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I’m very concerned that if people don’t know about resilient foods then they could conclude that most people are going to die.

It could be an incentive for countries to do very bad things, like steal food from your neighboring countries.

That’s why I want to get the message out that we could actually feed everyone if we cooperate.

Dave Denkenberger

If there’s a nuclear war followed by nuclear winter, and the sun is blocked out for years, most of us are going to starve, right? Well, currently, probably we would, because humanity hasn’t done much to prevent it. But it turns out that an ounce of forethought might be enough for most people to get the calories they need to survive, even in a future as grim as that one.

Today’s guest is engineering professor Dave Denkenberger, who co-founded the Alliance to Feed the Earth in Disasters (ALLFED), which has the goal of finding ways humanity might be able to feed itself for years without relying on the sun. Over the last seven years, Dave and his team have turned up options from the mundane, like mushrooms grown on rotting wood, to the bizarre, like bacteria that can eat natural gas or electricity itself.

One option stands out as potentially able to feed billions: finding a way to eat wood ourselves. Even after a disaster, a huge amount of calories will be lying around, stored in wood and other plant cellulose. The trouble is that, even though cellulose is basically a lot of sugar molecules stuck together, humans can’t eat wood.

But we do know how to turn wood into something people can eat. We can grind wood up in already existing paper mills, then mix the pulp with enzymes that break the cellulose into sugar and the hemicellulose into other sugars.

Dave estimates that “…if hypothetically you were to feed one person all of their calories this way, it’s only about a dollar a day from cellulosic sugar. … It’s particularly cheap because we have these factories that have most of the components already. … Because we’re trying to feed everyone no matter what, we want to look at those resilient foods that are inexpensive.”

Another option that shows a lot of promise is seaweed. Buffered by the water around them, ocean life wouldn’t be as affected by the lower temperatures resulting from the sun being obscured. Sea plants are also already used to growing in low light, because the water above them already shades them to some extent.

Dave points out that “there are several species of seaweed that can still grow 10% per day, even with the lower light levels in nuclear winter and lower temperatures. … Not surprisingly, with that 10% growth per day, assuming we can scale up, we could actually get up to 160% of human calories in less than a year.”

But to get that sort of growth, humanity would need vast numbers of places for seaweed to attach, and to hang the strands close to the surface of the sea, where they can get the greatest amount of light. The solution is to attach it to ropes and suspend them from buoys that are anchored to the ocean floor but float on the top.

Dave’s team has estimated that “the main constraint here is twisting fibers into ropes that we’re going to attach the seaweed to. We found that right now, we don’t produce that much rope — we would actually have to increase our rope-twisting capability by 300 times, which sounds kind of crazy. But it’s actually a really simple process, and people have done it in their garage with a drill, basically twisting these fibers.”

Of course it will be easier to scale up seaweed production if it’s already a reasonably sized industry. At the end of the interview, we’re joined by Sahil Shah, who is trying to expand seaweed production in the UK with his business Sustainable Seaweed.

While a diet of seaweed and trees turned into sugar might not seem that appealing, the team at ALLFED also thinks several perfectly normal crops could also make a big contribution to feeding the world, even in a truly catastrophic scenario. Those crops include potatoes, canola, and sugar beets, which are currently grown in cool low-light environments.

ALLFED even thinks humanity could throw together huge numbers of low-tech greenhouses, which would stay 5–10°C warmer than the surrounding area and allow agriculture to continue similar to before. Cost is always the issue, but Dave expects the price of basic greenhouses wouldn’t be prohibitive: “…if we look at the cost of rice, we might add another dollar a day, so you might be up to $2 a day or something like that.”

Many of these ideas could turn out to be misguided or impractical in real-world conditions, which is why Dave and ALLFED are raising money to test them out on the ground. They think it’s essential to show these techniques can work so that should the worst happen, people turn their attention to producing more food rather than fighting one another over the small amount of food humanity has stockpiled.

In this conversation, Rob, Dave, and Sahil discuss the above, as well as:

  • How much one can trust the sort of economic modelling ALLFED does
  • Bacteria that turn natural gas or electricity into protein
  • How to feed astronauts in space with nuclear power
  • Jobs at ALLFED and what they’d do with more money
  • What, if anything, individuals can do to prepare themselves for global catastrophes
  • Whether we should worry about humanity running out of natural resources
  • How David helped save $10 billion worth of electricity through energy efficiency standards
  • And much more

Get this episode by subscribing to our podcast on the world’s most pressing problems and how to solve them: type 80,000 Hours into your podcasting app. Or read the transcript below.

Producer: Keiran Harris
Audio mastering: Ben Cordell
Transcriptions: Katy Moore

Highlights

Turning fiber or wood or cellulose into sugar

Dave Denkenberger: So we looked at constructing factories to produce this sugar very quickly, but what looks to be more promising is taking an existing factory that has a lot of the components we need and repurposing that to produce sugar. And one of the most promising we found was a paper factory, because it already takes wood, and it takes a lot of energy to grind it up and do that pre-processing step. And then it’s not that much more work to break the cellulose into edible sugars.

Rob Wiblin: Okay. So basically, should there be a nuclear winter or terrible volcano or something like that, we would still have a whole lot of wood and other plant matter that is just out there in nature. And there’s a lot of energy embedded in that, but the problem is humans cannot eat wood, so we need to find some way to make it digestible. And you’re saying it’s possible to turn it into the kind of sugar that we would normally eat. Like it’s possible to break it down into glucose and then we can eat that?

Dave Denkenberger: That’s right, and there are actually a couple startup companies that are trying to turn fiber into edible sugar. Now that’s great, because they’re doing some of this research, but they’re just not thinking how we would do it fast in a catastrophe. And so that’s the type of research that we’re looking at.

Rob Wiblin: So what’s the process for taking a bunch of wood and then turning it into something that people can eat?

Dave Denkenberger: Basically a lot of grinding in the beginning, break it up into pieces. We call it “lignocellulosic material,” and that comes from the cellulose, which is basically lots of sugar molecules stuck together. There’s also hemicellulose, which is similar, and then there’s lignin — which you can’t really do anything with lignin, so you need to separate those components. And then you apply an enzyme to break the cellulose into sugar and the hemicellulose into other sugars.

Rob Wiblin: Is this with a bacteria or do you use chemicals to break it down?

Dave Denkenberger: It’s typically done where you’ll purify an enzyme that is produced by an organism like a fungus or bacteria, but then it’s done without that organism in a bioreactor.

Rob Wiblin: Okay. So I guess fungus eats logs, and there’s probably bacteria that eat logs as well. And I suppose they also probably can’t directly absorb cellulose or anything like that, so they themselves have to break it down into sugar somehow, right? And if I remember from my biology class, fungus extrudes some sort of acids or other compounds that break down wood into something that then the fungus can absorb and use to get energy. Are we to some degree mimicking that process to make something that humans can also eat?

Dave Denkenberger: Exactly. As we mentioned, mushrooms are one way of turning wood into food, but it turns out they’re pretty inefficient. And so if we can just grab the enzymes from them and then turn all that cellulose into sugar, or nearly all, we get a lot more food out of it than with the natural process.

Rob Wiblin: How expensive would this be? Is this a way that we could plausibly make food at an affordable price today?

Dave Denkenberger: Yeah, amazingly inexpensive, even though we’d be doing this repurposing with 24/7 labor — we would have to pay more for that. And even considering the fact that we wouldn’t run these factories as long; we’d probably only be running them for 10 years during the catastrophe. That increases the cost, but not that much. And so if you were to feed one person all of their calories — which obviously they wouldn’t eat all their calories, but it’s a way of visualizing it — it’s only about a dollar a day from cellulosic sugar. And that’s our target here, because we’re trying to feed everyone no matter what. We want to look at those resilient foods that are inexpensive.

Redirecting human-edible food away from animals

Dave Denkenberger: We feed a lot of food to animals. And yet many animals, as I pointed out, can eat stuff that’s not edible to humans. So in a catastrophe, we would want to redirect that human-edible food away from animals as fast as possible. And so we’re looking at scaling up having animals eat the residues from agriculture.

Rob Wiblin: So this is like the leaves on wheat plants or something like that?

Dave Denkenberger: That’s right.

Rob Wiblin: That people can’t eat. How much energy is in all of the agricultural residues?

Dave Denkenberger: It’s quite big and a lot of people are looking at it as a source of fuel, and that’s where the cellulosic biofuels are looking at.

Rob Wiblin: Yeah. I guess to some extent, we’re trying to plan for a world where there isn’t agriculture, or it’s going to be hard to grow the wheat to get the leaves and so on. But I guess there’s tons of that material just lying about already on farms that we could then potentially feed to cows or pigs or so on. And there’s also just trees out there, so you can get lots of leaf matter and try to feed them to animals that would then eat that.

Dave Denkenberger: That’s right. But interestingly, even in a pretty severe nuclear winter… The technical terminology here refers to how much soot or black carbon gets injected into the stratosphere: 150 teragrams or 150 million tons is a bad nuclear winter, with eight degree Celsius loss within a year. But still you have about 40% as much light coming through, so we might be able to actually grow something photosynthetically. Just moving on from the ruminants, even in places where you have a really short growing season, you might not be able to grow crops. But you might be able to grow grass, so there could be some grazing continuing.

Rob Wiblin: Why don’t we feed these byproducts that presumably aren’t earning much revenue right now to cows and pigs and chickens? It’s a bit odd that we’re not feeding them this thing that is kind of useless rather than feeding them food that humans could potentially eat.

Dave Denkenberger: It’s a good question. And I think part of it is that, at least in the US, there’s a subsidy for corn or maize. So that makes it more economical for the ranchers to, say… Typically you do grazing early life of the cattle and then fatten them up on maize later. And so if they didn’t have that subsidy, they probably wouldn’t be doing as much feeding them human-edible food. And I think long term, as we need to get more sustainable, we need to get more food out of the same land, I think we will move more towards utilizing these agricultural residues.

Rob Wiblin: Yeah. Interesting. Okay, so there’s possible subsidies. I suppose also just calories from corn is so cheap now that if there’s practical downsides — maybe health-related downsides, or just practical issues getting the agriculture residues — if there’s any kind of downsides, maybe the feed is so inexpensive anyway that you’ll just go with the thing that’s most straightforward and most familiar.

Dave Denkenberger: Right. The cattle would not mature as fast. And so time is money here.

Seaweed production

Dave Denkenberger: There are several species of seaweed that can still grow 10% per day, even with the lower light levels in nuclear winter and lower temperatures.

Rob Wiblin: Even up to adulthood? They just keep growing at 10% a day?

Dave Denkenberger: They just keep growing. So basically you have these long lines that are floated by these buoys, and you start with little pieces of seaweed and they grow and then you just chop off the growth and then they just keep growing.

Dave Denkenberger: It is amazing. And it’s only certain species, and right now they’re often limited by nutrients. So at least in the near term, we would still have those nutrients. I talked last time about the potential overturning of the ocean — that if you cool the upper layers of the ocean, they sink and bring up nutrients. So it turns out that is not as large as I thought it was going to be, so the actual production from fish is not going to go up as much as I thought. But with seaweed, it’s just much more efficient, growing it directly, than having algae grow and then feeding it to fish.

Rob Wiblin: What kind of inputs do we need in order to grow much more seaweed? I guess you’ve got to be around a coast, and then you were saying to grow seaweed, you attach it to ropes? It’s a bit like rope-grown mussels or something like that.

Dave Denkenberger: Yes. So it turns out we produce a lot of synthetic fiber for other reasons, like clothing. The main constraint here is twisting those fibers into ropes that we’re going to attach the seaweed to. We found that right now, we don’t produce that much rope — we would actually have to increase our rope-twisting capability by 300 times, which sounds kind of crazy. But it’s actually a really simple process, and people have done it in their garage with a drill, basically twisting these fibers. But these pieces of equipment are only like $10,000 and you can make a lot of rope, so it turns out it takes a very small percent of our manufacturing budget to make a lot of rope twisters.

Rob Wiblin: I mean, most seaweed is growing out of the ocean bed on rocks and things like that, right? It attaches to something on the bottom and then it grows upwards. But that’s no good for us? I guess all of that seaweed that can attach to rocks on the bottom of the coast, that’s already growing, so we need to have some artificial environment that’s very conducive to seaweed growing. And I suppose the closer it is to the surface, the more light it’s getting, so it might grow faster if we are attaching it to ropes near the top.

Dave Denkenberger: That’s right. So seaweed, why it can handle low light levels, is it often does grow 10 meters down in the ocean. But yeah, we want to have it near the surface in nuclear winter.

Rob Wiblin: Yeah. Okay. So the limiting factor is ropes that you’ll be hanging out of boats and things like that?

Dave Denkenberger: Yeah. So you’d be taking the rope and you’d be attaching small pieces of seaweed to it. Then you string the rope out in the ocean, and it’s held upward by buoys and then also anchored at the end.

Rob Wiblin: What fraction of food do you think we might be able to get from seaweed ultimately?

Dave Denkenberger: Not surprisingly, with that 10% growth per day, assuming we can scale up that rope twisting, we could actually get up to 160% of human calories in less than a year.

Barriers to seaweed farming in the West

Sahil Shah: We essentially see the problem as one of unit economics. So we are looking at using a high amount of mechanization — both when it comes to seeding and harvesting, developing new types of seeding techniques and purpose-built vessels — as well as trying different types of materials to grow the seaweed on, which can increase yields and improve composition. As well as different types of mooring systems, which would be different to ropes — again, which would have higher yields and higher amounts of mechanization.

Sahil Shah: The main reason why it’s not grown as much in the West as it is in China and Indonesia is to do with cost and price. Seaweed here is generally seen as a luxury good, if you want to buy sea vegetables anywhere. And effectively having something more industrial than artisan means that it would open up a wide variety of new uses that we would be able to then supply to and increase the market as a whole.

Sahil Shah: I think another aspect that I would add to that is biological. We don’t understand as much about seaweed as we do about traditional crops. The genes haven’t been sequenced in the same way. We’re not able to manipulate the genome because seaweed can kind of break free and it can move about in the ocean.

Sahil Shah: There’s a very different risk profile of introducing new genetically modified strains. So those are one of the elements where it has been done in China, and actually Chinese seaweed farmers are able to engineer and grow crops that are substantively larger and substantively cheaper. But outside of China, there are regulatory barriers — understandably so — around gene-editing modification, which you don’t have to the same extent on plant-based crops, and which really do contribute to production and cost of production.

Rob Wiblin: What sorts of regulations would you like to see changed in the UK?

Sahil Shah: I think there are quite a few. One is that the barrier of proof that there won’t be a negative impact is particularly high. So it can take years and tens of thousands, if not hundreds of thousands of pounds to actually get a seaweed farm in the water.

Sahil Shah: The second thing I would add is carbon credits, where some really interesting work has been done, and is being done predominantly by a nonprofit called Oceans 2050. But when seaweed grows, especially the large kelps, up to 50% of the biomass can actually fragment down to the ocean floor, where it effectively becomes long-term sequestered. At the moment, this is very difficult to monitor and track, and there are no carbon credits available. If that were to then change and policy were to change with it, it would suddenly make the unit economics much more attractive.

Global cooperation

Dave Denkenberger: Certainly a concern here is that our initial modeling is assuming global cooperation. The UK has a lot of potato seed, and they wouldn’t be able to grow them themselves — would they actually trust another country to grow the potatoes and then give them back more food than originally? So ideally we could actually talk about some of these agreements ahead of time so that people could be pre-committed to it.

Dave Denkenberger: But certainly we are concerned about cooperation breaking down. We’re going to be moving into more regional geographic information systems (or GIS) analysis, looking at the resources of individual countries from a resilient food perspective, and then actually working out what would happen if international trade turned off — it would be much worse. What we’re hoping to do is use that information to convince governments to actually cooperate.

Dave Denkenberger: In the past — say 2007, 2008 — the actual food production shortfall was less than 1%. But because of countries doing export bans, rice price went up three or even four times. So it’s a major risk, restriction of trade. There’s even potential of restricting more than just food trade, if we lose that trust and cooperation. And that would be just catastrophic, because then you lose energy trade and minerals and components — and the supply-chain issues we’ve seen in COVID are nothing compared to that.

Rob Wiblin: Do you have an intuition for if there was a supervolcano eruption, whether humanity would mostly pull together? I don’t know. I suppose we’re going to talk about COVID-19 in a minute, but my sense was cooperation during COVID-19 was pretty good, and it could be even better during a volcano situation.

Dave Denkenberger: Potentially. I’m very concerned that if people don’t know about resilient foods then they could conclude that most people are going to die. It could be an incentive for countries to do very bad things, like steal food from your neighboring countries. So I am very worried about that, and that’s why I want to get the message out that we could actually feed everyone if we cooperate.

Dave Denkenberger: And this country-by-country analysis: if we can know roughly what each country has in terms of resources, we could actually give them a draft plan. Now of course they’ll say it’s wrong because of this reason, and you don’t know this classified information — but we’re kind of jump starting them, and then hopefully they would actually have a viable plan to respond quickly.

Overlap with space industries' need to feed people in space

Dave Denkenberger: I think there’s potential overlap. It is at a quite different scale. I would say that one potential overlap with global catastrophic risk would be the really extreme scenarios where potentially everyone has been killed, that you can think of, “Can we make a refuge with 1,000 people that might be able to repopulate the Earth?” And Elon Musk is interested in doing this on Mars, so if we could figure out how to make an independent colony on Mars with fewer people, and with less expensive, less infrastructure-intensive food production, then I think that could have some existential risk benefits.

Rob Wiblin: Yeah. I guess another option is doing that somewhere really remote on Earth, like under the sea, or in Antarctica or so on — where you’d also have to figure out how to feed people in a worst-case scenario. It sounds like you could potentially use a nuclear reactor to grow bacteria and then eat them — or otherwise just have stores of fossil fuels, or put it somewhere where you have access to fossil fuels — and then you could in theory eat that.

Dave Denkenberger: Yeah, that’s right. So again, if you look at the plans for having an underground bunker — typically nuclear — the plans were to go through regular plants and that’s really inefficient, so we could lower the cost of this significantly.

Rob Wiblin: Yeah, so it was either you have this enormous initial cost of stockpiling all the food and making it big enough to store food to feed everyone for ages, or you’ve got this horrifically inefficient process of converting electricity into human-edible food that now we can do 10x better on.

Dave Denkenberger: And the other thing if you use the stored food is that you’re breathing out carbon dioxide and you need oxygen. Whereas if you have a system that actually grows food — either plants, which is of course inefficient, but these space-based resilient foods if you want to call them that — they can act as the life support system, because they would actually take the carbon dioxide from the astronauts to make the food and then they produce oxygen.

Dave Denkenberger: I guess another extreme scenario is a runaway climate change scenario, where it might get too hot for plants to live. So that’s another scenario where having these types of “space foods” could be a good food source.

Rob Wiblin: Interesting. God, it could be a very bizarre future, I suppose. Mostly just eating bacteria grown in electricity. Again, it sounds like absolutely bizarre sci-fi stuff. I kind of can’t believe that it actually works, but sounds like in principle it could.

Should listeners be doing anything to prepare for possible disasters?

Dave Denkenberger: Well, there’s a general recommendation of having two weeks of food. And you can justify that just based on an extended hurricane outage, so I think that’s pretty obvious. I personally don’t store more food than that because I’m more interested in keeping the whole system functioning.

Dave Denkenberger: But another thing I do think about is that I think there is a significant risk of full-scale nuclear war. And so I’m personally concerned that so many people in the effective altruism community are living in typically the city centers of NATO cities. And it’s interesting that their typical city real estate prices are such that it’s more expensive to live in the city center than in the outskirts, because in the outskirts you have a long commute.

Dave Denkenberger: But this gradient in real estate price is generally not taking into account the risk of nuclear war, because most people just ignore it. So you could potentially exploit this. And if you are concerned about the risk of nuclear war, living further away could be optimal, especially if you could have a commute where you could multitask.

Rob Wiblin: Yeah, right, right, right. Or I guess now, if you can work remotely.

Dave Denkenberger: Exactly.

Rob Wiblin: People spreading out because it’s harder for everyone to get killed that way. Yeah you’re right. And I guess a lot of listeners to this show, I can see in the analytics that a lot of people are in London, Oxford, SF, LA, New York, Sydney, Berlin. Yeah, all probable targets. Except maybe Sydney. I’m not sure about Sydney. Well, maybe once they have these nuclear submarines that they’re talking about, then they’ll target Sydney as well. Interesting idea. How far away do you have to live from a city center to not get toasted?

Dave Denkenberger: It really depends on how many nuclear weapons are used and whether it’s just the US as the target or all of NATO. But I think that just living on the outskirts of a city is quite a bit lower risk.

Rob Wiblin: Easy enough. Okay, nice.

Dave Denkenberger: And you could also live in a smaller city, but that might not always be feasible.

Articles, books, and other media discussed in the show

Dave’s work:

Sahil’s work:

  • Food Systems Handbook — an open source project by Sahil Shah, Aron Mill, Uri Katz, Edward Saperia, and others

Books and articles on resilient foods:

Organisations and companies working in this space:

Other 80,000 Hours Podcast episodes:

Everything else:

Transcript

Rob’s intro [00:00:00]

Rob Wiblin: Hi listeners, this is the 80,000 Hours Podcast, where we have unusually in-depth conversations about the world’s most pressing problems, what you can do to solve them, and whether my food truck that exclusively serves electricity-eating bacteria will be a hit. I’m Rob Wiblin, Head of Research at 80,000 Hours.

I first interviewed Dave Denkenberger about how to feed the world through a catastrophe that interfered with agriculture 3 years ago in episode 50 of the show.

Listeners loved it because of the creativity and ambition Dave showed when it came to solving problems. He’s the kind of person to do a cost-effectiveness estimate and take what it says seriously.

Dave’s research and non-profit, called the Alliance to Feed the Earth in Disasters (ALLFED), have come a long way since then, so Keiran and I thought it was time to check in and see what was new.

It turns out the answer is a lot — ALLFED has had time to look into some food sources that were more just ideas back in 2018. This time I came away thinking that feeding the world through disasters might be far easier than people think, and that it’s pretty crazy humanity isn’t much more on top of all these methods given the value for money they might offer.

We do a decent recap at the start so there’s no need to listen to our first conversation in episode 50 first.

If you’re already familiar and want to skip the recap of what resilient foods are and why they might matter so much, you should skip about 11 minutes into the episode.

I’m happy to say we’re joined at the end of the conversation by David’s colleague, Sahil Shah, who is an economist and co-founder of a company called Sustainable Seaweed. It turns out seaweed is much cooler than I realised, and Sahil is trying to find ways to expand the seaweed industry by building a business that can fund its own expansion. He also fills us in on the impact COVID and a locust plague have had on famine and food prices in recent years.

Dave and ALLFED are fundraising at the moment in order to be able to pursue more of the lines of research covered in today’s episode. If you’d like to donate, which I think would be a very reasonable decision, then head to ALLFED.info/donate or contact David at [email protected] They accept crypto and can offer tax deductibility in a number of countries. ALLFED is also hiring-you can check out jobs at ALLFED.info.

