How refrigeration took over the world

Summary

Planet Money: How Refrigeration Took Over the World

NPR, September 26, 2025
Hosts: Nick Fountain & Alexi Horowitz Ghazi
Guest Expert: Nicola Twilley (journalist, author of Frostbite, host of Gastropod)

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Episode Overview

This episode explores the remarkable, world-altering story of refrigeration and its profound economic, social, and historical impacts. Hosts Nick and Alexi, alongside refrigeration expert Nicola Twilley, guide listeners through the cold chain’s technical innovations, ripple effects on society, unexpected global shifts, and the trade-offs that come with living in a permanently cooled world. From the birth of refrigerated warehouses to the invention of the cheeseburger, and even Irish independence, Planet Money traces how “cold” changed everything.

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Key Discussion Points & Insights

Inside the Cathedral of Cold (00:30–03:48)

• Warehouse Visit:

  • Nick tours an enormous refrigerated warehouse with Nicola Twilley, highlighting its role as a silent marvel of the modern economy:

    “It’s an enormous refrigerated warehouse filled with enough food to feed an entire city.” — Nick Fountain (00:48)

  • Discussion of “suspended animation” for produce, with fruits and veggies carefully stored to slow their “breathing” and extend freshness.
  • Each storage room is a carefully controlled “microclimate” designed for specific crops.

• Produce Lives On:

  • “Just because a fruit or a vegetable has been harvested doesn’t mean it’s dead. Exactly. It’s just in a sort of suspended animation.” — Alexi Horowitz Ghazi (01:38)
  • “It is still breathing and it has a certain number of breaths it can take before it dies... The whole trick with produce is making it breathe more slowly, which you do by refrigerating it.” — Nicola Twilley (01:58)

• Tomato Storage:

  • Not all produce likes the cold; tomatoes lose flavor if stored too cold.

    “If they’re stored too cold for too long, they actually lose their ability to generate flavor.” — Nick Fountain (03:19)

  • Advice: “Do not refrigerate your tomatoes.” — Alexi Horowitz Ghazi (03:24)

Refrigeration's World-Altering Impacts (03:48–04:18)

• Nicola Twilley notes refrigeration changed everything from gut microbes to fashion (the hoodie!), Irish independence, and global politics.
  • “The cheeseburger did not exist until refrigeration made it possible.” — Nicola Twilley (04:10)

The Meat Revolution & Birth of the Cold Chain (05:54–13:27)

• Pre-Refrigeration Era:

  • Fresh meat had only a 2–3 day shelf life, making urban meat supply unsanitary and inefficient.

• Gustavus Swift — The Relentless Cheapskate:

  • Swift's drive: eliminate waste, centralize meat processing, and monetize byproducts.

    “He is famous for not wanting to let a single thing go to waste.” — Guest Expert (08:11)

  • Created the “disassembly line,” precursor to Henry Ford’s assembly line.
  • Moved meatpacking to Chicago, the hub of beef, and sought ways to distribute fresh meat to the East Coast.

• Technological Breakthroughs:

  • Experimented endlessly to develop effective refrigerated rail cars—but many early failures due to ice placement, circulation, and spoilage.

    “It was just a disaster. And so everyone had sort of decided, this isn’t going to work. But not Gustavus.” — Guest Expert (10:16)

  • The final design: insulated cars with ice at the top, cold air circulating down, and ice replenished along the route.

• Economic Transformation:

  • By centralizing slaughter and using refrigeration, Swift could undercut prices; meat became affordable for city laborers.
  • “He was able to sell it so cheaply, because… he’s not paying to ship the half that you can’t sell, and he’s monetizing all the byproducts.” — Guest Expert (11:13)
  • Introduction of “the cold chain”: food kept in a continuous climate-controlled sequence from farm to store.

• Ripple Effects:

  • Enabled national and global food distribution; grocery stores now offer green beans from California or butter from New Zealand, all thanks to the cold chain.

