Instant Genius - Feeding the world’s growing population

Episode Date: December 2, 2024

The Earth’s population currently stands at more than 8 billion and shows no signs of slowing down any time soon. There’s little doubt that these staggering numbers are placing a huge strain on global food supplies, so what can be done for the human race to thrive and survive long into the future? In this episode, we catch up with multidisciplinary researcher and author Prof Vaclav Smil to talk about his latest book – How to Feed the World. He tells us how evolution has determined the staple foods we now rely on for nourishment, how this influences our chances of continued survival and why technology is yet to find a viable solution to the urgent issue of feeding the world. Learn more about your ad choices. Visit podcastchoices.com/adchoices

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delivering digital precision with analogue warmth. So you can experience exceptional sound at home. Music just as the artist intended. Visit name audio.com. to learn more. Hello and welcome to Instant Genius, a bite-sized masterclass in podcast form. Every Monday and Friday, you'll hear world-leading scientists and experts talking about the most fascinating ideas in science and technology today.

I'm Jason Goodyear, commissioning editor, the BBC Science Focus. The Earth's population currently stands at more than 8 billion and shows no signs of slowing down anytime soon. There's little doubt that these staggering numbers are placing a huge strain on global food supplies. So what can be done if the human race is to thrive and survive long into the future? In this episode, we catch up with multidisciplinary researcher and author Professor Vaclav Schmill to talk about his latest book, How to Feed the World. He tells us how evolution is determined the staple foods we now rely on for nourishment, how this influences our chances

of continued survival, and why technology is yet to find a viable solution to the urgent issue of feeding the world. Welcome to the podcast. Thanks very much for joining us. Okay, thank you. So today we're talking about your book, How to Feed the World. In the intro, you make quite a strong statement about what you're trying to explain. So could you unpack that for us, please? Well, what I always think when I write my books, which usually is about complex matters,

you know, energy, environment, history of technical innovation, I always try to introduce a great deal of uncertainty and complexity, because that to me is everything is about that. I just absolutely that there's some kind of simple statement. We are doomed, right? Or, you know, in recent months especially, AI will solve everything. That makes me extremely allergic. I want to walk away from the room, right?

AI will solve everything. So that kind of thing I always try to avoid. So in this book, I try to read just very few simple things to remind people of the basics. The basics is that, you know, sun is to shine and photosynthesis has to work, but it's an extremely inefficient reaction, and there is very little

we can do about it. We can fiddle on the margins, but still, you know, most of that sun will never be turned into edible matter, no matter, plant or human, right? And we have done tremendous amount of work, how to improve it, not the efficiency of photoscence

itself, but how to enhance the conditions, fertilizing, irrigating, pesticides, but still, know, we are fundamentally limited, and there is only so much we can do. Yet, you know, we have this rising demand. I mean, the population will not go to 15 billion, but, you know, it may go to whatever, nine, nine and a half billion.

So there is still more food needed for more people, and quite a few people are still undernourish, not necessarily in certain kind of, they will die tomorrow terms, but, you know, the micro-nutrition, protein undernutrition, so definitely we will need more food. there is this tension between these natural limits and between how much we can do to improve that production. We'll get into that in a little while. But in the book, you kick off with the advent of humans changing from hunter-gatherers to farmers.

So why did you start so far back? Well, because, you know, as the famous American geneticist and evolutionary biologists, Theodore Zerzziuz Dobzjanski said, you know, in biology, nothing makes sense. Then you overlook the evolution. And this is where it all started. We still are what we were, you know. I mean, we discovered a long time ago, just by trial and error, that if you want to increase the numbers,

and the story of human civilization is increasing the population numbers, like it or not, but this is one overriding variable, because society is a kind of low-tech, high-tech, mid-tech, but still over a long period of time, they kept increasing their numbers. So if you increase your numbers, you cannot keep being a, gather, hunter or scavenger. You've got to settle down and you've got to farm. And so this is this evolutionary threat going way, way back really,

and we are still following that. Want to have large numbers? Want to have large numbers? Now, our farming now is very, very different from it, to what it used to be. But still, it's the fundamental existential mode. We could never have a society of 1 billion, forget about 8 billion people,