Just a final note — if you’re listening to this episode the day of release Giving Tuesday is November 30 and you can potentially get your donation to ALLFED and dozens of other organization matched at 8 AM US Eastern time. Learn more about that at www.eagivingtuesday.org.

Alright, without further ado, here’s Dr David Denkenberger.

The interview begins [00:02:36]

Rob Wiblin: Today I’m speaking with Dave Denkenberger. He did his undergraduate in Engineering Science at Penn State on a National Merit Scholarship, before doing a master’s at Princeton in Mechanical and Aerospace Engineering and a PhD at the University of Colorado at Boulder in their Building Systems Engineering program on a National Science Foundation Graduate Research Fellowship. He’s now an assistant professor at the University of Alaska Fairbanks in Mechanical Engineering.

Rob Wiblin: In 2017, he co-founded and now directs the Alliance to Feed the Earth in Disasters, otherwise known as ALLFED, and he donates half of his income to it. He has authored or coauthored 110 publications with over 2,800 citations between them. And among that, there is the book Feeding Everyone No Matter What: Managing Food Security After Global Catastrophe, which was the main topic of our conversation back in episode 50 from 2018. Thanks for returning to the show, Dave.

Dave Denkenberger: Thanks Rob. Great to be back.

Rob Wiblin: Later on we’re going to be joined for a while by your colleague Sahil Shah, to talk about his work on seaweed, disaster financing, and food security during COVID. But I find it’s often a bit easier to properly dive into technical issues with just one person, so we’re going to start and end the conversation with just the two of us. And for that, I hope to talk about how ALLFED and our options for feeding humanity without the sun have progressed over the last three years. But first, as always, what are you working on at the moment and why do you think it’s important?

Dave Denkenberger: Well, now that ALLFED has grown quite a bit, I’ve been transitioning from doing a lot of research to managing research, which I also really enjoy. And I’m particularly excited about integrating food sources together and looking at the economics — people being able to afford it — and then also eventually look at different cooperation scenarios, the politics of it.

Rob Wiblin: Nice. How big is ALLFED these days compared to 2018, in terms of the number of people involved and the budget?

Dave Denkenberger: We’ve definitely grown a lot. We’re around 10 full-time equivalent paid, but we also have a large number of volunteers, a couple dozen, and it’s been great.

Resilient foods recap [00:04:27]

Rob Wiblin: Excellent. Okay, so quite a lot of listeners I think might have heard our interview from back in 2018, but plenty won’t have. And I suppose of those who heard it back in 2018, over the last three years they might have forgotten a few of the little details. So do you mind just reminding everyone of what are resilient foods, and what’s the case for working on them?

Dave Denkenberger: Sure. I guess when I started surveying global catastrophic risks and looking at what might be done about them, I was reading this paper called “Fungi and Sustainability,” and they observed that with the dinosaur-killing asteroid, there were lots of dead trees and the sun was blocked, but mushrooms could grow. And they said, “Maybe when humans go extinct, the world will be ruled by mushrooms again.” And I said, “Well, wait a minute. Why don’t we eat the mushrooms and not go extinct?”

Rob Wiblin: Makes sense.

Dave Denkenberger: And so it started there, but then expanded out: “What other resilient foods could actually work without the sun?” And when people had looked at this before, they thought, “Just store up a lot of food ahead of time.” And that would work, but it would probably cost tens of trillions of dollars, and it would take a long time to store up the food. And if you tried to do it fast, the food price would go up a lot, so more people would starve in the near term. So I was interested in if we could do something that doesn’t cost too much ahead of time, and then just spend the big money if and when the catastrophe comes.

Dave Denkenberger: Mushrooms are great, but they’re not the cheapest source of calories. So in the book Feeding Everyone No Matter What, we looked at a number of different possible foods, including turning wood or fiber into sugar, methane, or natural gas–consuming microbes that have a lot of protein that we could eat. And then some animals, often called ruminants — like cows, sheep, and goats — could eat dead leaves and produce some food. The leaves that are killed by the catastrophe would still have some protein in them, so we might be able to grind them up and get that protein out. Other possibilities included insects and rats.

Rob Wiblin: I suppose none of these things sound incredibly appetizing, but they probably all sound a bunch better than starvation.

Dave Denkenberger: Yeah, and some of them are more conventional, like cow’s milk and sugar.

Rob Wiblin: Yeah. Cool, so the background is that there’s a whole lot of ways that humanity could end up with a big food shortfall at some point in the next few centuries. I guess one that people will be very familiar with — that we’ve talked about on the show quite a lot — is the possibility of a nuclear war, and then a nuclear winter that dramatically interferes with agriculture. I guess volcanoes in the past have interfered with agriculture, and asteroids, should we be really unlucky, could do that.

Rob Wiblin: And another one that’s a bit more salient than when we spoke in 2018 is the possibility of a pandemic that has a sufficiently high fatality rate that people just don’t want to go out and do any work, because that exposes them to the pathogen and the risk of death, and so that interferes with agriculture or the transportation of food. And there’s other possibilities, like weeds, or just incredibly bad weather, or climate change getting worse dramatically, or even gradually all of these things could interfere with food, which is such an important thing for humanity. So we kind of want to have a backup plan of how would we try to feed everyone no matter what, basically.

Dave Denkenberger: That’s right.

Rob Wiblin: As you were saying, we could stockpile lots of food. The problem with that is that we would have to be doing that all the time — storing all of this food and paying to basically have enough food to feed humanity for a whole year. And we’d have to do that regardless of whether there is a disaster, whether a disaster eventuates or not. So it would be much nicer if we could just spend all this money if, and only if, there actually is a disaster that requires it. It’s a lot cheaper to have this plan on the shelf that you could pull off and implement and scale up really quickly, should it come to that.

Dave Denkenberger: That’s right. And it could potentially be five or even 10 years — especially with the nuclear winter, the dark particles could stay in the stratosphere a long time. So even though there are some countries that might have six months or a year, none are ready for these really long catastrophes.

Cost effectiveness recap [00:08:07]

Rob Wiblin: Yeah. Okay, so we’re going to talk about the potential cost effectiveness of this project in terms of lives saved per dollar later on. But just briefly, do you want to recap some of the analyses that you’ve done of that over the years?

Dave Denkenberger: Sure. There have been really two different timescales that we’ve looked at. One is the near-term timescale: can we save lives cost effectively in the present generation? But then also looking at the long-term future impact: that is, there are a number of mechanisms that a catastrophe like nuclear winter could affect in the long term. And so I certainly agree with recent guest Carl Shulman that we can justify investment in these catastrophes just based on the present generation. But then as many of your listeners are concerned about the long term, I think there are a number of mechanisms that a catastrophe like nuclear winter could affect in the long term.

Dave Denkenberger: And so you just had Luisa on the podcast recently, and she went into great detail about probabilities of collapse and recovery. And I think she makes a lot of good points. I think that direct extinction from these catastrophes is quite unlikely. I would say that it’s possible that… There was this book called The Secret of Our Success, which looks at examples of people in a more developed circumstance trying to go back to hunter-gatherers, and it often didn’t go well. So even though we’d have some stored food of course — and some people would survive on that — if we couldn’t figure out how to go back to being hunter-gatherers, if we’d lost that civilization, that might not go well.

Dave Denkenberger: Then of course we have a lot of current hunter-gatherers, but they don’t have a lot of stored food, so it might not be clear that they would make it through. Of course there is fishing as well, but if you have many more people than food supply, there’s a risk that we would actually eat species to extinction. And then you have no other alternative. So I don’t think it’s very likely, but I think there is some mechanism.

Dave Denkenberger: Then the other thing about, if we lost civilization, would we recover it? I am quite optimistic that we’re likely to recover. But even if it’s a 1% chance we don’t recover, I still think that there’s a case from the long-term perspective to invest in this. I think that nuclear winter is likely enough and the amount of money we’re talking about is relatively small. And so this cost-effectiveness analysis was compared to artificial general intelligence safety — and there’s tons of uncertainty — but I think what we can say is that they’re at least in the ballpark, and so we should be investing in both of them.

Rob Wiblin: Yeah.

Turning fiber or wood or cellulose into sugar [00:10:30]

Rob Wiblin: Let’s maybe push into what’s happened in the last three years. I think last time around we spoke about mushrooms, seaweed, algae, processed plant matter… I guess seafood, which is not interrupted as much as agriculture. We briefly talked about direct synthesis of food from fossil fuels; potatoes, which grow pretty well in the cold; growing bacteria from methane; and there was also the possibility, which I think we hadn’t really looked into back in 2018, of fermenting plant matter using yeast or bacteria or fungus. So this would be plant matter that would still be around and potentially rotting, because of the absence of the sun. Do you want to give us an update on one of those options that has progressed a little bit since we last spoke?

Dave Denkenberger: Sure. So one of the things we’ve done is look at the current costs of these resilient foods’ production, because many of them are already in production. And that gives us some idea of how cost effective they might be — though of course the actual catastrophe could change things. And in the catastrophe, it might not be so much that it is dollars that we’re talking about, but how many resources go into it. And I think that’s correlated now with the current price, and so that allows us to prioritize.

Dave Denkenberger: And one of the technologies that came out as promising is turning fiber or wood or cellulose into sugar. So we looked at constructing factories to produce this sugar very quickly, but what looks to be more promising is taking an existing factory that has a lot of the components we need and repurposing that to produce sugar. And one of the most promising we found was a paper factory, because it already takes wood, and it takes a lot of energy to grind it up and do that pre-processing step. And then it’s not that much more work to break the cellulose into edible sugars.

Rob Wiblin: Okay. So basically, should there be a nuclear winter or terrible volcano or something like that, we would still have a whole lot of wood and other plant matter that is just out there in nature. And there’s a lot of energy embedded in that, but the problem is humans cannot eat wood, so we need to find some way to make it digestible. And you’re saying it’s possible to turn it into the kind of sugar that we would normally eat. Like it’s possible to break it down into glucose and then we can eat that?

Dave Denkenberger: That’s right, and there are actually a couple startup companies that are trying to turn fiber into edible sugar. Now that’s great, because they’re doing some of this research, but they’re just not thinking how we would do it fast in a catastrophe. And so that’s the type of research that we’re looking at.

Rob Wiblin: So have people done this before? Have people turned wood into sugar ever or is this…?

Dave Denkenberger: In fact, the second-generation or cellulosic biofuels do just that. But then they take the sugar and ferment it into ethanol to substitute for gasoline or petrol. And in that case you’re not worried about food standards, but you are making actual edible sugar.

Rob Wiblin: Interesting. Okay, so what’s the process for taking a bunch of wood and then turning it into something that people can eat?

Dave Denkenberger: Basically a lot of grinding in the beginning, break it up into pieces. We call it “lignocellulosic material,” and that comes from the cellulose, which is basically lots of sugar molecules stuck together. There’s also hemicellulose, which is similar, and then there’s lignin — which you can’t really do anything with lignin, so you need to separate those components. And then you apply an enzyme to break the cellulose into sugar and the hemicellulose into other sugars.

Rob Wiblin: Is this with a bacteria or do you use chemicals to break it down?

Dave Denkenberger: It’s typically done where you’ll purify an enzyme that is produced by an organism like a fungus or bacteria, but then it’s done without that organism in a bioreactor.

Rob Wiblin: Okay. So I guess fungus eats logs, and there’s probably bacteria that eat logs as well. And I suppose they also probably can’t directly absorb cellulose or anything like that, so they themselves have to break it down into sugar somehow, right? And if I remember from my biology class, fungus extrudes some sort of acids or other compounds that break down wood into something that then the fungus can absorb and use to get energy. Are we to some degree mimicking that process to make something that humans can also eat?

Dave Denkenberger: Exactly. As we mentioned, mushrooms are one way of turning wood into food, but it turns out they’re pretty inefficient. And so if we can just grab the enzymes from them and then turn all that cellulose into sugar, or nearly all, we get a lot more food out of it than with the natural process.

Rob Wiblin: That makes a ton of sense. How expensive would this be? Is this a way that we could plausibly make food at an affordable price today?

Dave Denkenberger: Yeah, amazingly inexpensive, even though we’d be doing this repurposing with 24/7 labor — we would have to pay more for that. And even considering the fact that we wouldn’t run these factories as long; we’d probably only be running them for 10 years during the catastrophe. That increases the cost, but not that much. And so if you were to feed one person all of their calories — which obviously they wouldn’t eat all their calories, but it’s a way of visualizing it — it’s only about a dollar a day from cellulosic sugar.

Rob Wiblin: Why is it so cheap? Is it just that wood has a whole lot of calories in it and there’ll be lots of wood around? And it’s actually, just from an industrial perspective, not that difficult to process it into sugar?

Dave Denkenberger: Yes. So you’re not paying for the energy because it is a waste product, whereas with some of these other sources you’re paying for the energy. And then it’s also particularly cheap because we have these factories that have most of the components already.

Rob Wiblin: Right. Okay, so it was paper factories, I guess obviously they have to be processing wood. Are there other factories that have similar capacity to kind of grind things up and then put them in a vat with some enzymes?

Dave Denkenberger: Another one is breweries.

Rob Wiblin: Yeah. Okay. That makes a lot of sense. Are there going to be issues with bacteria invading the vats here, or are the enzymes sufficiently caustic that you wouldn’t have a problem with invading pathogens?

Dave Denkenberger: As far as I know it’s not a significant problem. We also looked at how many people might be fed from this source. And so we looked at a kind of extreme scenario: what if you were to repurpose all the paper factories? Obviously we wouldn’t do all of them, but it gives you some idea. And then we looked at how much are we currently spending to make similar things — factories that are related to chemical and mechanical processes. And that was around $500 billion a year. So we said, “What if we repurpose this construction budget to repurposing paper factories?” And we found that by the end of the first year, we could provide calories for approximately 30% of the population.

Rob Wiblin: Okay. So this is if we redivert a lot of our industrial capacity into making factories that can produce this glucose from wood, then within a year we could feed about a third of the world using this method?

Dave Denkenberger: That’s right.

Rob Wiblin: And incredibly cheaply it sounds like as well — a dollar a day per person is affordable even for people who are quite poor.

Dave Denkenberger: Exactly. And that’s our target here, because we’re trying to feed everyone no matter what. We want to look at those resilient foods that are inexpensive.

Rob Wiblin: Okay. So this method sounds incredibly good: it’s cheap, it’s pretty scalable, we can repurpose a lot of equipment that’s already around, and it doesn’t sound like it’s technically that complicated. Are there any downsides that we should be aware of? Or should we be really, really bullish about this method?

Dave Denkenberger: The major downside is that if we were to repurpose many of the paper factories, the cost of paper would go up. And so this analysis is not taking into account the opportunity cost of paper production. Now what I’ll talk about later is what we call the “integrated model,” where we’re actually looking at the interactions between the resilient foods, and that would actually take into account that opportunity cost.

Rob Wiblin: Yeah. I mean I feel like in a nuclear winter, we don’t want paper so much, or I feel like I would take the food over the paper. Can’t we just scribble stuff on blackboards or something?

Dave Denkenberger: And maybe recycle paper. So yeah, hopefully we could dramatically reduce the production of paper.

Rob Wiblin: Yeah. So we have all this industrial stuff for grinding up wood for various different reasons. But what about making all of these enzymes, is that a more technically challenging thing if we’re producing the enzymes through some biological process?

Dave Denkenberger: Well, that’s all included in the cost, and one nice thing about using bacteria or fungi is they can be scaled up quickly, so it’s really limited by installing the equipment.

Rob Wiblin: Yeah. I guess presumably at the end of this process, you would have some stage at which you pull out the sugars and then separate out the enzymes that you were using — that would just be part of the food processing. So potentially the enzymes could be reused for quite a substantial period of time before you’d have to replace them.

Dave Denkenberger: Right. I would also comment that in the book, we did this order of magnitude technical scaling capability of these different resilient foods. And my original estimate was actually feeding everyone by the end of the first year, so we’re lower than that. But I would point out that this is just the factory construction budget that’s quite relevant to this process. It’s possible that we could take people who are building roads or buildings and train them how to build factories. But that would be more involved and we haven’t worked out the costs in that case.

Rob Wiblin: How many people could we feed with kind of the current paper-producing capacity and other infrastructure that’s already just there?

Dave Denkenberger: That’s the 30%.

Rob Wiblin: That’s the 30%? Oh right. Sorry, I thought that that was if you actually built new stuff?

Dave Denkenberger: That’s only repurposing.

Rob Wiblin: That’s just repurposing? Okay, and what happens if we’re like, “Well, let’s make some new factories”?

Dave Denkenberger: Well then we can feed more. But if we’re already getting 30% of our calories from sugar, we might not need any more sugar.

Rob Wiblin: Okay, I see.

Dave Denkenberger: So then, what I would do as the next thing is I would build new factories that can turn the methane into single-cell protein. And there we did not find a good repurposing opportunity, because it was pretty specialized equipment, so then we would be building the factories from scratch. So again, we’re looking at fast construction that’s going to cost more, and we’re only going to use them a certain amount of time, but still it’s a pretty low-cost way of producing calories, and they’re 50 to 80% protein.

Rob Wiblin: Right. So this is where you have a suspended liquid, and you’re growing these bacteria that are able to directly eat methane. I guess we’ve gotten them from vents or other locations where methane is abundant, and they’ve learned to basically just eat methane out of their environment.

Dave Denkenberger: Right.

Rob Wiblin: And so you bubble up methane I guess. And we get methane the same way we get natural gas, is that right?

Dave Denkenberger: Methane is the primary component of natural gas. Though it is possible that we could use a biogas instead of a fossil fuel.

Rob Wiblin: Okay. So we got methane that we were previously using to heat homes. We bubble it through a liquid that has this bacteria growing in it, and the bacteria just eat the methane and turn it into food — importantly, protein, which otherwise might be a bit challenging to get.

Dave Denkenberger: That’s right, you’re not getting any protein from that sugar. And by the end of the first year, we’ve estimated that — again, with that repurposable budget of construction — we could provide about 20% of global protein requirements.

Rob Wiblin: And the repurposing there, you’re saying we don’t have tons of equipment that could be used for this lying about. So we would actually have to start building new vats that you can grow these bacteria in?

Dave Denkenberger: Yeah. Sorry, that might be confusing, but repurposing the —

Rob Wiblin: The infrastructure, or the —

Dave Denkenberger: — the labor and the industrial materials. Yes.

Rob Wiblin: Yeah. That makes sense. Are there any challenges with that one that we should be aware of, or uncertainties you have about it?

Dave Denkenberger: This one we came out at about $2 a day for one person’s calories. And of course then there’s the opportunity cost of that natural gas. So in the economic model, we’d have to look at how the price changes. So this is more current prices. My logic is that there’s definitely going to be some type of a global recession or depression, even if just because we’re going to spend more money on food and less money on toys. And so we’re going to spend less energy on some things, so the equilibrium price of energy might not be that much higher. But we need to work that out.

Rob Wiblin: Okay. So in order to estimate the cost here, you’ve kind of taken current prices for these inputs. And I guess that could be too low, because suddenly if we’re using lots of gas to produce food, that would push it up. On the other hand, if tons of factories are destroyed in this disaster, or we’re having a terrible pandemic and people aren’t going and making semiconductor chips and so on, then that could potentially push down the price for lots of these inputs. So it’s a bit hard to forecast how scarce gas would be. And I guess how scarce would steel be for making these vats.

Dave Denkenberger: Right. And of course the world would be colder, so you’d need more natural gas for heating. But we burn a lot of natural gas to air condition our homes as well through electricity.

Rob Wiblin: Right. Yeah, so potentially need to redivert it from some places to others.

Redirecting human-edible food away from animals [00:22:46]

Rob Wiblin: Are there any others that have come along? I guess we’re up to 50% now: you got 30% sugar, 20% protein… What’s the other half?

Dave Denkenberger: And to be clear, the 20% of our protein requirements is only about 2% of our calories.

Rob Wiblin: Ah, okay. So it’s not 20% of our calorie requirements, it’s 20% of the protein that we’d need?

Dave Denkenberger: Right.

Rob Wiblin: Got it. Okay. What else do you think should go in this portfolio?

Dave Denkenberger: One is fairly straightforward: we feed a lot of food to animals. And yet many animals, as I pointed out, can eat stuff that’s not edible to humans. So in a catastrophe, we would want to redirect that human-edible food away from animals as fast as possible. And so we’re looking at scaling up having animals eat the residues from agriculture.

Rob Wiblin: So this is like the leaves on wheat plants or something like that?

Dave Denkenberger: That’s right.

Rob Wiblin: That people can’t eat. How much energy is in all of the agricultural residues?

Dave Denkenberger: It’s quite big and a lot of people are looking at it as a source of fuel, and that’s where the cellulosic biofuels are looking at.

Rob Wiblin: Ah right, right. It seems like whenever we’ve been converting something into biofuels, we can potentially convert it into human fuel. That’s gotta be a common theme.

Dave Denkenberger: It’s similar.

Rob Wiblin: Yeah. I guess to some extent, we’re trying to plan for a world where there isn’t agriculture, or it’s going to be hard to grow the wheat to get the leaves and so on. But I guess there’s tons of that material just lying about already on farms that we could then potentially feed to cows or pigs or so on. And there’s also just trees out there, so you can get lots of leaf matter and try to feed them to animals that would then eat that.

Dave Denkenberger: That’s right. But interestingly, even in a pretty severe nuclear winter… The technical terminology here refers to how much soot or black carbon gets injected into the stratosphere: 150 teragrams or 150 million tons is a bad nuclear winter, with eight degree Celsius loss within a year. But still you have about 40% as much light coming through, so we might be able to actually grow something photosynthetically. Just moving on from the ruminants, even in places where you have a really short growing season, you might not be able to grow crops. But you might be able to grow grass, so there could be some grazing continuing.

Rob Wiblin: Interesting. Is that 40% getting through in the Northern Hemisphere or 40% globally?

Dave Denkenberger: That’s globally.

Rob Wiblin: Globally, okay. So it would be somewhat worse potentially in Europe, say, but in the tropics and Southern Hemisphere not so bad?

Dave Denkenberger: Well, that’s only really in the beginning; it does spread globally within a few months.

Rob Wiblin: I see. Okay. Interesting. So initially it’s circulating in the Northern Hemisphere, but gradually it leaks down and is a bit everywhere?

Dave Denkenberger: Right.

Rob Wiblin: Interesting. Why don’t we feed these byproducts that presumably aren’t earning much revenue right now to cows and pigs and chickens? It’s a bit odd that we’re not feeding them this thing that is kind of useless rather than feeding them food that humans could potentially eat.

Dave Denkenberger: It’s a good question. And I think part of it is that, at least in the US, there’s a subsidy for corn or maize. So that makes it more economical for the ranchers to, say… Typically you do grazing early life of the cattle and then fatten them up on maize later. And so if they didn’t have that subsidy, they probably wouldn’t be doing as much feeding them human-edible food. And I think long term, as we need to get more sustainable, we need to get more food out of the same land, I think we will move more towards utilizing these agricultural residues.