Trusting Cold: The Polly Pennington Story (13:07–16:29)

• Reluctance to Trust Refrigerated Food:

  • Americans were skeptical of food that wasn’t locally or recently slaughtered; initial cold-chain incidents led to hesitancy and safety concerns.

• Polly (M.E.) Pennington — Food Safety Icon:

  • Chemist and federal inspector who became legendary for standardizing and testing safe storage and transport.

    “She is the person who basically made Americans trust refrigeration. That is her legacy.” — Guest Expert (14:32)

  • Rode trains nationwide, sampling and inspecting foods in transit. Developed standards still seen today (e.g., egg grading).

• Shifting Public Perception:

  • Thanks to Polly’s advocacy and scientific rigor, Americans shifted from fearing refrigerated food to believing “anything that wasn’t refrigerated couldn’t possibly be fresh. Literal 180.” — Guest Expert (16:10)

How Cold Changed Time, Space, and Society (16:33–19:44)

• “Cold Chain as Time Machine”:

  • Apples can now be stored for 10 months; “we can live in this sort of endless summer where everything is always in season.” — Alexi Horowitz Ghazi (16:52)

• Shifting Geography:

  • Farms no longer need to be close to cities—most U.S. lettuce now comes from just two regions.

• Women and Work:

  • Home refrigeration and frozen foods reduced the labor of daily shopping/canning.
  • “As home refrigeration, frozen food expands in the 20th century... women in the workforce. So also divorce rates.” — Guest Expert (18:00)

• Historical Reverberations:

  • World War II: Refrigerated blood saved soldiers.
  • Central America: Refrigerated bananas reshaped economies and politics.
  • Irish Independence: Cheap, imported meat weakened Ireland’s economic role, nudging toward independence.

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Downsides of a Chilled World (20:37–23:37)

• Taste Decline:

  • Fruits like cherries and tomatoes lose flavor over time and cold storage.

    “In places that have not adapted to refrigeration, they taste American food and they say it tastes dead.” — Guest Expert (20:47)

• Food Waste:

  • Refrigeration moved waste downstream; 30–40% of all food now wasted on the consumer end due to easy availability.

    “The food waste on the consumer end… that has gone up to 30 or 40% of all foods.” — Guest Expert (21:51)

• Energy and Environmental Cost:

  • Refrigeration contributes roughly 2% of global emissions—a figure equal to aviation.
  • Just slightly raising freezer temps worldwide could cut emissions (by the equivalent of 4 million cars).

    “Just that tiny move… is equivalent of getting like 4 million cars off the road.” — Guest Expert (23:23)

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Notable Quotes & Memorable Moments

• “Refrigeration is this kind of time machine. An apple can be picked and stored for 10 months. The cold chain means that we can live in this sort of endless summer where everything is always in season.” — Alexi Horowitz Ghazi (16:52)
• “The cheeseburger did not exist until refrigeration made it possible. So it is transformative on every level.” — Nicola Twilley (04:10)
• “She [Polly Pennington] is the person who basically made Americans trust refrigeration. That is her legacy.” — Guest Expert (14:32)
• “So just 3 degrees will have a huge impact.” — Nick Fountain (23:32)
• “Before working on this story, I gotta admit, I kinda took refrigeration for granted… But after reading Nikki’s book, I started to think of the cold chain as like this force that can bend time and space and change the economy, even change history.” — Nick Fountain (23:51)