without having intensive farming. That's given, right? So any idea, and from that flows the other thing in the book, that any idea, especially with eight grand people, we could return to less intensive ways of farming, like fully organic farming, right? It just simply wouldn't work because numbers are simply too big. So the numbers, the scale, determines everything. So I find this really interesting, the proliferation of different food crops around the world. So for example, I live in the UK and we eat a lot of potatoes, but potatoes are. native to the UK. We also love a curry, but chilies aren't even native to India. The same goes

for tomatoes not being native to Italy. So I find that mind-boggling. How has that happened? Well, what's mind-boggling actually in a way that how little we use? Because if you look at the universe of plants, there are so many plant species, and 99% of them we will never eat. Because, of course, you know, the streets, there is a bark and there are needles, so these things are basically unpalatable, undigestable, whatever. But there is lots of biomass out there, which is digestible, which we could eat, but it's of so low energy content. This is this idea, you know.

We could basically do what gorillas are doing, sit down and munch the leaves. Many of these leaves are perfectly digestible, but they are digestible with difficulty. So it takes you a while to digest it. So this is why we have to kind of chew them and wait a long time and have a long gut, not as short gut as we have really. So basically these things have emerged. Again, this is evolution, evolution, evolution. We discovered by trial and error which plants are reasonably digestible,

which plants are highly edible, combined with relatively high yield, because part may be highly edible, but is a very low yield. Plant may have a high yield, but low digestibility, right? That's the problem is legumes, right? legumes are fine and we keep eating them, but legumes are notoriously hard to digest. So this is why we eat them in minor quantities. We eat lots of wheat, lots of fries, lots of corn, but we don't eat that much, whatever, peas, beans, soybeans, because there are so much more difficult to digest.

So everything is basically this evolutionary trial and error, and we have to get something which is a relatively high yield, good digestibility, and then you look deeper than also to survive. it has to combine the macronutrients. You have to get together carbohydrates and lipids and proteins and also mitonutrients. Because if you get all these three, and still no vitamins, no minerals, then you suffer mitochondrial deficiencies.

So it's a very complex effort how to combine all these things. And by a long evolutionary trial, we basically settled on this small bunch, 10, 20, depending on how to have 30 major plants which really feed the mankind. Rest of it, If it would disappear, it would be a pity from the variety point of view, but we wouldn't die.

But if you lose those 10, 12, 15 core plants, it would be gone. Obviously, no, rice, wheat, potatoes, corn, sorghum, and so on. So let's look into that, then. We call these staple foods, don't we? Yes, especially it's applied for staple cereals, because the cereals are the ones which have a relatively high yield, which could be, and it's another thing, of course, you know, because in places where you cannot cultivate year-round,

and you have to store all winter. Cereals of this advantage, then you dry them, you can store them in a bin or in a, now we do it in steel bins. We can store them in ceramic jar or something like that. So this is the combination. They are not very high in protein. I live in Manitoba. We have one of the best summer weeds in the world.

That wheat has 14% of protein. But normal soft wheat, which you grow in England over rinting wheat, someone are about 7% protein. So there is not much protein there, but there is enough there. So if you eat only wheat, basically, you will not be okay, but you can sort of make it because there is protein, there is a little bit of lipid and there is lots of carbohydrates. And same history of corn and same history of rice.

So this is why these grain staples became grain staples, because they combine these three things with relatively high yield, plus this storability over period when you cannot draw the crops. So this is how we ended up with them. Ambition comes in all shapes and sizes. At First Citizens Bank, we roll with your goals because we're built for what you're building. Fit for your ambition for Citizens Bank.

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Today, in partnership with French acoustic specialist's focal, name audio creates systems that deliver exceptional sound and unforgettable listening experiences at home. Try it for yourself at a focal powered by name boutique. Visit focal powered by name.com for more information. So in the book you talk at length about the efficiency of photosynthesis in different crops. So why is this such an important consideration?