Rob Wiblin: Yeah. Interesting. Okay, so there’s possible subsidies. I suppose also just calories from corn is so cheap now that if there’s practical downsides — maybe health-related downsides, or just practical issues getting the agriculture residues — if there’s any kind of downsides, maybe the feed is so inexpensive anyway that you’ll just go with the thing that’s most straightforward and most familiar.

Dave Denkenberger: Right. The cattle would not mature as fast. And so time is money here.

Seaweed production [00:26:33]

Rob Wiblin: Right. Right, makes sense. Okay, what else can you give us an update on?

Dave Denkenberger: Well, given that we might be able to actually have some sunlight here, one thing that we didn’t get to investigate in the book, but now have since, is seaweed production. And we found that it’s very promising. There are several species of seaweed that can still grow 10% per day, even with the lower light levels in nuclear winter and lower temperatures.

Rob Wiblin: Even up to adulthood? They just keep growing at 10% a day?

Dave Denkenberger: They just keep growing. So basically you have these long lines that are floated by these buoys, and you start with little pieces of seaweed and they grow and then you just chop off the growth and then they just keep growing.

Rob Wiblin: Okay. Why does seaweed grow so fast?

Dave Denkenberger: It is amazing. And it’s only certain species, and right now they’re often limited by nutrients. So at least in the near term, we would still have those nutrients. I talked last time about the potential overturning of the ocean — that if you cool the upper layers of the ocean, they sink and bring up nutrients. So it turns out that is not as large as I thought it was going to be, so the actual production from fish is not going to go up as much as I thought. But with seaweed, it’s just much more efficient, growing it directly, than having algae grow and then feeding it to fish.

Rob Wiblin: Right, right, right. You skip a trophic level, you don’t need an extra trophic level.

Dave Denkenberger: Right.

Rob Wiblin: So the point there is that during a nuclear winter, say, if agriculture’s interfered with, the atmosphere is colder, that cools the upper layer of the sea, and then that tends to sink down, which then creates this upwelling of nutrients that are on the ocean bed. And then that basically provides fertilizer to seaweed to grow faster than it would normally, so potentially you can get seaweed growing even faster than it was before.

Dave Denkenberger: Yeah, potentially. I think what they’ve found is that what they call the “net primary productivity” — that is, how much biomass is produced per year — will still fall in a nuclear winter, but it won’t fall as much as on land because of that nutrient enrichment.

Rob Wiblin: I guess also one benefit that anything under the ocean has is that the temperature falls much less under the sea, because the water buffers the temperature change. So while you might get a lot of plants on the surface dying from frost and things like that because of the winter conditions, under the ocean the temperature might only drop a couple of degrees.

Dave Denkenberger: That’s right.

Rob Wiblin: What kind of inputs do we need in order to grow much more seaweed? I guess you’ve got to be around a coast, and then you were saying to grow seaweed, you attach it to ropes? It’s a bit like rope-grown mussels or something like that.

Dave Denkenberger: Yes. So it turns out we produce a lot of synthetic fiber for other reasons, like clothing. The main constraint here is twisting those fibers into ropes that we’re going to attach the seaweed to. We found that right now, we don’t produce that much rope — we would actually have to increase our rope-twisting capability by 300 times, which sounds kind of crazy. But it’s actually a really simple process, and people have done it in their garage with a drill, basically twisting these fibers. But these pieces of equipment are only like $10,000 and you can make a lot of rope, so it turns out it takes a very small percent of our manufacturing budget to make a lot of rope twisters.

Rob Wiblin: I mean, most seaweed is growing out of the ocean bed on rocks and things like that, right? It attaches to something on the bottom and then it grows upwards. But that’s no good for us? I guess all of that seaweed that can attach to rocks on the bottom of the coast, that’s already growing, so we need to have some artificial environment that’s very conducive to seaweed growing. And I suppose the closer it is to the surface, the more light it’s getting, so it might grow faster if we are attaching it to ropes near the top.

Dave Denkenberger: That’s right. So seaweed, why it can handle low light levels, is it often does grow 10 meters down in the ocean. But yeah, we want to have it near the surface in nuclear winter.

Rob Wiblin: Yeah. Okay. So the limiting factor is ropes that you’ll be hanging out of boats and things like that?

Dave Denkenberger: Yeah. So you’d be taking the rope and you’d be attaching small pieces of seaweed to it. Then you string the rope out in the ocean, and it’s held upward by buoys and then also anchored at the end.

Rob Wiblin: Yeah. What do we generally make these ropes out of? Is it cotton? So would repurposed stuff that was going into clothes, or…?

Dave Denkenberger: It’s actually typically synthetic materials because they’re more durable.

Rob Wiblin: I see. That makes sense. Okay. And the limiting factor is being able to spin ropes, or twisting ropes, basically.

Dave Denkenberger: Yes.

Rob Wiblin: Because if you don’t twist ropes a lot, then they break or things won’t attach to them?

Dave Denkenberger: Basically you want to transform this small-diameter fiber into something usable. And they do that by twisting or weaving the fibers together.

Rob Wiblin: Yeah. Okay. But that’s a pretty straightforward process. What fraction of food do you think we might be able to get from seaweed ultimately?

Dave Denkenberger: Not surprisingly, with that 10% growth per day, assuming we can scale up that rope twisting, we could actually get up to 160% of human calories in less than a year.

Rob Wiblin: Okay. Surely there’s some bottleneck here that would limit us. So we’ve got the rope — well, we’ve got the material, then we’ve got the spinning. Don’t we need a ton of boats or buoys in order to hang these things off of?

Dave Denkenberger: You do need boats, but we do have quite a few personal boats. And as long as you’re not very far from the shore, they could even be human-powered rowboats. If it’s farther away, of course you need to have some source of power.

Rob Wiblin: Yeah.

Dave Denkenberger: So it turns out we could do this with less than 1% of the ocean area. We don’t actually have to go very far away from shore.

Rob Wiblin: Yeah. Okay. Is there some downside to the seaweed stuff? Maybe we’ll come back to the seaweed once Sahil is with us. He could talk about it, because I guess he’s trying to make a business out of this, right?

Dave Denkenberger: Yeah. Obviously people can’t eat all seaweed, and even at the level of relatively small number of calories, there’s concern about getting too much iodine, if you look at the upper limit of iodine. However, there was an interesting natural experiment, where some Peace Corps workers thought they were taking a supplement, but they were actually taking iodine tablets that were used to purify water. So they were, for over a year, ingesting 50 times the upper limit of iodine.

Rob Wiblin: Per day.

Dave Denkenberger: Per day.

Rob Wiblin: Okay, yeah.

Dave Denkenberger: And they only had minor conditions, and they were reversible. So I think this shows that we can push it farther than normally recommended. And that could get you up to, perhaps, a quarter of your calories. Now of course, there’s the issue of whether you want to eat that much seaweed, but then again, if the alternative is starvation…

Rob Wiblin: Maybe you would, yeah. I think the only time I’ve eaten seaweed is like a salty seaweed, crushed up — they’re like chips, basically. I think they’re like a Japanese or Korean snack or something like that. Is that how we would eat the seaweed? Presumably we would eat it in some slightly less palatable, less fancy way, if this is how we were getting most of our food.

Dave Denkenberger: We might be able to do something similar. I’ll talk later about how we might be able to produce other fats that we could fry it in. But the other example is just sushi seaweed.

Rob Wiblin: Ah, right. Of course. Yeah, yeah, yeah. If you’re always going to have a meal of just seaweed, do you have any idea of what… I guess you could fry up seaweed, and then it’s kind of like eating a fried vegetable?

Dave Denkenberger: I think so.

Rob Wiblin: Yeah. Interesting. Okay. I guess I have this idea that seaweed is really chewy, but I guess once you like, I don’t know, mash it up a bunch then it’s not so bad.

Dave Denkenberger: Yeah, you might even be able to turn it into something like flour.

Rob Wiblin: Hmm. Okay. Amazing. Okay, is there anything more to say on the seaweed before we move on?

Dave Denkenberger: Well, I’d point out both with seaweed and these fermentation or single-cell protein options, I’m excited that The Good Food Institute is now working more on that as well.

Rob Wiblin: Okay. So The Good Food Institute, they’re more focused on animal wellbeing or trying to end factory farming, and come up with replacement foods for meat and eggs and so on. Yeah, how would they use these to replace meat?

Dave Denkenberger: In the case of the methane single-cell protein, it’s very high protein, so that could be used as a meat substitute. Many seaweed species are not very high in protein, but some are. So again, they could use that as a meat substitute.

Rob Wiblin: Okay, so they’re alternative protein sources potentially. Do they have any benefit over the… I guess, classic ones now are soy protein, pea protein, I think there’s some others. Maybe this is outside of your bailiwick, but do you have any idea what the benefits might be of this bacterial protein or seaweed protein?

Dave Denkenberger: I think there’s potentially sustainability benefits. These processes would not use a significant amount of fresh water, and they’re not taking away from agricultural land. And in the case of the methane: right now, if it’s already being flared because it’s in a remote location and it’s not economical to deliver to a market, then maybe we could build a factory there.

Rob Wiblin: Yeah. God, I love the idea of taking a gas field and turning it into a source of food. I just saw Dune on the weekend… It feels very sci-fi that you’re taking fossil fuels and growing something that people can eat. I think in the past, people were really focused on making meat substitutes out of soy protein or some of the others. And then people really cottoned onto the fact that pea protein has some uses for making texture that is a lot more like meat. So maybe these other sources of protein might turn out to have their culinary uses to replace different sorts of foods that people are familiar with.

Crops that can handle lower temperatures or lower light [00:35:24]

Rob Wiblin: How about the outdoor growing of plants? Like you were saying, the sun wouldn’t be completely gone in most of these scenarios. So just as we can grow seaweed, we can probably grow some crops that are more familiar with colder temperatures or lower light.

Dave Denkenberger: That’s right. So things like potatoes, canola, sugar beets, even wheat and barley.

Rob Wiblin: Okay. Just a few days ago, coincidentally, I was looking into the yield that you get of different crops per acre. And I was astonished by how productive potatoes are — the amount of calories they produce per acre in normal conditions is extremely high. Which I guess is how it ended up being one of the staple foods that supported civilizations, like highly populous big-city civilizations in the Americas. What is there to say about these crops that can tolerate low temperatures and lower light?

Dave Denkenberger: One of the concerns is that there could be high ultraviolet radiation, and the climate models indicated for a regional nuclear war — such as India, Pakistan, that might produce around a 1.5 degree Celsius temperature drop — that the ozone layer would be largely destroyed and have higher ultraviolet radiation.

Rob Wiblin: Sorry, explain that a bit more slowly. Why would the ozone layer go away?

Dave Denkenberger: So the soot or the smoke going up into the stratosphere: the sun is absorbed up in the stratosphere, and that actually warms the stratosphere and makes the destruction of ozone faster.

Rob Wiblin: Ah, it’s like churning different layers such that the ozone doesn’t get formed or is getting degraded somehow?

Dave Denkenberger: Getting degraded, I believe.

Rob Wiblin: Wow. Interesting. Okay. So we’d have issues with UVA, UVB, UVC, potentially that causes cancer or is damaging to plants?

Dave Denkenberger: Potentially, so that’s a concern for that scenario. But so far the climate modeling of the real extreme nuclear winter, it just blocks so much sunlight that it doesn’t look like there’s going to be a lot of ultraviolet radiation.

Rob Wiblin: Ah, okay. So a higher fraction of what’s getting through is UV, but you’ve also got this dampening of sunlight just in general. So it seems like on net, plants are going to be able to cope with it all right.

Dave Denkenberger: Right.

Rob Wiblin: Okay. How productive might these crops be? Normally you grow potatoes somewhat out either a bit to the north or a bit to the south of the tropics — they’re not a tropical crop I don’t think — but in this situation, would you move them closer to the equator, whether there’d be higher temperatures and more light?

Dave Denkenberger: That’s right. And actually, many areas in the tropics would even have a growing season year-round.

Rob Wiblin: Right. So is there much to say in choosing between the different ones that you mentioned? I guess potatoes are stuck in my head, but there’s also wheat, barley, oats — all of these things potentially can deal with these conditions?

Dave Denkenberger: Right, and it’s great to have a variety. Potatoes aren’t the highest protein, whereas wheat is higher. Canola is really important to produce the fats.

Rob Wiblin: Yeah.

Dave Denkenberger: But these are the ones we’ve chosen that we think would work well and are lower cost. There are many other cool-tolerant species that are higher cost that we would grow as well, like carrots and other vegetables, but we’re focusing on the lower-cost ones.

Rob Wiblin: Okay. Makes sense. So if we’re moving them to more tropical regions where you weren’t typically growing these crops before, is it going to be very hard for people to learn how to completely switch what they’re growing? I’m imagining, if we’re going to be stuck growing potatoes in Thailand, farmers there might not have a lot of familiarity with these crops. They might have to redesign, rejig how they’re doing things.

Dave Denkenberger: That’s right. So there definitely would need to be international cooperation here, both to move the seeds to the tropics, but then also the training, the knowledge. So it’s a big advantage to get the right crops in the tropics. But the other thing is that if we’re not growing food outside the tropics (or not nearly as much), we can use the inputs we have and focus them on the tropics — things like fertilizers, pesticides, tractors. So that’s the other reason that I think we can do a lot better than just crops where they’re currently planted with the current inputs.

Rob Wiblin: So what fraction of global calories do you think we’re bound to get through the outdoor growing that we can still do? And I guess greenhouses as well?

Dave Denkenberger: In particular with outdoor growing, it’s very preliminary at this point. We’re looking at using the climate model outputs from nuclear winter and crop growth models. But we think in the ballpark of half of human need. But that doesn’t mean that we’d produce half as much food as we do now, because right now we produce two or even three times as much food as we need. So it’s still a big reduction in overall output.

Rob Wiblin: Okay, and that extra stuff is going to biofuels and feeding animals and so on.

Dave Denkenberger: Right.

Rob Wiblin: But we’ll be able to produce half of the theoretical number of calories that humans need to not be starving.

Dave Denkenberger: Right, and this is actually an example of where I was more pessimistic in the book. So yeah, I think in some cases more pessimistic, some cases more optimistic — but overall, it’s looking like a similar picture.

Rob Wiblin: Okay, interesting. Yeah, what was the update that made this seem more valuable than you thought a few years ago?

Dave Denkenberger: Well, I was concerned about the relocation of crops, whether they would be highly dependent on particular soil types — that doesn’t seem to be as much of a problem. I was concerned about UV initially, and I was also concerned about the temperature swing and freezing — but it turns out that it’s not as much of a problem.

Rob Wiblin: How confident can we be about that kind of climatic modeling? I guess we’ve got issues with: Would we get frost? How much would the temperature change? Would the UV be like this? Is this all highly uncertain, or do we have a reasonable idea?

Dave Denkenberger: I think the regional results of climate models are getting more reliable, but there is definitely uncertainty.

Rob Wiblin: Yeah. So we wouldn’t want to completely bank on this, but the central case seems like agriculture in some places is still going to be pretty viable, if we choose the right crops.

Greenhouses [00:40:51]

Rob Wiblin: I remember you talking about potentially making greenhouses, which seems like a great idea, because I think we can grow all kinds of stuff in quite northern latitudes using greenhouses now. It seems like it’s going to be a similar situation in a nuclear winter situation.

Dave Denkenberger: That’s right. So at first I didn’t think we would be able to cover much area. It turns out that we make a lot of polymer, but we don’t extrude a lot of polymer sheet. So the bottleneck there is to make a lot of these extruders that make the clear polymer sheet.

Rob Wiblin: Okay. So greenhouses aren’t made out of glass now? They’re mostly made out of this plastic polymer?

Dave Denkenberger: Yeah, typically. What we’re looking at is a very low-tech greenhouse that we can scale fast, so we’re just looking at a thin polymer sheet.

Rob Wiblin: Okay, yeah. And you thought that we wouldn’t be able to produce as much of it, but it seems like maybe we could?

Dave Denkenberger: It turns out the actual extruders are not that expensive. So, again, if we can use some of our manufacturing construction budget, we can make a lot of these extruders and cover a lot of area.

Rob Wiblin: Amazing. I suppose you need steel bars and other things in order to produce these quickly?

Dave Denkenberger: Or just wood framing.

Rob Wiblin: Oh, right.

Dave Denkenberger: And nails. We looked at current wood production and nails, and the main constraint was the plastic cover.

Rob Wiblin: Okay. So you can do a bit of an IKEA job with this, where if you have a bunch of these clear-ish plastic sheets and then you get a bunch of wood, you can nail them together and make a makeshift greenhouse that’s good enough for growing stuff.

Dave Denkenberger: That’s right. We’re not talking about any heating or air conditioning, but still, you can raise the temperature significantly, such that these more tropical crops might be able to grow — so corn, rice, soybeans.

Rob Wiblin: So is this five or 10 degrees higher than the surrounding area?

Dave Denkenberger: Around that.

Rob Wiblin: And I guess more stable; it would buffer the day and night temperature shift. Any speculation on what fraction of our calories we’d be able to get using this method?

Dave Denkenberger: We’re getting around a fifth of our calories by the end of the year.

Rob Wiblin: I suppose we’ve got several different ways in which we’re trying to redirect the talent and the industrial base. We’ve got this use for plastic, we’ve got rope spinning, we’re potentially redirecting people to working in these paper mills making food. Do any of these compete with one another in terms of the inputs that they need?

Dave Denkenberger: The ones that really compete would be the sugar and the methane production, because that requires a lot of capital.

Rob Wiblin: I see.

Dave Denkenberger: So we could definitely cover the greenhouses and the rope twisting for seaweed no problem.

Rob Wiblin: Yeah. We currently produce a ton of plastic for all kinds of uses, right? And so we’re basically going to repurpose the inputs that we were using for other plastic goods into making these kinds of sheets. And it turns out that the amount of sheets you need, in terms of just the total global plastic output, isn’t so high?

Dave Denkenberger: That’s right. So, again, in the eventual economic model, we’ll need to take into account that opportunity cost. But at this point, we estimate that it might add around a dollar a day for a person because of the cost of the greenhouse. So if we look at the cost of rice, we might add another dollar a day, so you might be up to $2 a day or something like that.

How much to trust this economic modeling [00:43:50]

Rob Wiblin: Okay. So we’ve talked about quite a few different options here, and some of them seem remarkably promising. You’re talking about doing economic modeling of envisaging the economy as a whole, rediverted towards doing all these things at once. I would’ve had the intuition that it’s extremely hard to model that kind of thing, or at least the tools that economists have for envisaging how policy would change this or that might not transfer super well to envisaging such a different world. How much faith should we have in this modeling and how do we even go about it?

Dave Denkenberger: It is definitely a concern. And at this point we’ve really only gotten to a relatively simple model where we can say, “Well, we only have one industrial construction budget” — so right now we’re actually just putting in the sugar and not the methane single-cell protein, because they do compete.

Dave Denkenberger: So in what we call the integrated model, we’re looking at the lowest-cost, most promising resilient foods, but we also will have fortunately some stored food that we can use initially. And there would be some amount of animals that we would slaughter soon and preserve, but then we don’t have to eat them right away. So we can look at when that’s optimal to meet calories, protein, and fat.

Rob Wiblin: Yeah. Okay, so we’ve got this initial period where we have some stored food, we have food that’s out in the fields. What stuff could we do really urgently in order to try to feed people, you know, in month three — when we’re running out of the stored food, but maybe some of these other ideas haven’t really come online properly yet.

Dave Denkenberger: One of them is that we do expect some amount of harvest of food that has already been planted, because the climate change does take about a year to take effect.

Rob Wiblin: Oh, interesting. So in a nuclear winter scenario, it’s not suddenly from one day to the next it’s incredibly cold. It’s a more gradual shift over a year.

Dave Denkenberger: Right. It does happen pretty fast in the center of continents, but then the ocean cools more slowly.

Rob Wiblin: And I guess maybe you have an issue where, as you were saying initially, the soot is more concentrated in the areas where the nuclear war was, and so other areas it takes a while for the temperature to drop.

Dave Denkenberger: Right.

Rob Wiblin: Interesting. Okay. So we could have a reasonable amount of lag time during which we can react — at least if you’re near coasts, I suppose, or you’re near places where food is already stored rather. I guess not the UK — do you know off the top of your head how much food storage we have in the UK? I think it’s shockingly little.

Dave Denkenberger: I think it’s very little intentional storage, but I think there would be a significant amount of on-farm storage, just because you’re growing wheat.

Rob Wiblin: Yeah. Interesting.

Dave Denkenberger: So at this point we have this graph of a summary, and we haven’t fully incorporated the fact that if we do a good job and produce a lot of resilient foods, that means the price of food is not that high. Some amount of food probably still would go to animals, but then that means we need to produce even more food. So we’re still working that out. We do think that biofuels should be turned off, because the price of food is going to go up more than the price of energy, we’re pretty sure. But one of the policy suggestions, of course, is to have governments agree ahead of time to turn off that biofuel production.

Rob Wiblin: Biofuels… I can put up some links to articles about this. It seems like biofuels can make sense if you’re doing sugar cane — potentially they’re actually producing a net amount of energy. But my understanding is with things like corn biofuels, in fact, you use more fossil fuels making the corn than you get fossil fuels out of the corn for ethanol production. Have you looked into this issue or heard of this?

Dave Denkenberger: I’ve looked into it a little and yeah, that could very well be true.

Rob Wiblin: Okay. Yeah. So the corn stuff already seems a bit crazy. Although I suppose a funny thing about this corn ethanol production is that it means that the fact that we’re squandering so much corn for no reason means that we have this excess ability to produce food that is currently just going to power cars, and that could potentially be quickly repurposed if we have the intelligence to stop making the biofuels if there’s a famine.

Dave Denkenberger: That’s right. So it does actually make us more resilient.

Rob Wiblin: Yeah. Interesting. Yeah. Is there much more to say on this integrated model?

Dave Denkenberger: The preliminary conclusion is that, looking at the lower-cost resilient foods, it looks like we can produce more than actual human need. So there would be some leeway for some other uses. Then what we’re trying to work out is… We know the cost of production, but the price means the equilibrium between demand and supply. So we think it’s still going to be in the ballpark for the vast majority of people to be able to afford it.

Rob Wiblin: Okay. I see. So I suppose one angle on this is looking at how many total calories are we producing, and is there enough protein and fat in the mix? The other angle would be just looking at what would be the equilibrium food price, and then think, “Well, could people who are poor afford food in this situation?” — which I suppose is the relevant one if you’re thinking about it, that we’re still having food markets, and food is still being rationed through prices and your ability to afford it.

Rob Wiblin: I guess just thinking about it in terms of food output might be the way to think about it if you expect total food rationing — the way, say, the UK had during World War II, where they were like, “Well, we’ve got this many calories and we’re just going to split it between everyone. It doesn’t matter how rich you are. You can’t buy more food, even if you want to.”