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Key Segment Timestamps

| Timestamp | Segment/Topic | |-----------|------------------------------------------------| | 00:30 | Inside the cold warehouse | | 01:58 | Fruits & veggies in “suspended animation” | | 03:24 | Why you shouldn’t refrigerate tomatoes | | 04:10 | Everything changed: cheeseburgers, hoodies | | 06:06 | Pre-refrigeration problems | | 07:21 | The innovations and thrift of Gustavus Swift | | 11:03 | Birth of effective refrigerated rail cars | | 12:48 | The birth of the “cold chain” | | 14:19 | Polly Pennington rides the rails | | 16:52 | Refrigeration as a time machine | | 18:00 | Impact on women’s roles, convenience | | 19:14 | Cold chain & Irish independence | | 20:47 | Taste and food “deadness” post-refrigeration | | 21:51 | Food waste shifts to the consumer | | 22:41 | Refrigeration’s global emissions | | 23:23 | Small changes = big environmental impact | | 23:51 | Hosts reflect on refrigeration’s hidden power |

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Tone & Style

• Lively, curious, and often humorous (“I started to think of the cold chain as like this force that can bend time and space”).
• Engaging real-world analogies and unexpected historical rabbit holes.
• Genuine wonder and respect for overlooked technology—and concern about its externalities.

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For Further Exploration

• Frostbite by Nicola Twilley for a deep dive into refrigeration’s history.
• See the “cold chain” in action, from farm to fridge.
• Reflect on how everyday tech—often invisible—can fundamentally (and quietly) reshape the world.

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End of episode summary.
If you’re now eyeing your own fridge and produce drawer with newfound wonder or guilt, you’re not alone.

Transcript

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[Nick Fountain]

The other day I donned a hair net and a very unfortunate beard net. Hey, here we are. And got to visit a place I'd wanted to for a very long time.

[Nicola Twilley]

Smell of produce pallets racking the whole thing.

[Nick Fountain]

This place is low key, one of the wonders of the modern world. It's an enormous refrigerated warehouse filled with enough food to feed an entire city. My guide to this miracle is Nicola Twilley.

[Guest Expert / Historian]

We're heading in.

[Nicola Twilley]

It's noisy food.

[Nick Fountain]

Journalist, host of the podcast Gastropod and author of a recent book about refrigeration called Frostbite.

[Alexi Horowitz Ghazi]

Nikki has become obsessed with places like this. She's spent the last decade visiting them and even worked in some of them.

[Nicola Twilley]

It's a cool. It's a. It's a cool world.

[Nick Fountain]

The warehouse we're in today is enormous. The size of two football fields.

[Nicola Twilley]

Don't get run over. Careful, careful.

[Nick Fountain]

Fruits and veggies are coming in from all over the world and going out to supermarkets and restaurants across Southern California and beyond.

[Alexi Horowitz Ghazi]

There are all these storage rooms with very particular microclimates, each the perfect temporary home for a bell pepper or a jackfruit or a horseradish. Because, as Nikki tells us, just because a fruit or a vegetable has been harvested doesn't mean it's dead. Exactly. It's just in a sort of suspended animation.

[Nicola Twilley]

It's like us. It's still breathing. It is breathing and it has a certain number of breaths it can take before it dies.

[Nick Fountain]

I'm sorry. A head of lettuce has been decapitated. How could it possibly be alive?

[Nicola Twilley]

I mean, it is dying, but so are we. I hate to break it to you, and like us, it has a certain number of breaths it's going to take before it dies. And the whole trick with produce is making it breathe more slowly, which you.

[Alexi Horowitz Ghazi]

Do by refrigerating it. Each fruit and vegetable has a perfect temperature to optimize that breathing.

[Nick Fountain]

Nikki leads me through one of those vinyl strip doors with all the pieces of plastic hanging down and. And into a slightly louder room. This one is for things like eggplants and tomatoes.

[Nicola Twilley]

Okay, so did you notice the temperature change?

[Nick Fountain]

Yeah. It's much warmer in here.

[Nicola Twilley]

It is much warmer.

[Nick Fountain]

There are Pallets full of Roma tomatoes, but also beefsteak tomatoes, heirloom tomatoes, grape tomatoes, cherry tomatoes, probably some other tomato varieties I've never heard of, all kept at a balmy 45 degrees.

[Nicola Twilley]

Tomatoes, which I'm going to say tomatoes. I'm sorry.

