you.

I want you to draw all of those flights on these maps.

- ( Alex chuckles ) - Amazing.

- Let's see. - A work trip for a story.

- Cleo: DC to Detroit. - New York to New Orleans.

So, this flight right here is a trip that I took to Ireland this year,

and on the way back, we flew over the southern tip of Greenland.

And I had the window seat.

And when I looked out the window,

this is what I saw.

That is a melting ice sheet.

It's probably something I would never see

except for in a plane like this.

But the plane that I was flying in is one of the reasons

that that ice was melting in the first place.

Because air travel accounts for about 5%

of man-made global warming in a year.

- Cleo: Whoa. - Joss: And that impact will only increase

as more and more people in Asia to take to the skies.

Okay, well, I have all of your flight data.

- Alex: Yeah. - Cleo: Uh-oh.

I'm going to be running some calculations on this,

and I will be bothering you all very soon.

- Okay. - All right.

- Okay? All right. - All right.

( music playing )

Everyone flies for different reasons.

The four of us, we took 84 flights in the past year,

and almost half of those were for work.

The best way to find out what impact that has on the climate

is to use an online calculator

that measures the carbon footprint of each flight.

( music playing )

They ask about your connections because nonstop flights

typically use fuel more efficiently.

Something like a quarter of emissions

are from take off and landing alone,

so you don't want to do that twice

if you don't have to.

They also ask whether you flew economy,

business class, or first class,

because if you're taking up more space on the plane,

you're responsible for more of the fuel use.

The folks in first class

are causing about five times the emissions

of the economy passengers.

Tsk, tsk, tsk.

So, all of our flights led up to the equivalent

of 36.7 metric tons of CO2.

It's kinda hard to know what that means

because CO2 is invisible.

But there was a report published that shows us

how we can translate our CO2 emissions

into actual square meters of melted arctic sea ice.

What we find, I mean, that basically the observed sea ice loss

is very linearly related

to how much CO2 we keep adding to the atmosphere,

such that for about, um, every metric ton of CO2

we add to the atmosphere,

we melt another three square meters of sea ice.

You know, whenever I fly from London to New York City, for example,

that's equivalent to about a metric ton of CO2.

So then I would melt about three square meters every time I flew.

So, basically, the size of a large dinner table, I guess.

Where's Joss?

Here's Alex's.

Where are we going?

I have no idea.

Do you guys know where we're going?

- No. - I have a pretty good guess.

I heard a lot of talk about blankets.

- Yeah, yeah, yeah. - Like picnic blankets?

- Mm. - Is there food there, is what I'm wondering.

Christophe: I don't think there is gonna be food.

No?

Welcome to the park.

How long have you been here?

I spent the night here.

- Oh, nice. - Oh, no.

- Not really. - At least you have blankets.

Yeah.

You ready to have some fun?

Uh, y-- I think so.

Okay, so, this morning

we're gonna be using our imagination.

So, these blankets are arctic sea ice.

And of course they're just blankets

that we're gonna be donating to Providence House

here in Brooklyn when we're done.

- Nice. - But for now they're sea ice.

And arctic sea ice, of course,

has been melting due to man-made global warming.

So, we'll start over here.

If you have meat in your diet for a year in the U.S.,

you melt this much sea ice.

Alex: Oh, my God.

And that is actually the square footage.

- Exactly, yes. - Wow.

If you drive a car for a year in the U.S.,

Alex, you melt this much sea ice.

- Should I roll this? - Yeah.

Okay.

Oh, this is shameful.

Whoa.

What kind of car do you drive?

I drive a Nissan Silvia.

Oh, that's devastating.

You probably drive less than the average American.

Yeah, but it only gets, like, 16 miles to the gallon.

Not great.

And this is the ice that melts

from the average American's air travel in a year.

And that doesn't seem like a lot

because it's the equivalent of just one round trip

between New York and California.

But that generates the same emissions

as around four months of driving.

But, of course, the four of us,

we are not the average flyer.

Oh, no.

So, we're gonna go over there now.

- Oof. - Ours are gonna be huge.