Well, you know, it's fundamentally. That's so important because there is little, can do about it, you know. People think that, you know, the years over past 20 years improve because we somehow improve the efficiency. No, we haven't improved the efficiency at all. What we have done there, and this is one of the little secrets which I'm finding that so people are familiar with, that what we have done most importantly, that we have the proper biological term redistributed the photosynthate. 200 years ago, the plant were tall. You look at some of these pictures, you look at some of these pictures from Middle Ages,

from 16th century, when people are harvesting wheat or rye. They were up to their shoulders, up to their people are small, but still, they were basically as tall as people, 1.7 meters. And most of the biomass, above them biomass, because there is some consumes, most of them above down biomass was in straw, not in that grain, not in those ears of grain. So what we have done by breeding these things, we have redistributed the photosynthes, and now when you walk into the field of modern wheat, it's only about 40, 50 centimeters tall, instead of one, one and a half meter tall.

So there is much less straw, much more grain. So the efficiency of photoscindry basically hasn't changed, but the photosynthesis was channeled more into what you can eat instead of what you cannot eat really. And this is what happened with all grain crops. And this is the important thing. And plus, of course, we improve them by, you know, fertilizing, irrigating, so. But this is the most important thing that we redistributed the photos in-saintage. So before that, we used to have two units of straw or one unit of grain.

Now with wheat typically in the Western world, one unit of straw or one unit of grain, right? So it's now one-to-one. So this is the major achievement in terms of improving the productivity of grain crops. So let's look a bit more at modern farming methods. So for a long time, people have championed so-called organic farming. Yeah. I mean, what difference does that make? There is absolutely nothing wrong with organic farming,

because if it would have been, we would have to survive, because we had organic farming until late 19th century, because we did not have any artificial fertilizers. Then we got the phosphates, then we got the potassium, and eventually we got the synthesis of ammonia 1909, 1913, so we could make nitrogen fertilizers. But up to the time, it was totally organic. There is recycling, my wife.

which is now reading Zola's Belly of Paris, right, which is the beautiful book, which is basically based on organic recycling. You take the waste of Paris, no matter if it's, you know, the excrement, or if it's the cabbage leaves or uneaten food, and you just simply drag it out into Barnier and dump it on the fields, right?

And then you grow all the vegetables for the city of millions of people. But for that, you have to have the several important preconditions. You have to have lots of people who gather those organic bases, who let them ferment a bit, then load them and then bring them to the fields, right? Now the question today, you know,

we could do lots of organic farming, right? But very little you find those zillions of people taking care of these organic waste, gathering it, fermenting it, and lugging it to fields and applying it to fields. But even if you do so, right, you do the calculation, you find out that there is not enough organic matter around the world.

Even if I recycle every bit of straw, Every bit of animal and human experiment, mind you, there's a difficulty with human excrement, isn't it? It goes into major water treatment stations in every city, right? So, you know, how do you gather that? So you leave that around. But the thing is simply that there is not enough nitrogen. I've done these calculations many times. 35 years ago I wrote a book about harbable synthesis of ammonia.

Thanks to it, half of the humanities alike. Without it, we would have only about 4 billion people. Because simply as I say, I repeat it again, you guess all that nitrogen in all crop residues, in all organic waste, right? It gives you only about half as much nitrogen as it's needed to produce the food for 8 billion people. That's a pretty indisputable statement. So that's one fundamental problem is organic agriculture. That there is not enough nutrient. Now, mind you, you could feed probably even like six or seven billion people.

if those people would be eating mostly vegetarian diet. Because much of our food production is not a direct food production, but it's the production of food and feed for animals really. Because we eat so many animal products, not only meat, but also eggs and dairy products, whatever. So basically, that's the fundamental problem with organic agriculture, which is fine and works and could be quite productive. It's simply there is not enough organic method to recycle to feed 8 plus billion people. There is now very small percentage of people working agriculture.

So organic agriculture would require massive flow from cities to villages or to farms to do that physical recycling actually. And even then, you would gather lower yields. Because even when they're around, simply the organic agriculture will have almost always lower yield than our agriculture, which is subsidized by fertilizers, herbicides and so on. So as an idea or as a practice, there's absolutely nothing wrong with it. But again, the numbers that feed you for 8 billion people of whom very small person which now lives in villages and is willing to work in jobs like recycling, organic manure, it's a non-starter.