Dave Denkenberger: Right. But say in a poor country, even if you redistribute people’s wealth, they still might not be able to afford it if it were expensive on the world market. But potentially you could have international charity for that.

Rob Wiblin: Yeah. Interesting. So I suppose it’s a lot easier for a single country to ration food. Countries tend to have this welfare system, like, redistribution process internally, but then they don’t tend to be as generous to foreigners. So you’d have the major problem in poorer countries, where who’s going to be sending them the food? Who’s going to be denying their own people lots of food in order to send it overseas? I suppose you’d get a bit of that, but you might not expect to be able to feed billions of people that way.

Dave Denkenberger: But fortunately, many of the less-developed countries are in the tropics. So they do have potential to grow food.

Rob Wiblin: The charity might be running the other way potentially. So, okay. You’ve got some economists who are developing these general equilibrium models, looking at how the prices of different goods would shift and what might the price of food end up being under these different scenarios. So that’s one way of envisaging this.

Rob Wiblin: Another way might be to try to bring some engineering common sense to it, perhaps thinking, “Do we really have enough skilled people to scale up all of the rope production? What would be the bottlenecks there? In the past, when we’ve tried to do massive repurposing, how has this gone in general? Has it gone as quickly as people expected it to?” Do you do any sort of analysis of that style as well, maybe thinking about what could go wrong and how likely is it to go wrong?

Dave Denkenberger: One of the things we really want to do is actual pilots of this to demonstrate that we can scale it up quickly.

Rob Wiblin: Okay, so rather than speculate, actually to see if we get a bunch of people to try to do this, how quickly can they pull it off and what roadblocks did they face in getting there?

Dave Denkenberger: Right.

Rob Wiblin: Yeah. I guess you seemed pretty optimistic a couple of years ago, but it was very early days and a lot of these things you hadn’t investigated as much as you have now. It seems like the picture is unbelievably positive, if I’m reading this right. Just the amount of different options we have for producing tons of calories is remarkable, given that you might expect that this idea of feeding everyone for a nuclear winter might be a bit of a pie-in-the-sky dream that we’d never really accomplish, and maybe we’ll just be trying to get a billion people through. It seems like feeding everyone no matter what is actually a viable vision.

Dave Denkenberger: Potentially. One concern is the nutrition. But now that we can talk about some outdoor growing and some greenhouses, we have a separate paper on nutrition that should be out pretty soon. There are some deficiencies, but then there are potentially ways around them. If it’s vitamin D, you might be able to go outside.

Rob Wiblin: Yeah. Okay. There’s going to be lots of UV, I hear. Or a similar amount of UV to before potentially.

Global cooperation [00:51:16]

Dave Denkenberger: Certainly a concern here is that our initial modeling is assuming global cooperation. The UK has a lot of potato seed, and they wouldn’t be able to grow them themselves — would they actually trust another country to grow the potatoes and then give them back more food than originally? So ideally we could actually talk about some of these agreements ahead of time so that people could be pre-committed to it.

Rob Wiblin: I see.

Dave Denkenberger: But certainly we are concerned about cooperation breaking down. We’re going to be moving into more regional geographic information systems (or GIS) analysis, looking at the resources of individual countries from a resilient food perspective, and then actually working out what would happen if international trade turned off — it would be much worse. What we’re hoping to do is use that information to convince governments to actually cooperate.

Rob Wiblin: Interesting. Okay. So most of this modeling, and I guess some of this optimism, is driven by a picture where most industry is still around, people are still trading, there’s still lots of ships. People are still chatting online — they’re able to send seeds here and there and send information about how to grow potatoes to Thailand and whatnot.

Rob Wiblin: But if we envisage a world where, I guess economists call it autarkic — where each country has to fend for themselves or each region has to fend for themselves — then things get a lot trickier, because it’s so much harder to bring together all of the components to really nail any one of these food suppliers.

Rob Wiblin: And I guess you don’t just want one, because then you’re just only having carbohydrates and no nutrients and so on. So there’s a whole lot of ways in which that situation is way worse. And that’s part of why you want to explain this to people ahead of time and get them to figure out how they’re not going to end up in that situation.

Dave Denkenberger: That’s right. In the past — say 2007, 2008 — the actual food production shortfall was less than 1%. But because of countries doing export bans, rice price went up three or even four times. So it’s a major risk, restriction of trade. There’s even potential of restricting more than just food trade, if we lose that trust and cooperation. And that would be just catastrophic, because then you lose energy trade and minerals and components — and the supply-chain issues we’ve seen in COVID are nothing compared to that.

Rob Wiblin: Right. I guess we’re considering a bunch of different scenarios here. I suppose with a volcano, probably almost no infrastructure is destroyed, all the ships are still running. In the nuclear war case, a whole bunch of stuff is destroyed, but still a remarkable fraction is still online. I guess you have to model these quite differently if you’re trying to figure out the threat to international cooperation in each instance.

Dave Denkenberger: I think in the case of a supervolcanic eruption, you could certainly have continent-scale destruction of infrastructure.

Rob Wiblin: Oh, interesting.

Dave Denkenberger: Similar with an asteroid impact — a similar order of magnitude, I would say. However, there are important differences. One reason why nuclear winter is significantly worse is because it’s black particles going into the stratosphere, and those absorb the sun and then they’re lifted higher, so they can stay for a decade. Whereas with the volcano, it’s sulfate — more whiter particles — and they fall out faster. But then also if you have a nuclear war —

Rob Wiblin: Someone’s been annoyed with someone else. There might be some preexisting tension.

Dave Denkenberger: Yeah. Of course it could be accidental, but still there’s an enemy involved, and so cooperation would be even more challenging.

Rob Wiblin: Do you have an intuition for if there was a supervolcano eruption, whether humanity would mostly pull together? I don’t know. I suppose we’re going to talk about COVID-19 in a minute, but my sense was cooperation during COVID-19 was pretty good, and it could be even better during a volcano situation.

Dave Denkenberger: Potentially. I’m very concerned that if people don’t know about resilient foods —

Rob Wiblin: They could panic.

Dave Denkenberger: — then they could conclude that most people are going to die. It could be an incentive for countries to do very bad things, like steal food from your neighboring countries. So I am very worried about that, and that’s why I want to get the message out that we could actually feed everyone if we cooperate.

Rob Wiblin: Yeah. That was a big part of your vision of how you would have an impact in the first interview, that some low-hanging fruit was just getting people to be aware that there’s so much stuff that they could do that isn’t going to war and stealing food — that they should be extruding plastics to build greenhouses; that’s actually a much better option. Is that still a big part of the vision for how ALLFED can ultimately make things better?

Dave Denkenberger: Yeah. That’s a big part of the vision.

Rob Wiblin: Yeah. I suppose you’ve already been spreading that a little bit, but maybe it’s more persuasive when you can bring more and more engineering details to bear, so that people are actually properly persuaded that all of these things are viable.

Dave Denkenberger: Yes. And this country-by-country analysis: if we can know roughly what each country has in terms of resources, we could actually give them a draft plan. Now of course they’ll say it’s wrong because of this reason, and you don’t know this classified information — but we’re kind of jump starting them, and then hopefully they would actually have a viable plan to respond quickly.

Rob Wiblin: Yeah. We’ve talked about a lot of individual foods and about how some of them are more protein heavy, some more carbohydrate heavy, some might have some nutrients. Have you been able to think yet about what is the optimal combination of these different things to meet people’s nutritional needs, and I guess possibly even not be that disgusting to eat?

Dave Denkenberger: Yeah. You could certainly make a very well-balanced appetizing diet. However, my concern is that the poor of the world may have limited options. So I’m particularly interested in putting together a diet of these lower-cost foods, perhaps also some processing. We make juice, there’s pulp leftover. It’s typically fed to animals, but people could eat that — it’s very nutritious. So we could make better use of residues as human food, and that could be low cost.

Rob Wiblin: Yeah. This is maybe a random question, but do most countries produce their own paper? Is paper a local production thing? Because it would be great if one of the key inputs that we need is spread out all over the place so that people can turn wood into food in each given city.

Dave Denkenberger: My understanding is that paper production is quite distributed, because the actual wood going into it is not that expensive, so you can’t afford to ship it too far. So yeah, I think that’s a good one for many countries.

Rob Wiblin: Okay. So in most places where they have timber, there’s going to be paper production somewhere nearby, and that’s pretty all over the place.

Dave Denkenberger: Right.

People feeding themselves using these methods [00:57:15]

Rob Wiblin: So in terms of figuring out what are going to be the bottlenecks, what are going to be the biggest challenges, and also just being able to persuade as many people as possible that this broad approach is viable and will be able to feed most people… It seems like it would be really cool to have a group of people who, say, go somewhere where the sun is very weak, try to eschew all other foods — don’t buy foods, and instead try to use these methods to produce enough food for themselves while just buying the kinds of inputs that you expect might be available in these sorts of scenarios.

Rob Wiblin: Do you think that it would be possible for you and maybe a team of other engineers to, I don’t know, go somewhere not that hospitable in Canada and produce enough food to feed yourself using these sorts of methods?

Dave Denkenberger: What we’ve been focusing on is the lower-cost options, so it’s going to be lower cost to turn fiber into sugar at the industrial scale. However, it would be an interesting proof of concept and potentially relevant in very severe catastrophes if cooperation broke down and we can’t build factories or repurpose factories.

Dave Denkenberger: The solutions are going to be different though. Some things that could be done at small scale are mushrooms — maybe some people have a lot of leaves or wood chips or something in their backyard, and they could grow mushrooms on them. Rabbits can be done at small scale — they can digest cellulose. There is some work on whether we could turn cellulose into sugar at small scale, but we’d have to figure out the enzyme issue.

Rob Wiblin: Okay. Yeah. I guess I wrote this question before I’d thought about all of this, but let me think about it. So I suppose it seems like you could plausibly try to do the big rapid scaling up of seaweed if you went somewhere on the coast and were like, “How much can we feed ourselves without high-tech stuff, just trying to grow lots of seaweed quickly?” I guess the greenhouse is a good one for seeing, can people who don’t have a lot of skill with greenhouses buy some plastic sheeting and grow food that way relatively quickly?

Rob Wiblin: The ones that aren’t super suited to going out and just grabbing a bunch of people and trying it out is the paper mill reconstruction — you’d have to, I guess, talk to your paper mill and rent out the paper mill or something and retool it a bunch — and the methane production from gas, that’s also maybe quite capital intensive. So we’re talking raising millions of dollars and actually having a proper team try to build that.

Rob Wiblin: Maybe you could try seeing how hard it is to teach farmers in a tropical area to grow potatoes? That’s something that could be tried on a small level by someone who’s willing to spend a year — if they could pay people to spend the time, take the time away from their normal agriculture into growing a crop that normally they wouldn’t.

Dave Denkenberger: Yeah. We’re definitely interested in these demonstrations, but I guess I thought you were asking what would work for a typical household. So if you’re not in the tropics, then you can’t do a greenhouse. If you’re not by the coast, you can’t do seaweed. So you’re much more limited.

Rob Wiblin: Yeah. What sorts of trials would you like to get to first? It sounds like maybe the cellulose to sugar one is particularly promising to give a go.

Dave Denkenberger: Yeah, we’re really interested. There are some paper factories that are becoming idle. We’re using less of what’s called kraft paper, the white paper. We’re still producing a lot of cardboard for Amazon boxes.

Rob Wiblin: God, you should see sometimes what it looks like near the door to my house. I don’t even know how the waste system is dealing with the extraordinary amount of cardboard that I see coming out of my apartment building.

Dave Denkenberger: It’s actually a project up in Alaska, in these remote communities where they still get Amazon free shipping. So they’re looking at the cardboard as an energy source.

Rob Wiblin: Oh wow. Right. That makes sense.

Dave Denkenberger: So if there’s a paper factory that’s going to be going out of business anyway because the demand for its product is going down, then that could be a great opportunity to do an actual example pilot of repurposing.

Rob Wiblin: Yeah. That sounds great. Are there already businesses doing the methane to bacteria?

Dave Denkenberger: Yeah, there are a couple companies. They’re focusing on fish food at this point, but they’re also interested in making meat substitutes.

Rob Wiblin: Yeah. Interesting. Do you know any of the names of those businesses off the top of your head?

Dave Denkenberger: Yeah. The methane ones would be Unibio and Calysta.

Rob Wiblin: Okay, cool. Yeah. We’ll stick up links to their home pages. For some of these, it seems like survivalists — who are serious about making it through lots of pretty grim situations — could be extremely interested in the kind of methods that you are talking about here, at least I suppose the greenhouses, potatoes, that kind of thing. Is there any potential revenue stream or maybe a way of getting these materials and knowledge out there, selling it to the kinds of people who for idiosyncratic reasons are very interested in these approaches?

Dave Denkenberger: Potentially. But again, if our goal is to try to feed everyone, we want to focus on these large-scale solutions that would be lower cost.

Rob Wiblin: Yeah. Interesting. Okay, so the basic picture is ALLFED has limited resources, and the main thing you want to focus on is industrial scale. We want to feed billions of people. We can’t do this by just getting amateurs to go out into the forest and try to feed themselves. We need a properly modern approach to feeding people through a nuclear winter.

Dave Denkenberger: That’s right.

Rob Wiblin: Have you gotten any interest then from governments or military or security folks who spend more time thinking about how does the country get through a disaster? They seem like they might have the resources or the kinds of analytic capacity to think about this on a larger scale than ALLFED can.

Dave Denkenberger: Yeah. We’ve definitely been talking to some governments. One issue is that for localized disasters, the cheapest thing is just to ship food in.

Rob Wiblin: Oh, okay.

Dave Denkenberger: But there are scenarios where you might not be able to do that, and it could be valuable to have some local production of food. One example is if you have a crop failure — that means you don’t get any human-edible food, but you’d still have leaves on the crop. So if you could take those leaves, grind them up, get that juice, boil it, and you get a protein concentrate on the top. That could be a good supplement.

Rob Wiblin: Okay. Interesting. So that’s the kind of thing that could be useful if you had crop failure and you also couldn’t import lots of food.

Dave Denkenberger: Yeah. A hurricane maybe.

Rob Wiblin: Hurricane. Oh, interesting. Okay. I thought that there’s some countries that have serious food security issues. Japan stands out as a country that imports a ton of the food that it eats and would be in trouble if for some reason trade got cut off, in a war or otherwise. Maybe it’s difficult for your team to liaise with the Japanese government or the Japanese military — language barriers among others — but I wonder whether there could be countries that might be interested in thinking about this more seriously, because they perceive food security and trade cutoff as one of the primary threats to their nation.

Dave Denkenberger: Yeah, definitely. So they don’t even necessarily have to believe in global catastrophic risk to be worried about trade being cut off. Other examples could be Singapore, and countries in the Middle East.

Rob Wiblin: South Korea possibly.

Dave Denkenberger: Yeah.

Rob Wiblin: I guess the UK actually.

Dave Denkenberger: Yeah. And that’s another example — like with the UK, with your port disruptions. So again, it doesn’t have to be a global catastrophic risk here. If your ports were cut off for a certain number of months, you’d run out of food.

Rob Wiblin: Yeah. Just on that, I’ll link to an article that points out that it’s astonishing how much the UK has managed to sabotage itself. A major issue is that after Brexit, the rules were changed about internal trucking within the UK, such that when truckers drive in with imports from the EU, they’re not allowed to transport food between different places within the UK. I think they call it cabotage — it’s basically a protectionist measure to protect the trucking industry within the UK. But it means that there’s tons of trucks now driving through the UK empty because they’re not legally permitted — because they’re registered in another country — to transport goods within the United Kingdom.

Rob Wiblin: This is apparently like a major contributor to the supply disruptions that the UK is having. For those who aren’t here, there’s a lot of empty supermarket shelves at the moment and a remarkable amount of stuff out of stock. To find out that this is mostly because of regulations that we’re imposing on ourselves annoyed me a little bit. But yeah, it speaks to the fact that this can happen without necessarily having an external disaster that messes you over.

NASA and ALLFED [01:04:47]

Rob Wiblin: I know something you’ve been working on the last few years is thinking about how you might feed astronauts on things like the International Space Station, or ultimately one day on Mars. I think you got a grant from NASA to look into this stuff, right? Tell the audience about that, it sounds pretty fun.

Dave Denkenberger: That’s right, yeah. Actually three mini-grants from NASA. The idea was that there were three different types of foods that we were proposing. We proposed to do both a paper for applications in space and then also for applications on Earth in catastrophes.

Dave Denkenberger: The first one was hydrogen-consuming microbes. So again, the single-cell protein idea, and there are actually several companies working on this now — Avecom, NovoNutrients, and Solar Foods. Basically you’d need electricity — which could come from solar energy or wherever — and you do electrolysis, which means splitting water into hydrogen and oxygen. Then the microbes consume the hydrogen and also carbon dioxide, and you get a high-protein product. You could also produce the hydrogen by gasifying a solid fuel, like biomass.

Rob Wiblin: Okay, so there’s hydrogen-eating bacteria, so they can eat H2 — I suppose we could speculate that these are from geothermal vents or something that emit hydrogen, among other things. You could potentially basically grow these in vats, by bubbling hydrogen up through the vats. And they’re not poisonous to humans; they’re reasonable human food. I guess you can get the hydrogen from solar panels or indeed from any energy source, because you get hydrogen by running electricity through water or something like that, right?

Dave Denkenberger: Right.

Rob Wiblin: Okay. So this is a way that we could potentially just convert any electricity that we can make into human food. Do you know how nutritious these bacteria are that come up?

Dave Denkenberger: Again, they’re very high in protein.

Rob Wiblin: Okay, yeah. I guess they don’t have all of the vitamins and minerals, but that potentially you could just carry with you because it’s so much smaller in volume. Is that something that we should have in mind for feeding people on Earth as well? Or is it so expensive that you’d really only do it if you’re in space?

Dave Denkenberger: Well, it’s a little more expensive than some of the things we’ve been talking about. Our estimate was about $3 a day for all the calories for a person. It could make sense, especially if you have low-cost electricity.

Rob Wiblin: I guess some people might be thinking, “Why don’t we just take the electricity and then use LEDs to make light, and then have the plants grow in the light?” But people might recall from our first interview that photosynthesis is an extraordinarily inefficient way of converting energy into human food. You lose something like 98% of the energy I think, because chlorophyll just isn’t a very good way of absorbing energy from electromagnetic radiation. Is that right?

Dave Denkenberger: That’s right, yeah. So it would be something like 10 times as much energy to get the same amount of food out as the hydrogen technique.

Rob Wiblin: So there’s some inefficiency in converting the electricity into hydrogen and then inefficiency in converting it into bacteria, but it’s still vastly more efficient than photosynthesis.

Dave Denkenberger: Right.

Rob Wiblin: Okay, is there much more to say about this approach? Is this something that you could see people actually building factories to do anytime soon?

Dave Denkenberger: Yeah. I mean, definitely the companies think so. Again, they’re looking at a meat substitute.

Rob Wiblin: Okay, so this is an alternative way of making protein basically, that then could be put towards all kinds of protein-y activities?

Dave Denkenberger: Right.

Rob Wiblin: Did any other things come of the NASA grants?

Dave Denkenberger: Yeah, so the next one, we focused on an even more bizarre type of microbe that actually uses electricity as an energy source.

Rob Wiblin: Okay, what? I hesitate to ask, but do you know how that evolved? Where was there electricity in the environment for bacteria to grow?

Dave Denkenberger: It is pretty bizarre, but bacteria are very flexible organisms.

Rob Wiblin: I see. Okay, cool, cool. So hold on, you put electricity through water and then the bacteria can grow from that electricity?

Dave Denkenberger: Yeah, and then you still need to provide the carbon dioxide and the other nutrients that the microbes need to grow.

Rob Wiblin: So electricity is replacing light in this scenario?

Dave Denkenberger: Yeah. Or hydrogen in the case of hydrogen microbes.

Rob Wiblin: Yeah, okay. Go on.

Dave Denkenberger: So it may be possible to eat them directly, but what we explored was actually using microbes to make vinegar or acetic acid. Obviously we wouldn’t be eating that much of it, but it would provide some diversification from the hydrogen single-cell protein if we were trying to make an efficient space food diet.

Rob Wiblin: Yeah. Well, I wouldn’t want to be in space without vinegar. What’s the reason why eating the acetic acid is better? I suppose it’s because you’re not destroying the bacteria in the process? You’re taking away this acid that they’re releasing, which has energy in it, and then the bacteria are still there to keep producing it?

Dave Denkenberger: Yeah, an easy way to think about it is it’s more efficient to make milk than meat.

Rob Wiblin: Yeah, okay. Similar situation. Okay, cool. Is there anything else or should we talk more about the electricity-eating bacteria?

Dave Denkenberger: Well, this could potentially be applied on Earth as well, but we found it was more expensive than other alternatives, so it’s not as promising.

Rob Wiblin: Yeah. People have done this, so this isn’t a hypothetical thing? People have grown these bacteria, made them to produce acetic acid?

Dave Denkenberger: That’s right, yeah.

Rob Wiblin: All right, yeah. Any other options for space food?

Dave Denkenberger: Yeah. The last one is direct chemical synthesis of food, so that’s not using a biological organism. Again, you would typically start by splitting water to make hydrogen, but then you chemically convert that into edible food. And that could be sugars or it could be glycerol, otherwise known as glycerin.

Rob Wiblin: I guess that would require a bunch of different enzymes, or a bunch of different chemical operations?

Dave Denkenberger: It’s actually chemical operations, so you don’t need a biological enzyme.

Rob Wiblin: Right. Is this hard to do?

Dave Denkenberger: Well again, it’s more expensive than some of these other food sources. But again, then you have a carbohydrate, so it’ll help with that diet diversity. And then, like you said, these three foods are not going to be enough in terms of vitamins. So you’d carry some supplements, but that’s much less weight than carrying the food, which is what they do now. They launch the food at $10,000 for half a kilogram.

Rob Wiblin: $10,000 per half a kilogram. That’s incredible.

Dave Denkenberger: Roughly.

Rob Wiblin: Oh, is that pre or post SpaceX doing their —

Dave Denkenberger: That’s NASA, so yeah.

Rob Wiblin: That’s NASA, okay. So inefficient. Cool.

Rob Wiblin: What about converting fossil fuels that are very energy dense, and trying to convert them into something that people can eat?

Dave Denkenberger: Right, so this idea of chemical synthesis, even though we could start with CO2, that’s going to be pretty expensive. So on Earth, a more cost-effective way is actually looking at parts of fossil fuels. There’s precedent here that Germans in World War II actually produced some edible fat — or “coal butter,” as they called it — from coal. At this point, we think it’s more promising to use a petroleum byproduct — petroleum wax — and turn that into an edible fat.

Rob Wiblin: Yeah. Is that difficult or dangerous or anything?

Dave Denkenberger: We already have these petroleum-based lip balms. And if you accidentally swallow a little bit, it’s okay. This particular process hasn’t been done, so this is at an earlier stage, but our preliminary estimate is that it could be pretty cost effective.