[Guest Expert / Historian]

I grew up in England, and I.

[Nicola Twilley]

Haven'T made the leap for that word.

[Nick Fountain]

Deal with it, people.

[Nicola Twilley]

Exactly. Listen, try it yourself. You might prefer it. Tomatoes are really, really sensitive.

[Nick Fountain]

If they're stored too cold for too long, they actually lose their ability to generate flavor.

[Alexi Horowitz Ghazi]

Yeah. So news you can use. Do not refrigerate your tomatoes. That's why supermarket tomatoes often taste so bad.

[Nick Fountain]

Being there in that warehouse, it was like being in a cathedral devoted to everything humanity has learned in the last 150 years about how to refrigerate our food. And being there with Nikki, well, that was like getting a tour from the Pope of refrigeration.

[Nicola Twilley]

It literally changed everything from the contents of the microbes that live in our gut to the invention of the hoodie.

[Guest Expert / Historian]

You're wearing a hoodie right now.

[Nicola Twilley]

That wouldn't exist without refrigerated warehouses. To Irish independence. You know the politics of Central America. The cheeseburger did not exist until refrigeration made it possible. So it is transformative on every level.

[Alexi Horowitz Ghazi]

Hello, and welcome to Planet Money. I'm Alexi Horowitz Ghazi.

[Nick Fountain]

And I'm Nick Fountain. Today, an entire show about refrigeration. How it changed the course of history and remade time and space.

[Alexi Horowitz Ghazi]

We'll meet the chemist who crisscrossed the country by train in her quest for food safety. And the notorious cheapskate who brought meat to the masses.

[Nick Fountain]

I'm gonna make a suggestion. We should do the rest of this interview in a warm place.

[Guest Expert / Historian]

I'm so on board.

[Nicola Twilley]

I love the cold, but not that much.

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[Nick Fountain]

To truly appreciate the miracle of widespread refrigeration, let us go back to the time before that miracle, say, the mid-1800s.

[Alexi Horowitz Ghazi]

It was a simpler time, but also a smellier time, in part because of food. Unrefrigerated food rots pretty quickly. And this is especially true for meat.

[Nick Fountain]

Yeah, without refrigeration, if you want fresh meat, you have two, maybe three days between when you slaughter an animal and when you have to eat it. Otherwise, bad things will happen.

[Alexi Horowitz Ghazi]

And one interesting thing Nikki's book points out is that this was just really economically inefficient. In the mid-1800s, cows were raised in one place and then brought to the big urban centers. They would either have to walk or come in on trains.

[Guest Expert / Historian]

Cattle would commute hundreds of miles to get slaughtered in the city. And you can imagine they're losing a bunch of weight while they're doing that.

[Nick Fountain]

So kind of wasteful, but also pretty unsanitary.

[Guest Expert / Historian]

Then they have to be slaughtered in the city center, which you know is relatively close to where all the people are living. And so you get these horrific scenes of sort of blood and gore to.

[Alexi Horowitz Ghazi]

Cut down on the cattle commutes and clean up all that blood and gore. The world needed a special kind of hero, one who would revolutionize how America.

[Nick Fountain]

Got its food, enter into this world. A notorious cheapskate. Who is that?

[Guest Expert / Historian]

Gustavus Swift. Yeah, he's a. He's a New Englander with a New Englander sense of thrift.

[Alexi Horowitz Ghazi]

Cheapskate. Gustavus Swift was born in 1839. His brother, Noble, was a butcher. And young Stav, as he was known, followed in his brother's footsteps at the age of 14.

[Nick Fountain]

Yeah. Gustavus would travel from Cape Cod, where he lived. He would buy a cow outside of Boston, slaughter and quarter it there, and then bring the meat back to the Cape to sell it door to door. But he couldn't help but notice that he always had to leave, like, half of the cow behind.

[Guest Expert / Historian]

Only 50% of it is edible. The rest is essentially trash.