So you mentioned a lot there. So let's talk about ultra-modern farming methods, you know, hydroponics, vertical farming, and these sort of huge aircraft hangar-style buildings filled with large, and so on. Actually, that's an easy one, because it already plays a tremendous role dimensioning, this hangar type thing, or whatever. You look at Almeria, right, the south end of Spain. You can see from the satellite photos, it's all covered by the plastic.

And actually, it's now creeping into the hills above, you know, it's increasing. It's actually, so, and it's frightening, right? Because in summer you have like 30, 35 degrees Celsius there already, right? Now you put this under this thing, so inside it's like you are boiling. It's like 40, 45 degrees inside. The working inside is hell. But that already gives you people all around Europe, most of our vegetables out of the season, right?

They grow tomatoes, right? They grow peppers, they grow egg plants, all kinds of things. So already Almeria supplies the whole European continent with out of season, fruit and vegetables and some fruit. And that's fine, really, because people are willing to pay a high price for that vitamin C and that nice, color out of season, right? But that, of course, could never work, as you mentioned, like, you know, the buildings or either way, that could never work for staple crops. Again, the scale

that feeds you. Eight billion people, we now are growing more than two billion tons of staple grains. How can you grow two billion tons under the tent or in some six-story building? So in your six-story building your hydroponics, basil, lettuce, right? Cucumbers, fine, right? But basically what you are growing is just water, there is no nutrition to it, right? It's 95% of water, a little bit of vitamin C, and a little bit of some minerals, right? So this is just the thing. There is a place for these things, right? Especially when you have chips. Let's say if I have cheap solar electricity, why not to build that building, light it, you know, having it with 24-7, right, and grow some, uh, uh, uh, uh, Lettuce out of season, right?

No problem is that really. But you cannot grow corn or rice for 1.4 billion Chinese, 1.4 billion Indians under the plastic or in the six-story building under 24 hours a day later. So this is just the thing that we have so many nice inventions. And this is true about energy and materials as much as it is about agriculture, which work are admirable and are fine, but not for 8 billion people.

This is one of the things, which I'll keep returning to that. People have to record with the fact now that we have now this massive population, and not only it's massive, but it demands all kinds of things to me. So we can supply this 8 billion. Now, there is 8 billion mobile phones out there, right? Imagine that. 8 billion mobile phones, right? And these people every day, they eat whatever, 2,000, 2,500 kilo cars every day.

You have to supply them with this massive amount. So this is where these niche products, like, you know, frequently, it's almost as annoying as AI, of everything, future of the agriculture, and they show the tall building, and they show these nice stories, whatever. No, this is maybe the future of some vegetable on lettuce production, right? Not the future of grain and soyabins and corn and all potatoes for that matter, right? You need large chunks of land. You have to plow them.

have to feed them, you have to see them, and you have to wait for whatever, you know, 60, 90 to 150 days for that crop to mature under sunlight, right? So that's an easy one, you know. That is a niche role, but it will never feed the world, right? So whenever you see an article about, you know, hydroponics feeding the world, just turn the page, right? It will not. Thank you for listening to this episode of Instant Genius, brought to you from the team behind BBC Science Focus. That was Professor Vaclav Smil. To discover more about the topics we've just discussed, check out his latest book, How to Feed the World. If you liked what you just heard, then please do consider subscribing to Instant Genius on your preferred

podcast platform. The current issue of BBC Science Focus magazine is out now. Pick up a copy wherever you buy your favourite magazines or download us on your app store with choice. You can also find us on Apple News or on sciencefocus.com. This podcast is sponsored by name, audio and focal. The texture and emotional depth of music can be lost through digital sources or poor signal. Name Audio believes you can have digital precision with analog warmth. Alongside French acoustic specialist vocal, name creates high-end audio systems combining innovation with craftsmanship, so you can listen to music, just as the artist intended.

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