Rob Wiblin: Okay. So you have to change the structure of the lipid to a kind of fat that humans are used to eating and can digest? So it’s a bit of organic chemistry going on and you’d have to figure out how to do this on a pretty big scale, while keeping it safe enough to be edible? That’s the basic story?

Dave Denkenberger: That’s right, and our preliminary estimate was to get all the calories for a day was about $2. But the main value is that it’s fat, because many of these other resilient foods don’t have very much fat in them. So by the end of the first year, we think this could be scaled up to about half the global requirements for fat.

Rob Wiblin: Yeah, interesting. I’ve never heard of people… Well, I guess we’ve talked about this World War II case, but it seems like we never normally convert our fossil fuels into food. Again, is that just a cost issue, that there’s no particular reason to do it right now?

Dave Denkenberger: You could say normal agriculture kind of converts fossil fuel.

Rob Wiblin: I suppose you’re right, yeah. Not through direct chemistry, I guess.

Dave Denkenberger: Correct.

Rob Wiblin: Is there any potential to use space industries’ need to feed people in space as kind of a stepping stone for funding research and development into these different methods that then could be used for these resilient foods on Earth? Or is the space industry just so small that this wouldn’t be a big enough industry to really bootstrap any of these approaches?

Dave Denkenberger: I think there’s potential overlap. It is at a quite different scale. I would say that one potential overlap with global catastrophic risk would be the really extreme scenarios where potentially everyone has been killed, that you can think of, “Can we make a refuge with 1,000 people that might be able to repopulate the Earth?” And Elon Musk is interested in doing this on Mars, so if we could figure out how to make an independent colony on Mars with fewer people, and with less expensive, less infrastructure-intensive food production, then I think that could have some existential risk benefits.

Rob Wiblin: Yeah. I guess another option is doing that somewhere really remote on Earth, like under the sea, or in Antarctica or so on — where you’d also have to figure out how to feed people in a worst-case scenario. It sounds like you could potentially use a nuclear reactor to grow bacteria and then eat them — or otherwise just have stores of fossil fuels, or put it somewhere where you have access to fossil fuels — and then you could in theory eat that.

Dave Denkenberger: Yeah, that’s right. So again, if you look at the plans for having an underground bunker — typically nuclear — the plans were to go through regular plants and that’s really inefficient, so we could lower the cost of this significantly.

Rob Wiblin: Yeah, so it was either you have this enormous initial cost of stockpiling all the food and making it big enough to store food to feed everyone for ages, or you’ve got this horrifically inefficient process of converting electricity into human-edible food that now we can do 10x better on.

Dave Denkenberger: And the other thing if you use the stored food is that you’re breathing out carbon dioxide and you need oxygen. Whereas if you have a system that actually grows food — either plants, which is of course inefficient, but these space-based resilient foods if you want to call them that — they can act as the life support system, because they would actually take the carbon dioxide from the astronauts to make the food and then they produce oxygen.

Dave Denkenberger: I guess another extreme scenario is a runaway climate change scenario, where it might get too hot for plants to live. So that’s another scenario where having these type of, quote, space foods, could be a good food source.

Rob Wiblin: Interesting. God, it could be a very bizarre future, I suppose. Mostly just eating bacteria grown in electricity. Again, it sounds like absolutely bizarre sci-fi stuff. I kind of can’t believe that it actually works, but sounds like in principle it could.

Kinds of catastrophes [01:15:16]

Rob Wiblin: Okay, let’s push on and talk less about the food specifically and more about the kinds of catastrophes that could lead us to want resilient foods. Last time we spoke, you mostly were talking about nuclear winter, with a side dish of asteroids and volcanoes, and maybe superweeds, and things like that. Have you learned anything new about the relative magnitude or the relative probability of different reasons why we might end up wanting to use these resilient foods?

Dave Denkenberger: I think there’s another whole class of catastrophes that could disrupt electricity or infrastructure, and one of them would be solar storms. Another is a detonation of a nuclear weapon at high altitude, causing an electromagnetic pulse, which could destroy electronics. Another one would be a coordinated cyber attack, perhaps enabled by narrow AI. A fourth one would actually be an extreme pandemic, where people are too scared to show up to work at critical industries like electric power plants.

Rob Wiblin: Yeah, yeah. Do you have any thoughts on whether we should be more or less worried about those things versus the risk of a nuclear war?

Dave Denkenberger: I think as you’ve pointed out on other shows, the natural risks are probably lower probability. But the interesting thing about solar storms is that it’s a new threat in a way, because a solar storm 1,000 years ago was not going to hurt us. But now that we have this electric system that could be damaged, that’s a newer thing, so I think there’s some threat there. I think [a solar storm] is unlikely to be global, but I think even a regional disruption of industry or electricity is a significant shock — and would also likely be accompanied by a food production shock.

Rob Wiblin: Is there much to say about how swiftly we might be able to respond to something like an electromagnetic pulse that damages the electricity grid? Do we have a good idea about how much damage that would do and how hard it would be to fix? Or are we left to some extent to speculate about that?

Dave Denkenberger: There’s some debate, and former guest David Roodman has done some analysis on this. We’re actually working on a global analysis, looking at the impacts of a solar storm. But I think that in the case of the solar storm, there might be some things we could do ahead of time, if we detect it, because we might have a few days and be able to turn things off. The EMP is tough.

Rob Wiblin: It’s by nature a weapon that would be designed to be a bolt from the blue. That would be the aim.

Dave Denkenberger: Right.

Rob Wiblin: Are we sure that if you detonate a nuclear weapon at high altitude, it has this effect? Has it ever actually been tested?

Dave Denkenberger: It has. And in fact, we accidentally discovered how destructive it could be in the first test. Because it interacts with the atmosphere, it had a much greater radius of impact, and disrupted electricity I think on Hawaii, very far away from the original test.

Rob Wiblin: Wow, okay. Interesting. So we discovered this effect basically through testing. Have we ever gotten to the point where it’s like, “Oh, we’re going to break electricity grids,” or test it at that level?

Dave Denkenberger: I think there was a test in the Soviet Union that was closer to people and there was disruption.

Rob Wiblin: Had that effect. Interesting.

Dave Denkenberger: And some people have said there may be these super EMP weapons developed at some point, and they could be even more destructive, but even just regular nuclear weapons are quite destructive.

Rob Wiblin: Do you want to comment at all on the probability of us going from a pandemic or an electricity disruption to having disruption of agriculture and significantly less food for a while?

Dave Denkenberger: I think modern society is extremely dependent on electricity, so there are these interdependent webs of causality here. If you lose electricity, you lose typically a lot of fossil fuel production, you lose communications. So basically, you’d have a collapse of industrial civilization. Now, what we want to avoid is the full collapse of civilization, which includes cooperation outside of small groups.

Dave Denkenberger: But if we lose this industrial production, then there are some immediate needs. ALLFED has a catastrophe planning expert who used to work in the Royal Air Force. He has this rule of thumb that you’ll die in three minutes without air, three hours without shelter, three days without water, and three weeks without food. So fortunately, we’re still going to have buildings, but we’d need to heat those buildings. And then we also need to provide water very fast.

Dave Denkenberger: So we are looking at how many people live close to water, such that they would not have to move locations and still gather water. But then eventually it’s going to impact food, because right now our system is very dependent on artificial fertilizers, pesticides, tractors, irrigation, et cetera. At least the sun would still be shining, but it would require dramatic scaling of hand or animal tools to farm, which we’re still working on. But we do have some estimate of the direct impact on agriculture of losing these industrial inputs: it’s something like cutting production in half.

Rob Wiblin: Okay, interesting. I guess we’re slightly skipping between quite different scenarios here. So if you have a global pandemic where the fatality rate is much worse than with COVID-19 — such that people are much less willing to go to work — the fear would be that even if people are told very forcefully that they need to go and continue farming because otherwise people are going to starve, it might be hard to get people to do that.

Rob Wiblin: It seems like in that case, a lot of these alternative foods don’t help so much, because you would still have to have people gathering together in order to grow these things, whether it’s seaweed, or greenhouses, or whatever else. People would be similarly reluctant to go and do that. Am I misunderstanding?

Dave Denkenberger: I think it’s a little different because in the case of just losing electricity and not having disruption of the sun, we can still farm by hand, basically, or animal power. That can be done outside and at a low density of people. You don’t have to have people working together so much. If you think about subsistence farming, it’s a more lonely job. Now it could be, especially if there’s a trade disruption — and trade would be more difficult of course in these scenarios — that just hand farming is not going to produce enough food. Certainly, especially regionally. Then it could be that you want to do some of these more resilient type foods.

Rob Wiblin: Yeah, interesting. Okay, so I guess one pathway for a pandemic creating problems is also that people have speculated that eventually it could cause the electricity grid to go down if enough skilled people have died, or people are just completely not showing up to work even to run basic services like that. Setting aside whether that’s likely, I guess anything that helps with an EMP attack or any solar storm also helps with this scenario where the electricity grid goes down for any other reason.

Rob Wiblin: I guess you’re saying there’s some ways that you could make food, like subsistence agriculture or just farming on your own that don’t require close collaboration or people getting together in buildings quite as much — at least not in the long term once people are actually out on the land doing things. So we might want to have some process of figuring out how we would reorient how we’d produce food, such that it involves less interaction between people.

Dave Denkenberger: Yeah and so that’s an added benefit, that it could also work in a pandemic scenario.

Rob Wiblin: Yeah, yeah. Okay, coming back to the electricity grid one: I guess an EMP, it’s at least somewhat local. Well, you could potentially have people setting them off all over the place, but potentially it could be a local thing. I guess solar storms as well, they tend to target particular parts of the Earth that happen to be hit by them. In that case, I wonder whether you just want to move all of the people to other places where the equipment is still running and the electricity grid is still up. Maybe that’s the best way of producing lots of food, is just to get people to places where it’s going to be easier to work. Does that sound plausible?

Dave Denkenberger: Yeah, that’s one option, assuming that people are —

Rob Wiblin: Transport’s open.

Dave Denkenberger: Well, yeah. And that there’s enough cooperation that they could handle hundreds of millions of migrants.

Rob Wiblin: Yeah, yeah, interesting. Okay, so we’ve talked a bit about electricity. You also raised the issue of communication going down. How long do you think it would stay down, and how severely would it be down, and how big a problem might that be?

Dave Denkenberger: Again, it depends on if it’s regional or global. And I think even though it’s unlikely, it’s possible that there could be multiple EMPs around the world. You look at a full-scale nuclear war between Russia and NATO, then you have most of Europe. It could even spread to other nuclear powers. I mean, that’s the majority of the world’s population and infrastructure.

Rob Wiblin: Yeah, so it’s a lot of people covered potentially. Couldn’t people still communicate by… I don’t know, I guess are there sorts of radios that work for this, if you really needed to? Or, I don’t know, maybe the mail? I guess mail might be down.

Dave Denkenberger: Yeah, or mail would be slow, on horses and such. So one thing we’ve looked at is shortwave radio, or sometimes known as ham radio, and they use a frequency that you don’t need to produce that much power. You can have a $20,000 system that can actually communicate across an ocean. So it could only be a few million dollars to have a backup communication system, and this would be extremely valuable — especially if the catastrophe were abrupt, that we didn’t have the internet to learn about what to do in this circumstance. So that we could get messages out of what to do, how to meet basic needs — at least in the first few weeks, and then buy us some more time.

Rob Wiblin: Yeah. I guess it seems like most countries do some stuff to prepare themselves against disasters. It seems like this would be well within the budget to have ham radios in major cities for this purpose.

Dave Denkenberger: There are some, and I think the issue is that countries will have systems for themselves, and not every country has it. So what we’re interested in is doing a global system backup.

Rob Wiblin: Interesting. Okay, cool. Is there much more to say on the solar storm, EMP, pandemic problems?

Dave Denkenberger: We’ve also done a cost-effectiveness analysis for these interventions, and it’s actually only for the long-term future perspective, but I think there are, again, some mechanisms that this type of a loss of industrial civilization could cascade downward to loss of conventional civilization. I mean, the last time we were hunter-gatherers, there were only a few million people on Earth, so 99.9% mortality — and again, are we sure we’re going to recover from that?

Is New Zealand overrated? [01:25:35]

Dave Denkenberger: It’s been pointed out by many people that the situation in New Zealand could be pretty good in nuclear winter scenarios, potentially a pandemic. But I question that, partly because people can move. If people can recognize there’s lots of food in New Zealand, then I’m concerned that there will be a lot of migrants that would overwhelm that food supply.

Rob Wiblin: Yeah. There’s a bunch of things to say about that. I guess, it’s a long way away, so inasmuch as it’s hard to travel, or ships are damaged, it maybe could just be difficult to make the journey all the way to New Zealand. I guess from a do-people-survive point of view, if lots of people moved to New Zealand, maybe only a fraction of them end up surviving, because it’s now overpopulated relative to what it could support. But it seems like at least some of them should end up surviving, unless they end up destroying all of the infrastructure in the process of fighting over who gets to be there. How are you envisaging this playing out in your mind?

Dave Denkenberger: I think the question is, do you think the food supplies could be sufficiently protected? Because if all of a sudden we have half as much food, if the food is shared equally, everyone’s going to die. So you have to be really confident that some food will be protected.

Rob Wiblin: But don’t people progressively starve? And then the people who are left, in a sense, you end up with the number there that is… Do you see what I mean? It’s hard for us to go to full extinction. This thing of “lots of people would move to New Zealand and so they wouldn’t survive” has a bit of this property of, like, “No one goes there anymore, it’s too crowded.” Where eventually, the population has to keep lowering until the amount of food throughput is enough to sustain the people who remain.

Dave Denkenberger: That’s if there’s food production. But the concern is if we are above the carrying capacity and everyone… Let’s say we divide up the food we have remaining, and everyone has one year of food, and the sun is blocked for five years — then everyone’s going to die. So you basically have to protect stores of food for some people.

Rob Wiblin: Yeah. I guess the hope with New Zealand was that you would still be able to produce food reasonably well there, maybe have to change crops to some degree. You would also have a lot of seafood, potentially. A lot of ability to grow seaweed because there’s a long coastline. So, the hope would be that there’ll be significant production there. But I suppose if you’re also in the middle of a war, because another country is invading you in order to get access to that land, then that production might be a lot, lot lower.

Dave Denkenberger: And also if people are desperate, they’re going to eat the seed corn and then you can’t grow anymore. It’s the same thing with fishing: if you fish the fish to extinction, then you don’t have any more supply.

Rob Wiblin: Yeah. It seems like that would require a lot of shortsightedness. Although I suppose I wouldn’t put that past humanity, potentially. I guess this is one reason why you want to promote the message even in New Zealand, that it would be possible to feed everyone, or to feed a lot of people — to try to get them to be thinking longer term and to be thinking about production, rather than just protecting the supplies that they already have. And then you want them to worry about eating the seed corn, effectively.

Dave Denkenberger: Well and globally, such that people could be fed where they are now and then they don’t overwhelm New Zealand.

Rob Wiblin: Okay, I see. So this ties back into the plan of feeding the whole world, in that if people around the world think that their best bet is to stay put and try to produce food, then you don’t end up with these mass migrations and all of the chaos and disruption of production that that might entail.

Dave Denkenberger: Right.

Should listeners be doing anything to prepare for possible disasters? [01:28:43]

Rob Wiblin: Should listeners be doing anything in their own life potentially to prepare for some of these possible disasters? I suppose there’s like a reasonably long list that we’ve talked about, but do you have any lifestyle advice?

Dave Denkenberger: Well, there’s a general recommendation of having two weeks of food. And you can justify that just based on an extended hurricane outage, so I think that’s pretty obvious. I personally don’t store more food than that because I’m more interested in keeping the whole system functioning.

Dave Denkenberger: But another thing I do think about is that I think there is a significant risk of full-scale nuclear war. And so I’m personally concerned that so many EAs are living in typically the city centers of NATO cities. And it’s interesting that their typical city real estate prices are such that it’s more expensive to live in the city center than in the outskirts, because in the outskirts you have a long commute.

Dave Denkenberger: But this gradient in real estate price is generally not taking into account the risk of nuclear war, because most people just ignore it. So you could potentially exploit this. And if you are concerned about the risk of nuclear war, living further away could be optimal, especially if you could have a commute where you could multitask.

Rob Wiblin: Yeah, right, right, right. Or I guess now, if you can work remotely.

Dave Denkenberger: Exactly.

Rob Wiblin: People spreading out because it’s harder for everyone to get killed that way. Yeah you’re right. And I guess a lot of listeners to this show, I can see in the analytics that a lot of people are in London, Oxford, SF, LA, New York, Sydney, Berlin. Yeah, all probable targets. Except maybe Sydney. I’m not sure about Sydney. Well, maybe once they have these nuclear submarines that they’re talking about, then they’ll target Sydney as well. Interesting idea. How far away do you have to live from a city center to not get toasted?

Dave Denkenberger: It really depends on how many nuclear weapons are used and whether it’s just the US as the target or all of NATO. But I think that just living on the outskirts of a city is quite a bit lower risk.

Rob Wiblin: Easy enough. Okay, nice.

Dave Denkenberger: And you could also live in a smaller city, but that might not always be feasible.

Cost effectiveness of work on EMPs etc [01:30:43]

Rob Wiblin: Yeah. Okay, interesting. Okay, was there much more say on the cost effectiveness of these alternative concerns like EMPs and so on?

Dave Denkenberger: In our cost-effectiveness model, again, we’re looking at the high-leverage opportunities. And in a way, I think it would be less expensive to get ready than for the resilient foods for nuclear winter, because we don’t have these expensive factories we need to pilot — we won’t be able to make factories. So the experiments will probably cost less, but we do need this radio backup system. But again, a few million dollars or so gets us pretty far. So we’re talking in the range of something like $100 million.

Dave Denkenberger: If you do think there’s plausible long-term future impact, then we compare it to an AGI safety model, and again, lots of uncertainty, but it seems to be competitive, at least at this lower funding amount. I remember when we posted this on LessWrong, one person summed it up and they’re like, “Well, yeah, we should spend 1% as much money as we’re spending on AI safety.”

Rob Wiblin: Yeah, yeah, makes sense. I guess, while we’re on the cost-effectiveness analysis, last time around, we talked about these papers that you’d written, that you mentioned earlier, estimating how much it would cost ALLFED to save a life in expectation. And sometimes those analyses would come out with very low numbers, in the hundreds or even single dollars, potentially. I guess some folks thought that was too low and there was a bunch of debate going on online about those estimates. Yeah, how has that conversation played out since we last spoke?

Dave Denkenberger: Yeah, certainly people have different intuitions in the cost and the effectiveness, but I think that overall, these resilient foods and then the interventions for loss of electricity are just so neglected that I think there’s a good case that it’s cost effective at the margin now.

Rob Wiblin: It seems like you’ve been making a lot of progress on analyzing these various different options over the last couple of years. It feels to me like your knowledge about which ones are most promising seems significantly more developed than it was in 2018.

Dave Denkenberger: Yeah, we like to think so.

Rob Wiblin: Okay, cool. I guess it kind of seems to me that, given the total amount of funding that’s available for catastrophic risks — and also for more neartermist effective altruist projects — that growing ALLFED isn’t super close to the margin. Or maybe it’s not necessary to spend a lot of time debating exactly how many lives you save per dollar using this approach, because it’s relatively straightforward that we should be funding it to a reasonable degree anyway.

Rob Wiblin: Maybe if you were advocating for a massive scale up in the order of hundreds of millions or something, then we might want to have more of a dispute about how it compares with other things. But at the current scale, it seems like the time is better spent looking into the foods maybe, rather than debating exactly the cost effectiveness.

Dave Denkenberger: I would be happy to move on from cost effectiveness, but I think that we’re still not seeing the response we’re looking for in terms of being a significant part of the existential risk portfolio.

The future of ALLFED [01:33:34]

Rob Wiblin: Let’s talk about that. So for ALLFED to really flourish and grow in coming years, what would you be seeing it doing?

Dave Denkenberger: One of the things is really proving these things out, like we talked about — doing actual factory experiments, or for the cheaper experiments, smaller scale — and show that we can do this fast and we can feed people.

Rob Wiblin: Are there any particular experiments? Do you have a prioritized list of what you’ll do first and what you’ll do second, depending on how much funding you got?

Dave Denkenberger: One that we think is particularly promising is this repurposing of a small paper factory, because of the low-cost food.

Rob Wiblin: That makes a lot of sense. Do you have a sense of how much it would cost to rent out a paper factory for a while and give it a crack?

Dave Denkenberger: It really depends on the size, but we are talking millions of dollars. Now, we would hope to be able to get some co-funding from the industry itself, if they see some value in this. But we do need significantly more investment.

Rob Wiblin: And where is most of that going? Is it operating? Renting these large amounts of equipment? I guess you also need to buy timber, and you probably need some skilled people to figure out how to reconfigure the factory?

Dave Denkenberger: Right, we need those extra components.

Rob Wiblin: I see. So you take the mill. It’s got a lot of the stuff you need, but then you need to add various different other pieces of equipment that you would have to buy specifically for this purpose.

Dave Denkenberger: Right.

Rob Wiblin: Okay, cool. So if you wanted to do that and a bunch of other experiments, what sort of funding level are we talking about per year, do you think?

Dave Denkenberger: Well, it’s interesting. People have been talking about these megaprojects within EA, because the funding resource has grown significantly. And so I’ve been talking about on the order of a few hundred million dollars. Now there’s a question of how fast it would make sense to spend that, and there are some advantages to learning along the way and reprioritizing. But these catastrophes we’re talking about, most of them could happen very soon, and so I think there is a lot of urgency to get this preparedness. And so I think it would make sense to spend this money in the next five or 10 years, so that it really could be a megaproject.

Rob Wiblin: Yeah. What sort of funding do you already expect to get? I guess you already have some donors who take an interest and probably donate semi-regularly. Where do you expect to be if you don’t find anyone new?

Dave Denkenberger: We’re very grateful for the funding we’ve received, including from the Centre for Effective Altruism, Jaan Tallinn (who’s also on our board), the Berkeley Existential Risk Initiative Survival and Flourishing Fund, and many smaller EA donors. But it’s hard to know whether some of these are one-time or continuing.

Rob Wiblin: Why do you think it’s been challenging to raise the sort of funding that you want? Is there a way in which it’s falling between the gap? Where like, the hardcore existential risk people want to focus on AI maybe, and the people who want to focus on saving lives today want to focus on something that’s more provable and less of a hit hits-based approach?

Dave Denkenberger: Yeah, I think that is a big part of it, which is why we’re interested in how big of a long-term future impact these catastrophes have. The other obvious source of money is outside of EA, but then it’s the opposite problem: it’s hard to get them to consider catastrophes that have already happened — like the year without a summer in 1816, which caused famine in parts of Europe.

Rob Wiblin: Don’t be ridiculous, Dave. That would never happen. Sorry, go on.

Dave Denkenberger: We are hopeful that with COVID, now some of these catastrophes are more imaginable, but we still haven’t seen the fruits of that yet.