[Nick Fountain]

What are we talking about? The bones, the sinews, that sort of stuff.

[Guest Expert / Historian]

Intestines, blood. There's a lot of hide there. There's a lot of hoof there.

[Nick Fountain]

And this drove Gustavus Swift up the wall.

[Guest Expert / Historian]

He is famous for not wanting to let a single thing go to waste.

[Nick Fountain]

And there were uses for these byproducts. These were the raw materials for things like soap or fertilizer or glue. But you had to have a certain scale to make it worthwhile.

[Alexi Horowitz Ghazi]

Gustavus figured if he could just centralize meat production and slaughter all the animals in one place, he could gather up all the bones and sinews and hooves anyone would ever want and sell them.

[Nick Fountain]

So he moves to Chicago, which is sort of the hub for all the beef coming off the Great Plains, and gets to work setting up giant butcher shops, or as they came to be known, meat packing plants, where cow carcasses would be yanked around on hooks and each worker would do a little discreet part of the slaughtering and butchering process. These were called disassembly lines, which, fun fact, inspired Henry Ford's assembly lines.

[Alexi Horowitz Ghazi]

Also not so fun fact. Meatpacking plants were horrendous for animals and for the people who worked there. And so they also inspired Upton Sinclair's book the Jungle.

[Nick Fountain]

Yeah, pretty nasty stuff. But at least now they could use all the cow hooray. Still, it wasn't like there was a market in Chicago itself for all that meat. To get this to really work, Gustavus needed to figure out how to get his very perishable product, this meat, to. To cities on the East Coast.

[Guest Expert / Historian]

And at the time, people had started to experiment with using ice on railway cars to keep meat cold, and they could not make it work.

[Nick Fountain]

Oh, what was the problem?

[Guest Expert / Historian]

You might think ice just would make it cold, and no big deal. That works in your yeti. It does not work in a rail car full of slaughtered meat. So if any of the meat touches the ice, it gets a frozen burn and wet. If the ice melts too fast, there's too much water. Meat doesn't like that. Slimy bacteria grows. If the air doesn't circulate well, you'll get hot spots and cold spots, and the hot meat will rot, and the cold meat might freeze. I mean, if the train pauses, you could lose the entire load. I mean, it was just a disaster. And so everyone had sort of decided, this isn't going to work.

[Alexi Horowitz Ghazi]

But not Gustavus.

[Guest Expert / Historian]

Gustavus set about this with gusto, I guess, and tried everything. He tried putting the ice at the bottom, he tried putting the ice at the top, he tried putting ice at the sides. He had one brilliant idea where there was a fan attached to the axle of the rail car, which made sure the air circulation was there. Great idea. Until the train stopped, and then the wheel wasn't turning and the fan wasn't blowing.

[Nick Fountain]

But finally, Gustavus and an engineer succeeded in designing a train car that would keep meat cold. It was well insulated. You could add ice from the top along the journey, and it would automatically push cold air down from that ice.

[Alexi Horowitz Ghazi]

In the end, Gustavus plan to centralize meat processing and make it more economically efficient totally worked. He was able to significantly undercut what his competitors were charging for meat.

[Guest Expert / Historian]

He was able to sell it so cheaply, because think about it, he's not paying to ship the half that you can't sell, and he's monetizing all the byproducts.

[Nick Fountain]

Wow.

[Guest Expert / Historian]

So he was able to just slash the price. And there were enough meat starved, poor working people in the cities who had not been able to afford meat before, who suddenly could afford meat, that his business took off.

[Nick Fountain]

Now, there was one last innovation that Gustavus popularized that we have not mentioned yet, one that was maybe even more important than those refrigerated train cars. He figured out how to cool down his packing plants full of meat almost immediately post slaughter. And that meant his beef was refrigerated from the time that it was butchered to the time that it arrived in whatever city he was going to.