- Uh-oh. - ( chuckles )

- I think I see my pile. - Yeah, same.

Okay, we're gonna start with this one.

You guys want to help me fold it out?

- Yeah. - Let's just start with half.

This way, and then it goes...

- Christophe: Oh, my God. - Alex: Ooh, wow.

I was gonna say it's like the car, but this is--

- This is yours? - Joss: This is mine.

- What? - Whoa.

Oh, no.

But this isn't even, like-- this is just you flying.

- This isn't even you as an individual with-- - In a year. Right.

Okay, now let's go over and check this one out.

- It's Alex. - Alex!

- Yeah, that's me. - Joss: You did pretty good.

Still more than the average American, though, right?

Still more than the average American.

Yeah, I'm like two Americans.

Still not good.

- Okay, big boy. - Who could this be?

Oh, no!

Oh, this is so embarrassing.

- Cleo: Whee! - This just keeps going.

Well, I feel terrible.

- Okay, let's do the last one. - ( Cleo groans )

I like how the number of times it has to be folded...

- Tells you a lot. Right. - ...kind of gives us an idea.

Cleo: Oh, my God.

Alex: It's like a small whale.

Christophe: Oh, no.

Cleo: It's like a big whale.

- Well, it's a lot of ice. - It's a lot of ice.

Joss: But it's not really about any individual.

I mean...

Like, you flew all over the place for work this year.

- It is mostly work. - Yeah.

- But still. - Maybe something for Vox to think about.

Christophe: Yeah.

( music playing )

Oh, it's so heavy.

Yeah.

Oh, my bad. ( laughs )

Joss: So, altogether, we flew

on 84 airplanes in the past year.

- Alex: 84 separate airplanes? - Joss: 84 separate airplanes.

Do you guys know how many flights there are

in a year around the world?

- Oh, hundreds of thousands? - In a year?

There are 35 million flights around the world in a year.

Christophe: 35 million.

Which is almost 100,000 every single day.

Huh.

- So, let's go sit down over here. - Alex: Yeah.

Joss: And what's interesting about that

is that all those flights are being taken

by a minority of the world's population.

- Mm-hmm. - So, by some estimates,

only 20% of humans have ever flown on an airplane.

- Cleo: Whoa. - Wow.

And even within the U.S., only about half of Americans

fly in a given year.

It's about 12% of adults in the U.S.

that are taking 70% of the flights. People like us.

And that's where it gets into the big ethical issue with climate change,

is that the people who have used the most fossil fuels

generally have more resources

to deal with the impacts of climate change.

So we're talking about stronger storms,

more floods, more droughts, deadly heat waves.

It's really the world's poor

who are the most vulnerable,

and in most cases, we're talking about people

who have never seen the inside of an airplane.

And some people are taking this so seriously

that they're completely changing the way they travel.

Is this 16-year-old young lady

now the leader of the climate change movement?

Anchor #2: She is definitely the face.

Anchor: And she's given a big push

to the flight shaming movement.

That is you're called out, you're shamed if you fly.

So, Joss asked me to go see Greta Thunberg arrive in New York City.

She's been sailing across the Atlantic

for the last two weeks, I think.

Her trip is a part of a larger movement called "flygskam,"

which is Swedish for "flying shame."

And, honestly, it's kind of working.

In Sweden and other parts of Europe,

people are starting to brag on social media

about traveling by train instead of by plane.

And the data shows that in Swedish airports,

passenger counts are down as well.

Cleo: You look great.

That diagonal sail, that's her.

( crowd chanting ) Greta! Greta! Greta!

And she's about to set foot on land for the first time.

( crowd cheering )

Greta Thunberg: Well, all of this is very overwhelming,

and the ground is still shaking for me.

- ( Skype rings ) - Hey.

- Hey, Joss. - So, Umair.

You've been following the flight shame movement

as it's been developing this year.

What are some of the critiques

of the shaming approach?

Well, in order to solve climate change,

a massive global problem,

you really need to be taking big bites of the apple.

And the critique here is that focusing