Rob Wiblin: What sorts of people have you approached about the more normal-seeming food shock, like a volcano that interrupts agriculture?

Dave Denkenberger: Yeah, or these climate risks. Even the slow climate change of a few degrees C, I think that could inflate food prices — that could make some of these resilient foods, like seaweed, more cost effective. But even more severe are the abrupt climate change scenarios, like a loss of 10 degrees Celsius over our continent in one decade — that’s happened to Europe before, so it could happen again. And that’s considered a tail risk that’s much more severe than what most people are thinking about, so we think it makes a lot of sense. The question is whether they can actually incorporate it into their financial models.

Rob Wiblin: So you’ve approached governments and foundations about this sort of thing, and this kind of risk management of unusual things just isn’t on their radar? Or they kind of stare back blankly at you?

Dave Denkenberger: Yeah. I mean, talking to World Food Programme, they’re just stressed out with the current food situation and just can’t think of anything bigger.

Rob Wiblin: I guess we’ve seen that there’s some various potential connections with the reducing reliance on animals and reducing factory farming folks. I wonder if there’s any potential funding streams there from people who are interested in alternative proteins, which happen to line up with resilient foods.

Dave Denkenberger: We’ve talked about the fermentation and the seaweed, but I think what would also be relevant is the leaf protein concentrate, because that could potentially be used as a meat substitute.

Rob Wiblin: Do you have many donors who are earning to give to support ALLFED, among other organizations?

Dave Denkenberger: Yeah, we do have some. And there is this interesting concept “earning to give plus” — that it may be harder to earn to give and maintain motivation in comparison to working at an EA organization, because you’re not surrounded by like-minded people as much. So the idea is to have more interaction with the charity that you’re giving with, perhaps volunteering or being a part of the process.

Rob Wiblin: Do you have any earning to give people who are volunteering as well, or at least stay in regular touch?

Dave Denkenberger: Yeah, to some extent, but we want to look into it more.

Rob Wiblin: That sounds like it could be a pretty fun path. So there’s obviously potential donors to ALLFED in the audience. Do you just want to directly make a pitch to people to maybe go on the website and learn more about what you’re doing and consider donating?

Dave Denkenberger: Sure. So yeah, we actually have a new website and we accept crypto as well. I think that on a number of value systems — whether it’s neartermist or longtermist — we’re working on something that is highly neglected, large scale, and it’s quite tractable. I think that there are clear paths to make progress, to prove out these technologies, and really get governments and corporations ready to scale up food production in a catastrophe.

Rob Wiblin: It does just seem like you’ve got such fertile terrain to run trials on all these different options and see whether the things that you’ve been saying here, or the estimates, are approximately right. If, broadly speaking, what you’ve been saying is shown to be right, then it does seem like we can go from expecting most people to starve in a lot of these cases to expecting most people to make it through.

Rob Wiblin: And that it might not even be that challenging, or we just need to do some planning ahead of time and make sure that lots of people are aware that this is what they should be thinking about, should there be a massive food shortfall. And have lots of books describing these different options and how to scale them up distributed all over the place — that could actually just go a ton of the way by itself.

Dave Denkenberger: Yeah, I think that’s right. And especially in the case of the loss of communication, that’s the other way — if we can get the message out ahead of time. But of course, if you get the information out and then things don’t go according to plan, it’s good to have that feedback, so having a two-way communication system.

Opportunities at ALLFED [01:40:49]

Rob Wiblin: Makes sense. Pushing on from funding to people, what current vacancies do you have open or might you expect to have open over the next six to 12 months?

Dave Denkenberger: Well, right now we’re really focused on fundraising. But Joshua Pearce — the coauthor of the book Feeding Everyone No Matter What — just switched universities, and he has funding for several PhD students. He’s interested in bringing them on and working on some ALLFED-related stuff.

Rob Wiblin: What sort of PhD projects? Is he an engineer or more involved in agriculture?

Dave Denkenberger: He’s an engineer. He’s particularly excited about the leaf protein concentrate also, because of mitigating current malnutrition — it’s a good source of protein, but also a number of vitamins. And so we have a recent paper where we were mapping out the leaf resources globally and where there’s current malnutrition. We still need to do more work on what leaves are actually nontoxic, but he has a fancy piece of equipment that can run toxicity analyses, and he’s working on an open source program that’ll make it much lower cost to run these analyses.

Rob Wiblin: Are there any skills or aptitudes that you could see potentially being a bottleneck for you in the future, if you were to get something in the tens of millions of funding, perhaps?

Dave Denkenberger: We certainly are interested in more GIS analysis when we start looking at this country by country.

Rob Wiblin: What’s GIS?

Dave Denkenberger: Geographic information systems. And there’s a lot of coding associated with that. We’re definitely interested in more people with knowledge of policy and international relations, so that we can have a better idea what cooperation scenarios might be plausible.

Rob Wiblin: Interesting. What kinds of academic backgrounds do the people at ALLFED mostly have? Is it lots of engineers or more wide ranging?

Dave Denkenberger: It’s a fair amount of engineers. We also have some social sciences. We had a regular call, which we called CRASSH — Catastrophic Risk and Social Sciences and Humanities. And one of the things we were looking at is historical analogs, like past pandemics, because we were concerned about the food impacts. So it was great to have contributions from history and sociology.

Rob Wiblin: I imagine historians of war might have a bunch to say about this. You were talking earlier about Germany converting coal to lipids that people could eat during World War II. I wonder whether there’s other cases that people might be aware of if we looked into it enough. I suppose that might not be cutting edge in any case.

Dave Denkenberger: Well, there is a book called Famine Foods, I believe, that looks historically at what people have eaten in famines.

Rob Wiblin: Did you get any of the ideas from there, or is that a separate stream of things?

Dave Denkenberger: There may be something. Some people are looking into the inner bark or the cambia of trees: you can take the bark off and then strip that living layer of the tree off and make it into a flour.

Rob Wiblin: Interesting. I guess that kills the tree in the meantime.

Dave Denkenberger: Yes.

Rob Wiblin: I’m guessing that’s somewhat limited, because, well, it sounds like a bunch of work. Also, you can’t get that many calories from that in total I would imagine.

Dave Denkenberger: Right.

Rob Wiblin: So it seems like semi-inspiration potentially for doing the pulping into sugar thing. This is the first cut of turning wood into food, but then there’s a whole lot more that we can do beyond that with the rest of the tree.

Dave Denkenberger: Right.

Rob Wiblin: I guess an unusual thing about ALLFED’s approach is that it makes use of quite a lot of volunteers. How does that work?

Dave Denkenberger: Well, I think it is a little bit easier for us in general, because we can employ many different fields. And also you don’t need to have a lot of background information because we’re asking really new questions, so I think it’s easier to make progress. And there’s lots of people in EA that want to skill up in research. We also have some volunteers that are doing things other than research.

Dave Denkenberger: We have a pretty formalized system. People come in and they do a taster task so that we can see if it’s a good fit for them and a good fit for us. And then on the research side, we have a weekly team meeting where we try to get as many people together at the same time so people can see what other people are doing. But then we also have smaller group calls that are focused on particular topic areas — like the “green gang” was the photosynthetic people — and those are the people that are typically coauthors on the papers. And also it’s nice that sometimes a volunteer will have to leave, but then the other people on that small call can pick up the work.

Rob Wiblin: So you do have some attrition rate, but people are working in groups such that the knowledge carries through.

Dave Denkenberger: Right.

Rob Wiblin: Has this prompted people to potentially scale up their interest in these things, and then maybe go on and do a PhD or something in these topics, based on their exposure as a volunteer?

Dave Denkenberger: Yeah, we have one person who is getting a relevant master’s, and also several people have transitioned to full-time work at ALLFED from volunteering.

Rob Wiblin: Nice. I recall that you have quite a lot of thesis ideas on effective theses. Is that right? Is that still the case?

Dave Denkenberger: Yeah, around 60 or so.

Rob Wiblin: 60? An abundance of different thesis options.

Dave Denkenberger: We just had a student recently complete her thesis in Germany. It was on the agricultural yield in the losing-electricity-and-industry scenarios.

Rob Wiblin: I guess something that’s kind of convenient about this sort of work is that each of these streams of possible projects can to some extent be conducted independently. So the seaweed people can continue pursuing the seaweed thing and see whether it bears fruit, and then the people focused on the hydrogen thing can do that. And they don’t necessarily have to talk to one another a ton. Is that right, or is there maybe more need for coordination than I imagine?

Dave Denkenberger: I think quite a bit can be done independently, but then of course to do the integrated model we have to look at all the interactions.

Rob Wiblin: That makes sense. Do you think that’s likely to be a structure that you have? That you have some people in the middle coordinating and maybe prioritizing between these things as information comes in, but then you have hopefully lots of people to some degree independently — maybe just as part of their academic research in general — investigating these different possible opportunities and figuring out how viable they are?

Dave Denkenberger: Yeah, I think that’s right.

Rob Wiblin: If people are interested in volunteering, or possibly already working on something a little bit adjacent, how can they get in touch?

Dave Denkenberger: Well, one easy way is just to go to our website, allfed.info, and there’s a contact page.

Why Dave is optimistic around bigger-picture scarcity issues [01:46:58]

Rob Wiblin: Let’s push on from ALLFED and resilient foods, and maybe talk about bigger-picture scarcity issues. Given all of the above, folks might expect you, Dave, to be a bit pessimistic about humanity’s prospects, because we’re talking about doom and gloom and how to prevent famines and so on.

Rob Wiblin: And a lot of people who worry about food shortages and famines like you do also worry about civilization running out of all kinds of other resources, and potentially crashing and burning as a result in the coming decades, because of climate change or whatever else.

Rob Wiblin: But I saw in your notes that you tend to be actually, relative to the mainstream culture, pretty hopeful. Very hopeful, I’d say, that we can solve most of those problems, barring the kinds of catastrophes that you’re worried about really throwing us off track. Maybe we could go through a bunch of different things that people worry about, potentially creating big problems in the coming decades, and you can react to them from an engineering perspective. Sound good?

Dave Denkenberger: Sure.

Rob Wiblin: I guess energy is a classic one. What do you make of the idea that we might not be able to make enough energy to support things?

Dave Denkenberger: Right. So recently Carl Shulman provided some answers on this. But I think that in addition to thinking about solar and wind, there is this concern of intermittency that the wind’s not always blowing and the sun’s not always shining. And he mentioned that we could use chemical batteries to even that out. And that’s true.

Dave Denkenberger: But it turns out, there are some lower-cost ways of doing that. And one of the research projects I had when I was at Princeton was looking at compressed air energy storage. So you need somewhere to compress the air. That could be an aboveground tank, though that’s fairly expensive. But better is compressing it, like in a mine. Or even just pump the air underground into an aquifer — you’re just displacing the water. And it turns out this is much less expensive, especially if you’re storing the energy for a longer period of time, like days. And you do need to store it longer, in the case of wind especially.

Rob Wiblin: Yeah, so is there a way of thinking about the cost of these different things? Like what’s the amount of energy stored per… I guess per hour per dollar might be the measure of efficiency, right?

Dave Denkenberger: Well, it’s sometimes helpful to think about the difference between power and energy. Power is the rate of use of energy, so if you don’t need energy for very long, a chemical battery is good, like in a car. But if you need a long time, you need some way of storing a massive amount of energy. And so rather than building something like a battery, if you can just use air, then it’s much cheaper.

Rob Wiblin: So what are the pros and cons of compressed air?

Dave Denkenberger: The way it’s currently run, one of the cons is that when you compress the air, it would normally get really hot. So you actually cool it down in between and then you inject it in the ground. But then since it’s cool to start with, if you let that decompress, it would get to very low temperatures. So typically they burn a little bit of natural gas. Now there are ways around that, but that’s the cheapest way of doing it now.

Rob Wiblin: Okay.

Dave Denkenberger: But still looking at the overall carbon emissions of this, it’s an order of magnitude lower than a pure fossil system.

Rob Wiblin: Yeah. And how does it compare to batteries or pumped hydro in terms of cost effectiveness?

Dave Denkenberger: Much better on the longer-term storage. But pumped hydro is another good one. Even just regular hydro, it’s nice that you can turn it on and off easily. But pumped hydro is where you take this generator and turbine and run it backwards so you’re pumping the water uphill. And again, you’re using water, so it’s a really cheap way of storing energy.

Rob Wiblin: As I understand it, the limiting factor with pumped hydro is having enough nice dams to conveniently store the water? Or people would like to scale hydropower and they’d like to scale pumped hydro, but we’ve kind of already built many of the dams that are most practical given the geographic constraints?

Dave Denkenberger: Yeah, the pumped hydro is more geographically constrained.

Rob Wiblin: If compressed air is reasonably cost effective, especially in underground mine shafts or aquifers, why don’t we use it now very much?

Dave Denkenberger: Right now, in most places, the penetration of renewable energy is not very large. So we don’t actually need storage. And then, as it gets larger, we might be able to store it for an hour or two, and chemical batteries could work well for that. But for the very large renewable energy penetration, then we need more like days of storage.

Rob Wiblin: Okay, so you think that potentially in coming decades, as wind and solar become a large fraction of the energy supply, and we want to be smoothing out our access to energy over days — or possibly even weeks, I guess — that compressed air could become a really big deal?

Dave Denkenberger: Right. And then in the extreme case, if you want to store energy seasonally, you can generate hydrogen and pump that in underground aquifers.

Rob Wiblin: And then burn it when it comes out, right?

Dave Denkenberger: Right.

Rob Wiblin: So the underground is where you store the hydrogen?

Dave Denkenberger: Yeah.

Rob Wiblin: Okay, is there a way of communicating the cheapness of this? Or maybe is it a bit too early in the development of the technology to say how much this would add to the cost of electricity?

Dave Denkenberger: Roughly we’re only talking about one or two cents per kilowatt hour increase.

Rob Wiblin: Okay. So at the point where you consume it, that’s like a five or 10% increase, or on that kind of order?

Dave Denkenberger: Right.

Rob Wiblin: Okay. Yeah, anything else to say on issues of us not having as much energy as we want in the future?

Dave Denkenberger: Another thing I would say about mitigating this intermittency problem of renewables is that we can also make the demand more flexible. This could be smart appliances, but a big one that I’ve worked a bit on is thermal storage in buildings. So we have this air conditioning that has a very peaky profile — a lot of air conditioning in the hottest days. It’s much more efficient if you could chill water at night and then use that over the day. And you can actually make your air conditioner cheaper because it runs a greater portion of the time.

Rob Wiblin: At night when, in principle, electricity could be made cheaper, basically.

Dave Denkenberger: Right.

Rob Wiblin: Okay. So you suck up the electricity when there’s lots of it, and then you cool down water, and then the water cools down your house. Or you can then circulate the water through the house potentially.

Dave Denkenberger: Right.

Rob Wiblin: Interesting. Okay, yeah. Any other thoughts on energy? I guess there’s been a lot of chat lately about nuclear energy. It seems like it’s back on the agenda and people are reconsidering it. Did you have any thoughts on that?

Dave Denkenberger: Yeah, I think it’s promising. Of course, you don’t have that intermittency problem so that’s one big advantage. And as part of my day job as a professor, we’re looking at nuclear microreactors. Because Alaska doesn’t have very many people, so the only reactors that make sense —

Rob Wiblin: One might be too many.

Dave Denkenberger: — are these microreactors. So a very large power plant — could be nuclear or could be coal — is around 1,000 megawatts or a gigawatt of power. But these microreactors could be one to 10 megawatts, and they’re looking at making them passively safe and very low maintenance. And I think there’s a lot of potential, especially in remote areas where they’re using very expensive diesel-generated electricity.

Rob Wiblin: Do you have any thoughts on if nuclear power is a cost-effective way of producing energy compared to alternatives? I think Mark Lynas, in our interview with him last year about climate change, he thought that wind and solar would run into this impediment that you would find it very hard to get approval to cover as much land as you would need with them, because you just wouldn’t be able to get planning permission basically.

Rob Wiblin: And also in places like the UK. that are very population dense, there actually might just be a shortfall of land relative to what you need to power the whole country. I guess he thought that nuclear power would end up being a whole lot cheaper. But this is a very disputed claim. Do you have any thoughts on that?

Dave Denkenberger: Well, certainly nuclear is very low land use. But then yeah, recently, there’s been discussion with Carl about the regulatory environment, so that’s certainly a barrier. I would say for wind turbines, the actual land lost is very small, if you just look at the foundation and the access roads. So we’re not really taking significant land away from agriculture.

Rob Wiblin: Right.

Dave Denkenberger: Solar panels, of course we can do some on our roofs, but that’s not going to produce all our energy. I think one interesting application is putting them in drier areas. Because right now, in a dry area, it’s limited by precipitation, not by sunlight.

Dave Denkenberger: So if you have solar panels above them, they’re actually reducing how much sunlight is coming down to the plants which doesn’t hurt them. And it actually helps them because then they’re dried out less. So you might actually increase the agricultural yield under these solar panels.

Rob Wiblin: That’s very interesting. You’re saying if you’re farming in an area where there’s lots of sun but not much water, then putting solar panels on top — or like partially shading them — might cost you almost nothing, or like actually a negative amount in terms of agricultural productivity. But then you are capturing all of that sun that otherwise would be wasted because the plants wouldn’t have enough water to photosynthesize anyway.

Dave Denkenberger: Right.

Rob Wiblin: Yeah, okay, interesting. That’s very cool. I’ll see if I can find a link to something about that. I guess sometimes people say if we scaled up nuclear energy a whole lot in the way that Mark Lynus would want, we would run out of uranium. Do you have any thoughts on that?

Dave Denkenberger: Well, there’s a few things. I mean right now, the way we do it, we don’t use very much of the fuel. But there is reprocessing that’s already happening. There’s the possibility of breeder reactors.

Rob Wiblin: What are they?

Dave Denkenberger: So I’m not an expert here, but my understanding is that through the operation of these plants, they’re actually producing fuel that can be used in the future. And so I think you can reduce how much you have to mine by at least an order of magnitude.

Rob Wiblin: Okay, yeah.

Dave Denkenberger: Then there’s just the question of if we’re going to run out of mining eventually. And it turns out the actual cost of uranium is a very small cost compared to the total cost of nuclear electricity, so we can afford to have it increased. There’s even been demonstrations of pulling uranium out of ocean water.

Rob Wiblin: Which I guess is expensive, but then it might still be a small fraction of the total cost of the plant.

Dave Denkenberger: Right.

Energy return on energy invested [01:56:36]

Rob Wiblin: What other resources do you have thoughts on, where you think maybe mainstream pessimism is mistaken?

Dave Denkenberger: I think there’s this concern about the energy return on energy invested. And this is a concept that says, “If I build a solar power plant, I’m going to take some energy to do that. And then how much energy do I get back out?” And so obviously for this to be useful, you have to get more energy out than you put in. So that ratio has to be at least one.

Dave Denkenberger: And people have pointed out that for fossil fuels, it’s typically very high. Like over 10 times as much energy you get out than what you put in. For renewable energy, it’s not as high — maybe it’s only three or five. And there are some people that have said, “Well, in order to have a modern industrial economy, you need to have this ratio be five or even 10.”

Dave Denkenberger: So I looked at the paper and it doesn’t seem to be supported. Because basically, say you have an energy return on energy invested of only two. That means you have to make twice as much energy and you only get to use half of it.

Rob Wiblin: Yeah, because half of it goes into making the energy again.

Dave Denkenberger: Right. So roughly, cost of energy goes double. But it’s not that large to start with. So it’s not catastrophic.

Rob Wiblin: Yeah.

Dave Denkenberger: Now some people have pointed out that you get these high-energy returns on energy invested for solar and wind because we’re producing electricity. And every unit of electricity is displacing three units of fossil fuel if the power plant is only one-third efficient, roughly.

Rob Wiblin: Okay.

Dave Denkenberger: But what if you actually need a fuel to run your car? Then you have to use the electricity and you maybe could, say, turn it into hydrogen. Now you’re not substituting for so much fossil fuel — it’s more like one to one. And that is a valid point that your energy return on energy invested is not as good if you’re making a fuel.

Rob Wiblin: This is because of the inefficiency involved in converting electricity into hydrogen and then the hydrogen into movement?

Dave Denkenberger: Yeah, so that’s part of it. But even if that were 100% efficient, you still have the issue that then that hydrogen substitutes for only one unit of gasoline or petrol.

Rob Wiblin: Oh, and this is because of the inefficiency of converting fossil fuels into electricity, where you actually lose most of the energy. Even in a coal plant, I think you lose most of the energy, into just heat.

Dave Denkenberger: Exactly. So there are concerns that then the energy return on energy investment is going to be a lot lower. And if we get below one, we’re in big trouble. But if you look at this economically, right now fuels are much cheaper than electricity. Because right now, it takes three units of fuel to make a unit of electricity and you have to pay for the power plant.

Dave Denkenberger: So we use a lot of fuels directly, like in our cars and heating houses. But if now our fuel is hydrogen, that’s going to be more expensive than electricity. So we’re going to use much, much less of it. We’re going to use electric cars and we’re going to use electric heat pumps to heat our houses.

Rob Wiblin: Yeah, I see. And hydrogen would be preserved for those situations where you need an incredibly dense store of energy and you can’t get electricity. Or some other reason like that, where electricity isn’t going to be optimal.

Dave Denkenberger: Exactly, like rockets or airplanes.

Rob Wiblin: Right, right, right. Whereas now, because the liquid fuels like oil are the cheapest, we just throw them at everything without needing to worry so much about the cost.

Dave Denkenberger: Exactly. And so basically, even though we could have some part of our economy that is not very good on the energy return on energy invested, it’s a pretty small percent.

Rob Wiblin: Yeah, okay. There was this debate set off by someone who I won’t name who was claiming that in the UK, solar panels didn’t actually return energy — that on net they were energy absorbers. So it’s like basically more energy goes into making the solar panels than they produce over their lifetime. As far as I can tell, this is just completely wrong. It’s just factually wrong.

Rob Wiblin: I mean it could be, probably if you started putting solar panels in like, really northern Norway, or somewhere where the amount of solar radiation hitting the place… I guess it would actually have to be in the Arctic Circle or something. But if you went far enough, this could be true, that the solar panel wouldn’t produce as much electricity as was required to manufacture it.

Rob Wiblin: But in the UK — which is a relatively bad case, not a very sensible place to be sticking solar panels on a global level — they still do produce much more electricity than is required to make them. And I’ll link to a blog post that just demonstrates that this has to be the case, just based on some back-of-the-envelope calculations. Do you have any more thoughts on this energy in, energy out ratio?

Dave Denkenberger: Yeah, so one way you can say that is, they would be extremely expensive if it took so much energy to put in.

Rob Wiblin: Exactly, yeah.

Dave Denkenberger: However, you could say we’re using cheap fossil fuels to make them. So it is true. The other factor here is that if the renewable, sustainable energy is more expensive to begin with, and then you have to multiply it by two, then you’re getting even higher cost. But yeah, if you’re in that case where you need to make the hydrogen fuel, you’d do that in the desert. You don’t do that in the UK.