[Alexi Horowitz Ghazi]

This technique ended up being applied to all kinds of foods. Nikki says it's how we got the world we live in today. I mean, think about all the things you can buy at the grocery. Green beans from California, strawberries from Mexico, butter from New Zealand.

[Guest Expert / Historian]

And you have to imagine a series of refrigerated links extending and connecting your fridge all the way back to the farm. So when something like a green bean is harvested immediately, it is pre cooled. Then you store in a cold storage unit. You ship in a refrigerated truck. It goes to a refrigerated warehouse like we saw today. They ship it in a refrigerated truck. The grocery store puts it on a refrigerated shelf and you purchase it.

[Nick Fountain]

The fancy term for this end to end refrigeration, the cold chain.

[Guest Expert / Historian]

So the cold chain is all of those cold spaces that mean that your food should be able to move from the farm essentially to the point of purchase without ever being outside of the cold.

[Alexi Horowitz Ghazi]

But to understand how we got to this cold chain connected world we live in now, we need to talk about one more big chapter in the history of refrigeration. Because sure, Gustavus Swift had come up with new ways of keeping food cold all along the supply chain, but that did not mean that Americans were immediately ready to trust those foods.

[Guest Expert / Historian]

Oh, yeah? Well, just imagine, for all of human history, you have known what fresh means. And fresh means it was picked or it was slaughtered in the past couple of days within like, I don't know, dozen miles nearby and recently.

[Alexi Horowitz Ghazi]

And now people like Gustavus were trying to sell you meat from halfway across the country that had been slaughtered who knows when. Sounded like a recipe for food poisoning.

[Nick Fountain]

And it's not like this fear was unfounded. At the beginning, refrigeration was a pretty imprecise art.

[Guest Expert / Historian]

There's no one overseeing this. Warehousemen are like, well, seems like a good temperature for eggs. We'll store them at this temperature no one studied. Is this the right temperature for eggs?

[Alexi Horowitz Ghazi]

And what about for milk or chicken or seafood?

[Nick Fountain]

No one had done the research until who walked onto the scene.

[Guest Expert / Historian]

Oh, one of my favorite people in the book, M.E. pennington, went by Polly, except for when she was going as Dr. M. Pennington, so that the men of the era would not realize that she was a woman. And she is the person who basically made Americans trust refrigeration. That is her legacy.

[Nick Fountain]

Polly Pennington was a chemist. Around the turn of the century, she started working for the Philadelphia Bureau of Health, cleaning up the city's milk supply. From there, she moved on to the federal government. Her job, her figuring out how to safely store and transport all of these different kinds of foods, which was way more exciting than it sounds.

[Guest Expert / Historian]

She traveled the country. She had a little train car that she would attach to, you know, Gustavus's rail cars. And she would sample a chicken to make sure it was at the right temperature. She is amazing.

[Nick Fountain]

She was riding the rails for food safety.

[Guest Expert / Historian]

She was riding the rails for food safety. There's amazing pictures of her in her sensible, divided skirt reaching into these ice filled rail cars and, and she became an absolute icon in the food industry.

[Nick Fountain]

Name a person in the food industry more iconic. Alexi. Do it.

[Alexi Horowitz Ghazi]

Uh, Guy Fieri. Sorry, sorry. The truth hurts. But leaving that particular icon aside, if you've ever checked the grade on the side of your egg carton, you have Polly Pennington to thank.

[Nick Fountain]

If you've ever eaten American chicken or shrimp or fish and not gotten sick, tip your hat to Paulie.

[Alexi Horowitz Ghazi]

But if you've ever thrown donkey sauce on it, that's going to have to be credited to all American food icon Guy Fieri. But okay, Polly Pennington's legacy is maybe a bit more substantial. She did change the way people in the industry stored and transported their food. And she did launch a kind of public relations campaign about all this stuff.

[Guest Expert / Historian]

And at the end of her life, she had managed to, to Make Americans go from thinking that refrigerated food was a dangerous scam to believing that anything that wasn't refrigerated couldn't possibly be fresh. Literal 180. She made Americans believe in refrigeration.