Rob Wiblin: For sure. Yeah, that would make a ton more sense. So the calculation was saying like, let’s assume that this was using the cheapest electricity that’s available anywhere in China. So it’s using dirt cheap electricity at fossil fuel prices. And let’s say that all of the parts of the solar panel was like energy consumed out of the electricity grid, then like this is how much energy you would get for that.

Rob Wiblin: And we know how much electricity the solar panels actually produce, and the ratio is still high, even taking these very pessimistic assumptions. So that’s one way, at least if the case is clear cut, you can show that you’re getting a positive return. Any more thoughts on energy before we push on?

Dave Denkenberger: I guess people are also worried about the minerals required to make these renewable energy plants. And so they’ll look at wind turbines and say that these generators use these permanent magnets that use rare earth minerals. And that’s true, but it’s also true that with a slight penalty in efficiency, we could use a simple copper coil or even aluminum coil — which is even more abundant — and make these generators. So generally you can just have a small penalty in performance and use something that’s much more abundant.

Rob Wiblin: Yeah. That seems like this is going to be kind of a recurring error that people make in thinking, where they look at exactly how things are done now, when something is abundant. And then they say, “Well, we’re using this thing that currently isn’t that expensive and if it became very expensive then we just couldn’t do it.” And they don’t realize that there’s nearby substitutes that, while somewhat worse at the current price, will be totally viable. And there’s not obviously a supply constraint here with like copper or aluminum as alternatives to these rare earths. Yeah, do you have anything to say about that?

Dave Denkenberger: Right. And the case with copper — people are worried about running out of copper as well. But then I looked at the concentration of aluminum in just regular dirt — it’s higher than copper is in copper ore. So we’re not going to run out of aluminum. Same thing for iron, for steel, and also for cement, for concrete — that’s about 10% of the Earth’s surface. So there are some things that we need a lot of and they’re just super abundant.

Rob Wiblin: Yeah. Where’s the copper going? Isn’t it gone into products that we could potentially grab the copper back from?

Dave Denkenberger: Yeah. So that’s another option. Just more recycling.

Rob Wiblin: Okay. Right. Yeah. I suppose maybe you’d have to dig up the landfills or something, which could be a pain. But in principle, if copper was so valuable, we’d find a way to do it.

Nitrogen and phosphorus [02:03:25]

Rob Wiblin: What about nitrogen and phosphorus, the ones that people often talk about?

Dave Denkenberger: Yeah. So I actually wrote this paper with Joshua Pearce again, looking at nitrogen fertilizer supply that would actually be sustainable. Because right now we take natural gas and we reform it to make the hydrogen, and then we combine it with nitrogen in the air, in the Haber–Bosch Process. But what we said is, in the future, you could use solar energy or wind energy to split water into hydrogen and oxygen, and then use hydrogen with the nitrogen in the air. So that’s fairly straightforward, but you’ll hear people say that once we run out of fossil fuels, we’re not going to have any artificial fertilizers anymore.

Rob Wiblin: Right. The Haber–Bosch Process is very energy intensive, because it’s very energetically expensive to break the bonds in the N2, right? Because it’s a triple covalent bond. I guess that’s still going to be the case if we’re using solar panels or wind. But the thing is, you could make this fertilizer this way using solar panels in a desert somewhere quite remote, and then just ship the nitrogen around, right?

Dave Denkenberger: Right. And we looked at even if you did it locally, you’d take up less than one percent of the land on your farm field, which is much better than not using the fertilizer and then needing twice as much land.

Rob Wiblin: Wow. Hold on. What, okay. That’s amazing. It’s kind of an impossibility proof of this not being viable. You’re saying you’ve got a farm. Let’s say that your nitrogen supplier was completely cut off; you couldn’t get any from elsewhere. Instead, just stick down some solar panels, and attach it to this thing that produces nitrogen. Given what we know about how much sun has to be hitting the plants, that would produce enough energy to produce enough fertilizer, and that it would kind of restore the whole thing and you’d be doing about as well as before.

Dave Denkenberger: Right.

Rob Wiblin: This is so great. Why do people say this is going to be such a big problem?

Dave Denkenberger: I don’t know. I guess they should read the paper!

Rob Wiblin: Okay. Right. We’ll take a look. Do you worry that there could be a mistake with these calculations somehow?

Dave Denkenberger: I think that one is pretty straightforward. I didn’t even think it would be very economical at the small scale of an individual farm. But even that, you could actually scale down the Haber–Bosch Process, which was surprising to me.

Rob Wiblin: All right. Well, I won’t lose any sleep over nitrogen. What about phosphorus?

Dave Denkenberger: Well, phosphorus is an interesting one because people say there’s no substitute, and you have to have phosphorus to grow plants. Which is true. But if you look at the big picture, we could use less phosphorus — for instance, by eating lower on the food chain. Because right now we use so much phosphorus because we’re growing plants to feed to animals. So that would be one simple way of reducing phosphorus consumption. We could also recycle better. We could reclaim it from wastewater.

Rob Wiblin: Yeah. Where is the phosphorus going? Because it’s an element, it doesn’t disappear. It must be just getting embedded into soil or into water or something.

Dave Denkenberger: Yeah. Going in the river and fertilizing seaweed.

Rob Wiblin: I see. Right. Okay. So go on.

Dave Denkenberger: But then we could also just get better at extracting it from the earth. Over the past century, if you look at the cost of minerals — the inflation-adjusted cost, or the real cost — it’s been roughly constant. Which is an amazing feat because we have had to go to lower-concentration ores and we’ve had to go deeper in the ground. But because of technological progress, the cost has remained about constant.

Dave Denkenberger: Now that’s not guaranteed to continue. The energy cost might get higher, like we were talking about, and maybe we just don’t have as much technological progress. But the question is, is this going to cripple us? And so you can look at, of the total cost of food, how much is phosphorus? Even if phosphorus is 10 times as expensive, it hardly affects the price of food.

Rob Wiblin: Right. I guess people grew food before phosphorus fertilizer, right? Because there’s phosphorus in soil. It slows down the growth of the plants to not have added phosphorus, right?

Dave Denkenberger: That’s right.

Rob Wiblin: Okay. Yeah. I guess you’re saying that even if you had to do some very annoying way of getting phosphorous — like trying to pull it out of soil somewhere else — that it would probably still be worth it in terms of the return to food grown, and it wouldn’t even increase the price all that much.

Dave Denkenberger: That’s right.

Energy and food prices [02:07:18]

Rob Wiblin: Okay, Do you have maybe a sociological theory of why people fret about these things, when it seems like some relatively straightforward calculations would show that they’re just not going to be that bad?

Dave Denkenberger: I think one big source of confusion is that people will say how many years’ supply we have of a mineral — say it’s 20 years or 30 years. And they say we’re going to run out. But what does that mean? Well, that’s the reserve — so that means the amount of mineral that we can extract from current mines at current prices with current technology. Well, as we’ve said, technology is generally improving. And even if it doesn’t, if the price goes up, then all of a sudden a lot more resources become economical.

Rob Wiblin: Yeah. so there’s that. And then I guess it’s the substitution issue — which doesn’t apply so much to phosphorus — but it’s like not seeing all of the flexibility in how things could be rearranged in order to… Well, so one flexibility is getting more expensive supplies of these things. And the other thing is just cutting back on your use of them in all kinds of different ways that a business would figure out if the price went up. But it’s not obvious to someone who’s not in farming, doesn’t know about how you could use less phosphorous or use less nitrogen without it being massively inconvenient.

Dave Denkenberger: Yeah. And one thing I didn’t mention: even if the price of electricity goes up a lot — and energy in general — well, then we’d become more energy efficient.

Rob Wiblin: Yeah, for sure. Absolutely. I’m not sure whether you’ve followed this, but we have this energy shortage in the UK at the moment, where the price of electricity has gone up severalfold, and the price of gas has gone up severalfold as well. So it’s going to be a somewhat brutal winter from an energy cost point of view.

Rob Wiblin: It seems like the kind of thing that would ultimately be solved if it stuck around. Like part of the reason why we have this issue is that energy prices aren’t super flexible in terms of what price I’m paying: I’m not paying the full wholesale price — retailers are eating that and some of them are going out of business. But if the price of heating my home went up double or triple on some ongoing basis, people would change all kinds of different things about how they build homes and how much they wear warm clothes at home in order to cut down on those costs. And then that would gradually make the situation less problematic.

Dave Denkenberger: Yeah. So it’ll be interesting to see how it turns out. There was a famous use case actually from my state of Alaska. Juneau, Alaska — the capital — had a cheap hydropower plant, but then there was an avalanche and it cut off the transmission line, so they had to use the backup diesel power. And prices of electricity I think tripled, but people really, really conserved and fast. And the power authority said, it’s going to take us a long time to fix it. But then all of a sudden, when the demand went down, they weren’t making any money, and they fixed it really fast.

Rob Wiblin: Oh, wow. Interesting. Okay. Yeah. Like initially it was in their interest to be charging a lot for the diesel stuff, but then so great was the loss in demand that in fact it was now in their interest to put the hydropower back up.

Dave Denkenberger: Right.

Rob Wiblin: Wow. Fascinating. Okay. What about, I guess your main thing is food, right? So yeah, what about land to grow food, for example? I mean, food I do kind of worry about even in a normal situation, because it’s something we can’t go for very long without. And it does seem like we’re kind of often at the limit of what we can grow in any given year, and we don’t have very long to respond if there’s terrible weather and so on.

Dave Denkenberger: Yeah. So food is much more serious and I kind of think of food and fiber together. I think of fiber as very general — it can mean growing cotton for clothing, but it could also mean growing trees for building buildings and furniture and such. And those are the things that really take up a lot of land and we do need to pay attention to. And it is true that if we had 10 billion people at the US standard of living, these calculations of the ecological footprint — how much land it takes to support your consumption, like an individual’s consumption — you’ll hear these things that if you had 10 billion people at American standard of living, you’d need three Earths or something like that. Which is true at current productivity and yield. And so this is a serious concern.

Dave Denkenberger: I would say maybe the most straightforward is on the wood. In the US, we typically build buildings out of wood, and that takes a lot of land to grow. We don’t have to do that; lots of places don’t build out of wood. But now there’s a movement to build more buildings out of wood, even skyscrapers.

Rob Wiblin: Oh no. Okay.

Dave Denkenberger: Because it is true that the trees, when they’re growing, sequester carbon dioxide. And then even when the building is demolished, if you put it in a landfill where it doesn’t decompose, then that does sequester carbon. So if we are really pushing on climate change, it could be we move more towards wood, and that would use a lot of land.

Rob Wiblin: Yeah. Interesting. So this is one where we really should be paying attention to land use from growing plants potentially. Have you ever looked at over the last 50, 70 years, or I guess actually over hundreds of years, we’ve seen increasing yields. So we get more and more food for any given amount of land. Do you have a sense of in the median case, whether food prices are likely to go up or down in coming decades? Because you’ve got increasing population and you’ve got people eating more meat, which requires more calorie input. On the other hand, you’ve got better technology, like more irrigation, people improving the technology on farms pushing down the price. Do you have a forecast?

Dave Denkenberger: I would say first on the wood side, when I was talking about how minerals haven’t really increased much in inflation-adjusted terms, the big exception was actually timber.

Dave Denkenberger: It’s surprising, right? This is renewable. You wouldn’t expect the renewable resource to get more expensive than your copper, but that’s how it worked out. And I think it’s partly because we may be running into land constraints. But there are some straightforward things to increase the yield from wood production. Right now, we typically don’t apply fertilizers or any pesticides or anything like that. So we could increase the yield.

Rob Wiblin: So if the price of wood went up high enough, then a bunch of things to try to improve yields would then become profit generating, basically?

Dave Denkenberger: Right.

Rob Wiblin: Yeah. Interesting.

Dave Denkenberger: Also, when we cut down a forest for timber, we typically leave a lot of material in the forest. So especially if you’re creating, in the US, we call it a two-by-four: two inches by four inches. Well, the part of the tree that’s not wide enough for that is just left there. But that’s a lot of biomass. That could be turned into something useful: food or fiber or something like that. So I think we’ll get more efficient there as well.

Rob Wiblin: Okay. Makes sense. Yeah. How about food?

Dave Denkenberger: Yeah. So I haven’t put a lot of thought into the near-term forecast. People have observed that in some decades, despite increasing consumption of food, we did not have expansion of planted area because the yield increased. But then in the last couple decades, especially with the growth of biofuels, the planted area has had to increase. And so I’m not sure exactly what’s going to happen.

Dave Denkenberger: I do think that when you hear people say we’ve reached the limit, that’s definitely not the case, because you just look at the variation in yield of the same crop across the world. If you just produce the yield of the Netherlands across the world, you could have two or three times global food production. Now it’s not that simple, of course, because there’s a lot of know-how and inputs that go into that, but it’s certainly technically feasible. And the climate’s even better in the tropics that we’re talking about, so there’s a lot of potential there.

Rob Wiblin: Yeah. So they’re paying a lot of attention to fertilizer, to nutrients, to the soil quality, to irrigating just the right amount, to protecting the plants from pests, and so on. And I guess using the best strains of these different crops is a super big factor. So then here as well, if the price of food reached a really high level, then it could again become economical to apply those kinds of really intensive things and to train people for many years on how to do this extremely intensive, high-tech agriculture in many more places. And that would help to prevent food prices from becoming even higher.

Dave Denkenberger: Yeah. And I think there’s a lot of potential even now at current prices. There was this Green Revolution in Asia where we applied fertilizers, pesticides, improved crop varieties. Many people credit Norman Borlaug with a significant acceleration of that by developing these high-yield varieties. They say he could be credited with saving a billion lives. It’s hard to know the counterfactual there.

Dave Denkenberger: I think that he probably did save a lot of lives, but he also saved a lot of biodiversity, because otherwise we would’ve cut down the rainforest. But he tried to do the same thing in Africa, and he was actually blocked by some environmentalists that didn’t want the use of fertilizers and pesticides and things like that. But to me, it’s not only a win for people, but like I say, it’s a win for biodiversity.

Rob Wiblin: Yeah. Because then people don’t need to farm on as much land and they can let some of it rewild I guess. I think there’s like net rewilding in Europe and the US, and surely the very high crop yields is a part of that.

Rob Wiblin: Okay. What other things do people worry about that maybe they shouldn’t?

Dave Denkenberger: You hear people worrying about landfills. There are media stories about particular waste issues, but it’s a really tiny amount of land. Similarly, mines are a tiny amount of land.

Rob Wiblin: Yeah, I guess landfills are a really fun one. I don’t know how people could imagine that we could run out of land for landfills, because there’s multiple different reasons. One is, we gathered all of this material from the Earth. It didn’t come from space and so we could just stick it back where we found it to begin with. I think in practice, if you’re competent, the landfill ends up, in the fullness of time, using zero land basically.

Rob Wiblin: Because you just dig a big pit, you put all the stuff in it with sufficient sealing in order to prevent anything toxic from leaching out. You have various drainage systems and so on, in order to catch anything that gets out there, and you monitor groundwater. And then I think you concrete it and then you put soil on top of it and then you can just farm on it, basically, as it was before. So a landfill requires land when it’s being filled, but not once it’s full, if you’re doing a state-of-the-art landfill anyway.

Dave Denkenberger: Right.

Rob Wiblin: Okay. Yeah. Is there anything to say on mining and cities? Sometimes people do say, “Yeah, we’re full. There’s not room for people.” Maybe this is the easiest one to reject.

Dave Denkenberger: Yeah, mining is really small. But then there’s the direct living space of people that sometimes people are concerned about. But you look globally and cities are maybe a few percent of the area. There’s possibly a concern that if we go massively to self-driving cars or more extreme telecommuting, that we won’t have as much incentive to agglomerate together. And also if we have automatic lawn maintenance then people might say, “I want a four-hectare lawn.” So then that could be bigger. So that’s a potential scenario.

Rob Wiblin: Okay. Yeah, I guess the lawn mowers must be stopped. I guess at that point then it’s kind of a food issue again, or a wilderness issue — that you are getting rid of wilderness in order to have lawns, or you are displacing farmland or land that otherwise could have been used to keep the price of food and timber low, basically.

Dave Denkenberger: Right. Though one possible way around it is that you could capture your lawn clippings and then feed them to animals.

Rob Wiblin: You’ve always got a suggestion, Dave.

Dave Denkenberger: You can put these things together and you could say, yeah, there’s probably going to be some expansion of people’s living area. Maybe there’s some competition with land area with energy, especially if we do significant biofuels. And then we have the background climate change, which can hurt agricultural yield. And so I do think it’s fairly plausible that food prices will increase significantly. But then I think we’ll move towards resilient foods like seaweed.

Rob Wiblin: Yeah, it is interesting. I feel like, as people can probably sense, I’m skeptical about a lot of these environmental resource sustainability things. But I guess some of them could surprise us. We could end up with various bottlenecks where it’s a big drag to get enough of something, or it’s a big drag to substitute or cut back on our use of it in some way that it’s hard to foresee now. Food does seems like, yeah, it did show up again and again.

Rob Wiblin: In my conversation with Mark Lynas, most of the scenarios where climate change went really badly, it kind of was mediated by food in some way, because it was hard to make a case that anything else could mediate an ongoing collapse other than famine, basically.

Rob Wiblin: So I guess if you’re someone in the audience who is worried about climate change, worried about the environment and resource scarcity in future, I think focusing on improving our resilient access to food, improving our ability to substitute things in disasters, as well as just increasing yields in food seems like it’s a very promising focus area within that worldview.

Dave Denkenberger: Yeah, another thing I would say about the fiber is the fiber for clothing. Again, you have this push for more natural alternatives like cotton. But I don’t think that’s a good idea for a number of reasons. One, there’s a lot of land and water used for cotton production. But in the particular case of clothing, synthetic fibers are more durable, so you can wear your clothing longer. And even if you don’t wear your clothing until it wears out, typically when you donate it, it can go to someone in another country and then they can wear it a long time. The other thing is that synthetic fibers shed water more easily in a washing machine spinning cycle, so then you have less water on the clothing in the dryer and that reduces energy use significantly.

Rob Wiblin: Interesting. Has much been done about the breathability of synthetic fibers? Because I think that was one reason why they went out of fashion; they just didn’t feel so comfortable to wear.

Dave Denkenberger: I think you can get very breathable synthetic fabrics.

Rob Wiblin: Okay, cool. Yeah, most of my clothes for Goodwill are made of cotton, so maybe I should take another look at synthetic fibers. Yeah, it is funny that cotton feels like it should be the more environmentally friendly thing. But I guess you should think of polyester clothes as sequestering carbon kind of — you’re taking fossil fuels out of the ground, turning it into your clothes, and then one day that will go back to the land.

Dave Denkenberger: Yeah, from just a direct use, then at least it’s better than burning the fossil fuel.

Rob Wiblin: Yeah, for sure. It is so funny that very often the thing that feels greener turns out to be worse for the environment. You get this with housing as well, that it seems like living in a cottage in the country would be the green way to live relative to being in a city. But of course apartments in a city are far more energy efficient. Transport is much more efficient when you’re living close together, heating is much better. It’s easier to deliver services to people, logistics is more straightforward. So very often the thing that doesn’t have kind of a green aesthetic turns out to be much, much better in terms of reduced resource use.

Dave Denkenberger: Yeah, and you’ve talked before about this naturalistic bias, I think it’s called, that we tend to think the natural way of doing things is the better way of doing things. But we really need to run the numbers and do that analysis.

Sustainable Seaweed (Sahil joins) [02:21:44]

Rob Wiblin: Cool. I think this is a good moment to maybe bring in Sahil to talk about some of the seaweed stuff, and also what we’ve learned from COVID-19 and the supply disruptions from that. Sound good?

Dave Denkenberger: Sounds great.

Rob Wiblin: Okay. So we’ve just grabbed Sahil. Sahil Shah is a co-founder and director of Sustainable Seaweed, an agritech company scaling seaweed production for food security and blue carbon sinks. He’s also a specialist advisor to ALLFED. Sahil got a first studying economics and management at the University of Cambridge, and among other things since then, he has advised the think tank Let’s Fund, served as a strategy and management consultant with Accenture, co-founded an open source project called the Food Systems Handbook, and is an Action Council Member at the [Atlantic Council](https://www.atlanticcouncil.org/expert/sahil-shah/. Thanks for joining us, Sahil.

Sahil Shah: Thank you so much, Rob.

Rob Wiblin: I’ll just put the same first question that we usually ask all guests to you, Sahil. What are you working on at the moment, and why do you think it’s important?

Sahil Shah: There are two things I’d like to highlight. First is the seaweed. Tim Flannery, the climate scientist, said if we used 9% of the world’s oceans to grow seaweed, we’d produce enough food to feed the world, we’d absorb total global carbon dioxide emissions, and we’d produce enough biomass to meet total global energy demand. On top of that, it’s one of the most promising resilient foods in catastrophes. And I think we are on the cusp of solving a number of engineering and biological breakthroughs to scale seaweed production orders of magnitude higher to what it currently is.

Rob Wiblin: Nice. Yeah. We’ll talk about that in just a second. Was there a second thing?

Sahil Shah: Yes. The second was the work with ALLFED and disaster risk finance. Again, I think it’s a point in timing with both climate change and off the back of the pandemic, where we’re looking to build back better, and we’re seeing a lot more money going to resilient finance. I think by changing the narrative towards tail risk and by being able to better quantify some of the economic and financial impacts of these tail risks — as well as the ability to engineer new types of financial products — I think we have the ability to shift large amounts of funding towards a variety of resilient investments across different tail risks.

Rob Wiblin: Nice. Okay. Yeah, let’s do the first one first. How did you first get into seaweed?

Sahil Shah: Really good question. So I read a book, as I mentioned, called The Atmosphere of Hope by the Australian climate scientist Tim Flannery. I just seemed to be stymied as to why it was so neglected and no one was working on it. There happened to be a European research project that was building out a new set of technologies at the time, which were then looking to significantly reduce the cost of seaweed production through a high amount of mechanization. I reached out to them to basically look to collaborate with them off the back of it, and set up a company and started applying for permits to set up large offshore seaweed farms.

Rob Wiblin: Yeah, we were just talking about some of the advantages of seaweed. Like it grows incredibly quickly, doesn’t require land — I guess it just seems like the main thing it needs is ropes and something to attach them to. Why don’t we use seaweed more? Seaweed seems so lit. What’s the barrier?

Sahil Shah: We use seaweed in some places more than we use it in others. So between 98 and 99% of the world’s seaweed is grown in Southeast and East Asia. And there, people are more used to eating it. There’s a wide number of industrial uses for seaweed as well. Hydrocolloids are extracted from seaweed and are used in everything from toothpaste through to vegan substitutes, as a thickening agent.