[Alexi Horowitz Ghazi]

Polly Pennington, fully pasteurized, Grade A legend.

[Nick Fountain]

Pour some out for her. Some 2%, because look at all the things that her work and the work of Gustavus before her brought about. Yeah.

[Alexi Horowitz Ghazi]

Let's just take a moment, Nick, to kind of sit and revel in all of the incredible ripple effects from the mass adoption of refrigeration in the cold chain.

[Nick Fountain]

Here, let us.

[Alexi Horowitz Ghazi]

Yes. Like how refrigeration is this kind of time machine. An apple can be picked and stored for 10 months. The cold chain means that we can live in this sort of endless summer where everything is always in season.

[Nick Fountain]

And it didn't just shift our sense of time. Nikki says it also shifted our sense of space. It totally transformed the geography of farming. Used to be, if you wanted salad greens, you bought them from whatever farmer happened to live near you. But these days, a large majority of the lettuce our country eats comes from the two places with the climate best suited to growing lettuce. The Salinas Valley in California and Yuma, Arizona. That concentration was. Wouldn't be possible without the cold chain.

[Guest Expert / Historian]

So it allows the advantage of climate and soil to overtake the advantage of proximity that previously someone close to a city who was growing lettuce would have had.

[Nick Fountain]

And when you start to change how people put food on the table, you start to change all sorts of things. Nikki says. Think about how refrigeration changed the role of women in society.

[Guest Expert / Historian]

So pre refrigerator, you know, women were. Had a huge amount of labor canning fruits and vegetables in the summer to last through the winter, and then shopping every day if they lived in the city, trying to buy fresh food for that evening's meals. There's no such thing as leftover. There's no such thing as frozen convenience food. And as home refrigeration, frozen food expands in the 20th century, well, guess what? Rises in lockstep. Women in the workforce. So also divorce rates.

[Nick Fountain]

There you go.

[Nicola Twilley]

I know.

[Guest Expert / Historian]

No comment.

[Alexi Horowitz Ghazi]

And it's not just the slow erosion of the patriarchy either. Nikki says you can see the cold chain's influence on so many historical events, like how refrigerated shipments of blood for transfusions helped American soldiers in World War II.

[Nick Fountain]

Or how the ability to transport fruit from Central America changed the economies of some of the countries there. And next thing you know, American corporations were doing everything they could to turn them into banana republics.

[Guest Expert / Historian]

One of the most astonishing stories I came across while writing the book was an economist who was like, would Ireland have become independent without refrigeration?

[Alexi Horowitz Ghazi]

To be clear, even the economist here, he's not saying definitively that the cold chain caused Irish independence. But here's how his thinking worked. A lot of beef for the English was raised in Ireland, but. But once frozen beef could be imported from places like South America, then the price of Irish beef went way down. And that made life really hard in Ireland, fueled discontent among the Irish tenant farmers, and made British landlords more willing to sell their land.

[Guest Expert / Historian]

Before you know it, you have Irish independence.

[Alexi Horowitz Ghazi]

So many surprising ripple effects. Who knew?

[Nick Fountain]

Quite, quite the theory.

[Alexi Horowitz Ghazi]

I might buy it. I'll take it. Coming up in a hot minute, the downsides of our cold, cold world. Starting with one of the most fundamental things about food itself.

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[Nick Fountain]

Okay, obviously refrigeration is not perfect, so real quick, let's run through a few of the downsides. According to Nikki, starting with food actually.

[Guest Expert / Historian]

Doesn'T taste the same anymore. In places that have not adapted to refrigeration. They taste American food and they say it tastes dead.

[Nick Fountain]

And are they just tasting the tomatoes?

[Guest Expert / Historian]

No, not just. Not just.

[Alexi Horowitz Ghazi]

Yeah, it's cool to be able to eat cherries that were picked a month ago in Chile, but they're not going to taste as good as fresh ones. As soon as a cherry is picked, it starts to lose its acidity and its flavor.

[Nick Fountain]

But still, you can get cherries pretty much all year round. All kinds of food.

[Guest Expert / Historian]

We have more of it and it is cheaper, but it is not as delicious.

[Nick Fountain]

Okay, so that's taste problem number two. Has to do with waste. And this is a little surprising, right? The whole point of refrigeration is to keep food from spoiling.

[Guest Expert / Historian]

Prior to refrigeration, between 30 and 40% of food would go bad before it ever even reached the market. It would have to be thrown away. So refrigeration has minimized that, but that.

[Alexi Horowitz Ghazi]

Waste hasn't gone away, it's just moved further down the timeline.

[Guest Expert / Historian]

The food waste on the consumer end, where we've purchased it from the grocery store or it's gone to restaurants, that has gone up to 30 or 40% of all foods.

[Nick Fountain]

Refrigeration, along with a bunch of other things, has brought the cost of food way down. Which makes it easy to be a little careless with our food purchases. I mean, right now in my crisper drawer there are like three bags of aspirationally bought arugula. One of those is going to get tossed.

[Alexi Horowitz Ghazi]

I shudder to even look in my crisper drawer.

[Nick Fountain]

And last but certainly not least, there's the problem of how much energy all this refrigeration uses.

[Guest Expert / Historian]

So yeah, it's a sad irony that as we build more and more artificially cold space, our naturally cold space disappears. Thanks to climate change, refrigeration accounts for.

[Nick Fountain]

2% of the world's emissions. That's on par with aviation. And that number is set to grow rapidly as much of the developing world builds out its own cold chain.

[Alexi Horowitz Ghazi]

Some teeny tiny good news here, there is some low hanging fruit. When it comes to the energy consumption of the cold chain. Nikki says there are some folks in the industry who are right now trying to get everyone on board with slightly turning up the thermostats in their freezers.

[Guest Expert / Historian]

From minus 18 to minus 15 degrees. Those are Celsius.

[Nick Fountain]

It's okay. Very, very cold. Way below freezing to a little bit less below freezing.

[Guest Expert / Historian]

Exactly.

[Nick Fountain]

Turns out minus 18 degrees Celsius, that might be colder than it needs to be.

[Guest Expert / Historian]

And it's been estimated that just that tiny move, moving frozen food around at minus 15, which is perfectly safe, is equivalent of getting like 4 million cars off the road.

[Nick Fountain]

Wow. So just 3 degrees will have a huge impact.

[Guest Expert / Historian]

Huge impact.

[Alexi Horowitz Ghazi]

So just like every other major new technology, the cold chain has come with all sorts of trade offs and unintended consequences. But refrigeration has made our food system cheaper and safer and more abundant than ever.

[Nick Fountain]

Yeah. Before working on this story, I gotta admit, I kinda took refrigeration for granted. We've grown up with it just quietly humming along in the background. But after reading Nikki's book, I started to think of the cold chain as like this force that can bend time and space and change the economy, even change history.

[Alexi Horowitz Ghazi]

Yeah. Now every time I walk by my fridge these days, I can't help but just, you know, crack a smile, give it a little pat on its sweet stainless steel little belly and say thank you you know, that'll do, Fridge. That'll do.

[Nick Fountain]

Is there some undersung technology or person who didn't get their due in the economic history textbooks or podcasts? Let us know. Send us an [e-mail] or you can find us on a lot of different social medias.

[Alexi Horowitz Ghazi]

Today's episode of Planet Money was produced by James Sneed. It was edited by Keith Romer, fact checked by Cierra Juarez and engineered by Valentina Rodriguez Sanchez. Alex Goldmark is our executive producer. I'm Alexi Horowitz Ghazi.

[Nick Fountain]

I'm Nick Fountain. This is npr. Thank you for listening. And give your refrigerator a pat on its belly.

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