Sahil Shah: The main reason we don’t use it so far is because of unit economics and market demand. We’re constantly finding new uses, such as seaweed for flip flops and seaweed clothes. Integrated biorefineries are becoming closer to being cost effective and basically feasible. But one of the big reasons we don’t grow more of it is there are regulatory issues here in the West — especially in Europe and in the US — which means that getting permits takes a number of years. And there are also issues around climate change, where around the tropics the waters are becoming too warm for current species that are grown, leading to impacts on both yield and disease. So it’s a different reason for different parts of the world.

Rob Wiblin: In the UK, for example, if you wanted to grow seaweed, you’d need to get some… I suppose it’s hard to just buy up a piece of the sea, like you can with land. So you need some kind of permit. It’s like setting up a food truck on the side of the street, is that right? You need to get permission to grow it out on what is public waters otherwise?

Sahil Shah: Yes. In short, that’s what you need. However, the oceans are used by a much wider range of actors than we think they are. The seas are used for aggregates, which are then used for concrete, with sand. You’ve got naval uses, fishing uses, recreational uses, and a whole set of others. And the coastline around the UK and most of the European countries is incredibly busy.

Sahil Shah: You also need to have the right type of sea bottom. You need to be at a reasonable water depth. You need sufficient nutrients. And once you start to layer all of these factors on top of each other, you end up with a slightly narrower array of areas in which you can grow seaweed. This is somewhere where I think changing policy to reduce the time and the cost to get these permits could be really transformative in scaling more seaweed.

Rob Wiblin: Yeah. Where in the world is it most promising to grow lots more seaweed? You were saying it’s kind of South Korea, Japan, China? That’s where you might find the most seaweed farms at the moment?

Sahil Shah: It’s mainly China, followed by Indonesia and then South Korea. In terms of where is most promising, China already produces a huge amount of the world’s seaweed, but I think already have targets to produce a significant amount more — both to meet some of their carbon emissions targets, but also to mop up a lot of the ocean waste and the chemical polluters that go out to the sea.

Sahil Shah: Indonesia is particularly promising, just because they already have a large industry, and they also have the ability because of the sheer number of islands to scale that orders of magnitude further. Outside of that, in terms of non-traditional regions, the Pacific and the northern west coast of the US and the west coast of Canada, at least from a climatic standpoint, are particularly well suited. As well as southwest Africa, looking at Namibia and actually South Africa, if you look at nutrient swells as well.

Rob Wiblin: Okay. So that’s kind of another limiting factor — you’ve got to have these nutrient upwellings, unless you’re going to fertilize them, which is maybe a bit difficult if you’re just in the open ocean.

Sahil Shah: You do need to have the nutrient upwellings in some parts of the world. In other parts of the world where there’s a fair amount of intensive agriculture, you already have quite a lot of fertilizer runoff, which gives large amounts of nitrates and phosphates that you would need.

Rob Wiblin: Yeah, and I guess that then it’s an extra benefit that you’re getting rid of those nutrients that might otherwise be polluting. They get sucked up by the seaweed?

Sahil Shah: Yes.

Rob Wiblin: If I were to stumble on a seaweed farm, what would it look like? I guess it’s a bunch of rope attached to a bunch of floating things. Is that the basic idea?

Sahil Shah: It depends how you stumble upon it. If you stumble upon it from above water, all you’ll likely see is a bunch of floating buoys. Otherwise you’ll typically see ropes and some type of mooring system. It can be high tech and low tech — for example, in parts of Indonesia, I think they literally use plastic bottles filled with sand to actually weigh down your system.

Rob Wiblin: Interesting. So your plan is to get more use of seaweed now in the here and now — like actually people buying, people producing seaweed. And I guess that would have the side benefit of being really useful in a catastrophe to have a larger seaweed industry to begin with, because they could mostly continue unaffected post-disaster, and continue making food.

Sahil Shah: Yes. And there’s not just one type of seaweed. There are thousands or tens of thousands of different types of seaweeds. And you may end up in a case where you are producing seaweeds for bioplastics or for biorefineries, or even for textiles. And in the event of a catastrophe, you might repurpose that to produce a different type of seaweed, which could then be used as human food. One of the more promising uses of seaweed is to use it as cattle feed. There’s a particular species called Asparagopsis taxiformis, and certain trials have shown that having it at just 1% of the cow’s diet can reduce their methane emissions between 98 and 99%.

Rob Wiblin: How does it do that?

Sahil Shah: It effectively inhibits particular enzymes within the gut, which means that the cows produce less methane. It’s worth caveating that these trials have only been done over a number of months, so the long-term effects of these are unknown, but look promising so far.

Rob Wiblin: So it’s possible that the bacteria or something could adapt to the seaweed in the diet, and then come back and continue producing methane. But maybe not, maybe it’d be a persistent solution.

Sahil Shah: Yes. Time will tell.

Rob Wiblin: So seaweed sounds pretty great. What are the biggest cons? Are there any downsides of seaweed that people should be aware of?

Sahil Shah: There can be. I guess there are more limitations than there are cons. So although it may be possible to feed people large amounts of seaweed from a dietary standpoint, you do tend to hit bottlenecks in terms of high levels of iodine. You can also have issues when you’re growing seaweed — it can lead to shading off the benthic ecosystem as well. And in terms of nutrients, if there are other organisms competing for nutrients, then it could be negatively affected. However, the negative impacts of seaweed cultivation would likely only be found orders of magnitude higher than we are currently.

Rob Wiblin: Yeah. How much coastline will we need to use, you were saying, in order to feed most of the world with seaweed?

Sahil Shah: It was 9% of the world’s ocean in total. With new types of technology, which increase yield, that’s now probably closer to between 3 and 4%.

Rob Wiblin: Okay. I guess the oceans are pretty huge. So that would end up being like a few percent of all of the land on the Earth basically. Does it need to be close to the coast, or can you potentially do this fairly far offshore in order to expand the area where you can grow it?

Sahil Shah: You can also do this offshore. The benefits of being closer to the coast are, one, you typically have higher levels of nutrients, especially where you have fertilizer runoff. You typically tend to have shallower oceans as well — the deeper the ocean is, the more complex it is to moor the whole system, and often the more expensive it is. And also from a marine standpoint, you need to go quite far out to monitor it, then harvest it and bring it back. Seaweed denatures pretty quickly, and you tend to want to process it within 24 to 36 hours of harvesting it.

Rob Wiblin: Yeah. So seaweed, if you pull it out, it’s kind of a lot of carbohydrate, a bit like a leafy thing, is that right? And could I just pull seaweed out of the sea and then wash it off and then eat it?

Sahil Shah: Some species you definitely could; other species you might need to cook. Some are very high in carbohydrates. Some are high in sugars. There are a couple of very promising species that are quite high in protein. There are two red species, which a startup called Trophic — who are funded by The Good Food Institute — extract proteins from, which are then used in plant-based substitutes for meat or seafood.

Rob Wiblin: Yeah. Okay, what approach is Sustainable Seaweed taking to getting more seaweed out there?

Sahil Shah: We essentially see the problem as one of unit economics. So we are looking at using a high amount of mechanization — both when it comes to seeding and harvesting, developing new types of seeding techniques and purpose-built vessels — as well as trying different types of materials to grow the seaweed on, which can increase yields and improve composition. As well as different types of mooring systems, which would be different to ropes — again, which would have higher yields and higher amounts of mechanization.

Sahil Shah: The main reason why it’s not grown as much in the West as it is in China and Indonesia is to do with cost and price. Seaweed here is generally seen as a luxury good, if you want to buy sea vegetables anywhere. And effectively having something more industrial than artisan means that it would open up a wide variety of new uses that we would be able to then supply to and increase the market as a whole.

Rob Wiblin: I guess seaweed growing so quickly and also not requiring land… Although I suppose you’re saying that the sea is in heavy use as well, so maybe there is competition between other uses — it’s not free territory. But the fact that it grows so quickly makes me wonder why isn’t it cheaper? Why isn’t it competitive with wheat and rice and so on?

Rob Wiblin: And I guess it’s because at the moment, not as much effort has gone into figuring out the absolute cheapest ways to grow tons of seafood, as has gone into figuring out the absolute cheapest way to grow rice and wheat and so on. So if you could mechanize it and industrialize seaweed production to the same extent, then maybe it really could compete on price and it could become a significant source of human calories.

Sahil Shah: Yes, it definitely could. I think another aspect that I would add to that is biological. We don’t understand as much about seaweed as we do about traditional crops. The genes haven’t been sequenced in the same way. We’re not able to manipulate the genome because seaweed can kind of break free and it can move about in the ocean.

Sahil Shah: There’s a very different risk profile of introducing new genetically modified strains. So those are one of the elements where it has been done in China, and actually Chinese seaweed farmers are able to engineer and grow crops that are substantively larger and substantively cheaper. But outside of China, there are regulatory barriers — understandably so — around gene-editing modification, which you don’t have to the same extent on plant-based crops, and which really do contribute to production and cost of production.

Rob Wiblin: Yeah. Yeah. You live in the UK, right?

Sahil Shah: Yes I do.

Rob Wiblin: You’re in London with me. Cool. Yeah. What sorts of regulations would you like to see changed in the UK? Beyond the ones you already alluded to?

Sahil Shah: That’s a really good question. I think there are quite a few. One is that the barrier of proof that there won’t be a negative impact is particularly high. So it can take years and tens of thousands, if not hundreds of thousands of pounds to actually get a seaweed farm in the water.

Rob Wiblin: And I guess it’s a bit unfair inasmuch as like normal farms presumably don’t have to reach quite the same level of proof that they won’t harm anything at all.

Sahil Shah: Yes. The second thing I would add is carbon credits, where some really interesting work has been done, and is being done predominantly by a nonprofit called Oceans 2050. But when seaweed grows, especially the large kelps, up to 50% of the biomass can actually fragment down to the ocean floor, where it effectively becomes long-term sequestered. At the moment, this is very difficult to monitor and track, and there are no carbon credits available. If that were to then change and policy were to change with it, it would suddenly make the unit economics much more attractive.

Rob Wiblin: So when this biomass off the seaweed stays in the ocean, why doesn’t it eventually just break down like other matter, and the carbon go back into the atmosphere? I guess it gets so low in the sea, it basically drops down, such that there’s not very much oxygen, and not many living things down there that would ultimately break it down? So it just kind of sits there?

Sahil Shah: Yes. It drops down to the seabed, which like I say, for the long term is then finally converted.

Rob Wiblin: Converted? So eventually it breaks down, but it’s a very long time.

Sahil Shah: It’s a very long time. Yeah.

Rob Wiblin: Interesting. Is there much more to say on seaweed? Are you looking to hire people for the seaweed project?

Sahil Shah: We will be imminently, so watch this space.

Rob Wiblin: Okay, cool. Yeah. How large is the project and how new is it?

Sahil Shah: It’s fairly large. So we’re in the process of getting our first site here in the UK, which full scale will be enough to produce between 150,000 and 250,000 wet metric tonnes a year of seaweed. We’re hoping to be operational from early next year, and have been going through the permitting process here now for four years, and are in process setting up operations elsewhere in the world too.

Rob Wiblin: Fantastic. Do you want to have a particular resilient food angle? Or is it enough to just be scaling seaweed production in general, and then that has this significant side benefit? That is, all of that infrastructure is sitting there, all of that potential rope-spinning capacity is all awaiting us post–nuclear winter.

Sahil Shah: I think it’s definitely something we have in mind, as well as rope. One of your other limiting factors can be spores and hatcheries. And actually scaling it in particular parts of the world does mean you can have strategic hatcheries that have stockpiles and gametified cultures of particular types of plants, which could then be planted at times of need.

Sahil Shah: So part of it is very much scaling it now, but once we’re able to scale it now, I think it would give us a more nuanced understanding of what the considerations will then be to scale further. I think other parts will be how we then are able to scale further offshore. So once we’re able to scale near shore, and then you want to scale in the deep ocean, you might need to start at floating structures that move within a certain area because you wouldn’t be able to moor a kilometer down to the seabed. So I think as you go through this process and the market grows, you start to learn what the bottlenecks are at increasingly larger orders of magnitude of scale.

Rob Wiblin: Yeah. Have you given much thought to mussels? It seems like they have kind of quite similar properties of being grown on ropes in the ocean. They absorb pollution, I guess they’re pretty nutritious. Maybe underrated as a food?

Sahil Shah: Definitely. And you often have seaweed grown in conjunction with mussels and other shellfish — it’s known as polyculture or integrated multi-trophic aquaculture — and you tend to have a symbiotic relationship, where the waste produced by the shellfish is basically absorbed through into the seaweed and increases the rate at which it grows.

Rob Wiblin: Yeah. Okay. So it’s possible that these things will end up integrated anyway, so not only would you be producing a plant in the sea, maybe you’re also producing this kind of meat substitute or… Well, it is meat because mussels are animals. They’re just hopefully not conscious, or like extremely low-level of consciousness animals. So it’s another potential meat source in a disaster scenario.

Sahil Shah: Yes. Although the work done on colocation is still fairly nascent, so there’s a lot more work that needs to be done before that can be scaled.

Locusts [02:38:33]

Rob Wiblin: All right. Yeah. So I know that, I guess on behalf of ALLFED and maybe other folks, you’ve been paying attention to food security issues around COVID-19. And I know a lot of people — including both of you — are kind of worried that a potential famine could result from disruption to transportation of food and agriculture during the pandemic over the last year and a half.

Rob Wiblin: And actually simultaneously, we had this bad luck of having this terrible locust plague in some various different places in Africa, right? But I’ve heard almost nothing about that in the news for a very long time. So yeah, do you mind giving me and the audience a bit of an update on COVID-19 and food and locusts and so on?

Sahil Shah: Sure. I’ll start with locusts, and then go broader out into COVID and food. We have had the world’s worst locust outbreak in parts of the world for the last 75 years. Locusts swarm under particular conditions — typically triggered by off-season cyclones, when you have the right type of soil moisture, soil temperature and moisture, air temperature, et cetera. And effectively, they’re just grasshoppers, but their serotonin levels change when they reach a particular density, and then they tend to swarm and eat large amounts of food. It’s worth noting that it’s not just been across sub-Saharan Africa, but locust swarms can also reach across the Middle East and even into parts of India and China. So they can threaten the food supply of north of two billion people in the world.

Rob Wiblin: Right. Hold on. So when weather conditions are right, then there’s a potential for locusts to breed an awful lot. And then there’s some behavior change that happens when they realize that they’re at a sufficient concentration of locusts. And maybe that’s an adaptation to the fact that they might run out of food. So they’re like, “I’ve got to grab food really, really quickly, because I’m competing with so many other locusts.” Is that maybe part of the story?

Sahil Shah: Not quite. I think it’s more to do with serotonin changes, which are triggered, and then it informs them to swarm together and bond.

Rob Wiblin: Interesting. What’s swarming as opposed to just normal grasshopper behavior?

Sahil Shah: So normal grasshopper behavior, they tend to be more disparate. Whereas swarming, you literally have sort of large volumes of swarms that you can see visibly, rather than grasshoppers dotted around.

Rob Wiblin: So they prefer to hang out together? Maybe as a way of like, it reduces their risk of being attacked by predators? Because they’re surrounded by other grasshoppers, maybe?

Sahil Shah: Quite possibly. I’m not fully sure on that one.

Rob Wiblin: Maybe thinking back to my biology classes where I learned that lots of animals form herds and lots of birds form flocks, because you really don’t want to be the single… If there’s a lot of birds around, you don’t want to be far away from the other animals, because then you’re easy to pick off by predators. So possibly they’re doing something where they’re like grouping together, because at least to an individual, it offers relative protection against predators.

Rob Wiblin: Okay. Yeah. So we’ve had a terrible locust swarm — this is in Ethiopia, Kenya, where…?

Sahil Shah: Yes. Also spreading out to Yemen, South Sudan, Sudan. I think it went at some point as far south as Uganda, and threatened further west — potentially going as far as Mauritania. And they did go as far east as India and China at the worst point in the outbreak. Swarm sizes can increase up to 20 times every three months, when they lay eggs and then a new set of locusts then appear.

Rob Wiblin: Right. And what impact has this had?

Sahil Shah: It’s difficult to isolate the particular impact that this has had in conjunction with COVID and other natural hazards as well. We’ve seen floods in Kenya as well over the past year and other different weather factors that have impacted yields. But I think we have over 350,000 people now, or close to 350,000 people, in famine in Ethiopia — which is partially due to the conflict, but has been exacerbated by locusts. And we have tens of millions of people in Ethiopia, Kenya, Yemen, and elsewhere who are acute food-insecure, partially as a result of the locust outbreak.

Rob Wiblin: What should be done about this? I suppose an obvious thing is transport food to places where you have locust plagues. Is there much that can be done about the locusts themselves?

Sahil Shah: Yes. So you have control operations to treat locust outbreaks. This involves spraying the locusts themselves — less so when they’re flying, more when they come down to rest at night — and also spraying the eggs that they release as well. These are generally done by planes, and unfortunately, due to COVID-19 and being able to get personnel and planes out, there were a number of delays in actually being able to treat them. This was exacerbated by the fact that a large amount of this was in Yemen, where humanitarian access was particularly challenging, which led to a big delay in resolving the current outbreak.

Rob Wiblin: So I might have intuitively thought that the worst locust plague in 75 years would cause even more damage, that there’d be more visible famines, people just dying and like desperate calls for famine relief. Has that happened and I’ve kind of missed that? Or has this maybe shown that the food supply’s a little bit more resilient to locusts than we might have thought?

Sahil Shah: It’s difficult to know the number of deaths from starvation. I think the malnutrition impacts already have been severe. It’s also worth noting when we’re looking at food crises, it’s very difficult to look at these in isolation. It’s worth noting that there was a degree of success from an appeal through the FAO and food being provided through the World Food Programme and other humanitarian aid.

Sahil Shah: So although the impacts of these and the crop losses were large, luckily at this point in time, there was still sufficient support from the humanitarian community that the effects weren’t as catastrophic as they could have been. However, a worse outbreak that also threatened the west of Africa in a time where it would’ve been harder or less likely for food to have been exported could have led to significantly worse consequences. As well as if operations were less successful in places like the Punjab in India, which is one of the world’s breadbaskets.

The effect of COVID on food supplies [02:44:01]

Rob Wiblin: Yeah. I saw a paper a couple of months ago that was trying to estimate the effect of COVID on extreme poverty and malnutrition. I’ll try to find a link and stick that up in the show notes. The results were much worse than what I thought, given that I hadn’t really heard that much about extreme poverty getting worse because of COVID-19, or all these locusts, or famines or malnutrition — but it seemed like the picture was quite grim, that things had really gotten quite bad in 2020 compared to before.

Sahil Shah: Yeah. And I think it’s important to look at both supply-side factors and demand-side factors. So when we had lockdowns across the world in 2020, you had a large number of people who were already poor suddenly deprived of their livelihoods. And you have stockpiling behavior as well, combined with supply chain fragmentation that led to food price spikes, especially locally. And in some parts of the world, such as Addis Ababa, actually having to enact price ceilings at markets, so food prices didn’t get that high.

Sahil Shah: So a large amount of the issue was also to do with purchasing power, and supply chains as well as production issues. And these aren’t things that necessarily show up straight away, especially as grain stores could be used initially. But when you’re looking at malnutrition, it’s not just about getting enough calories, it’s also about nutrients. And unfortunately when there’s supply chain issues, it’s fresh produce that tends to rot first.

Rob Wiblin: Okay. What about the COVID-19 picture more broadly?

Sahil Shah: Yeah. Again, I’d like to break that down into sort of two or three different factors. I think we saw significant impacts on supply chains initially, and that wasn’t just supply chains of grain, but also agrichemicals, seeds, and getting that transported around the world. You also had issues with ports being closed — there not being enough port workers with ports being sick. And on top of that, we also had export restrictions placed by countries such as Russia.

Sahil Shah: Luckily we saw significantly more international collaboration than we did in the 2007 food price crisis, which meant that food prices didn’t rise as much as they could have done. On top of that, you also had the localized impact in terms of food prices and loss of livelihoods. Understanding the total impact of COVID on global food security is challenging, and I think it most likely will be reflected and seen over time, as we’re able to monitor the malnutrition impacts in different parts of the world.

Rob Wiblin: I’m not sure how quickly FAO statistics come out, but do we know just what was the total calories produced or what was the total amount of food produced, kind of month-by-month during 2020, or maybe part of 2021? So we can just do a comparison and see, was it up or down compared to 2019, say?

Sahil Shah: We have quite a lot of that available through FAOSTAT on an annual basis as opposed to a monthly basis. However, the accuracy of these numbers, especially in a range of developing countries, can be much harder to track as to whether that’s accurate or not.

Rob Wiblin: Yeah. I guess setting aside the accuracy issues for a second, do you know what the numbers were for 2020? Were they reasonable or noticeably down?

Sahil Shah: They weren’t noticeably down. They were down in some parts of the world. However, it’s worth noting that I think weather patterns in high-yield producing parts of the world were able to make up for shortfalls in other parts of the world. And often famines aren’t necessarily brought about by a food production shortfall, but issues around distribution and affordability as well.

Rob Wiblin: Yeah. Were there any cases where the pandemic directly just interfered with transportation of food? Port closures or trucks not available, trains not running? And so people were going hungry just because food couldn’t get into somewhere where previously it was being imported straightforwardly?

Sahil Shah: You had that at a more localized level. You had markets being closed for a prolonged period of time, where farmers didn’t have adequate storage facilities. And since they weren’t able to store their food, that then went to waste rather than being able to be transported to market and then being eaten.

Rob Wiblin: Okay. I suppose a big-picture question that I often have, or that I’ve had about COVID-19 is, what have we learned about the level of cooperation that we might hope for in future disasters? What have we learned about the resilience of supply chains in general, or resilience of supply of the things that people most need, like food? On balance, have we exceeded or fallen below our hopes or expectations before the pandemic?

Sahil Shah: I think we’ve seen international cooperation in some ways, and we haven’t in others. For example, we’ve seen international cooperation when it comes to not enacting food export bans, but we haven’t when it comes to vaccine sharing. We’ve seen it in other aspects of food supply chains — because it’s so globally integrated, there tends to be a vested interest in keeping those running, and in certain countries they can be large exports. It was worth noting that I think at some point Kenyan flower exports, which are particularly important to the country, were down 80% month-on-month in the worst parts of the pandemic.

Sahil Shah: In terms of resilience of supply chains, I think there’s a reason why there’s been a widespread call for having more resilient supply chains rather than everything being as efficient, as important, and just-in-time. And I think we can see with recent policy announcements and especially looking at China’s 2035 and 2050 strategies — I believe to become more self-sufficient in food and their supply chains — as well as calls in the UK, US, and in the EU and other countries to have more self-sufficient supply chains. Singapore’s another interesting example where I think they have their “30 by 30” target, which is to grow 30% of their food by 2030.

Rob Wiblin: Yeah. I guess it’s kind of interesting. I remember in March and April, I was kind of stockpiling food, because I was worried that, even in the UK, a reasonably rich country, it might become difficult to get enough food, or at least the kind of foods that you would want to eat. It seems like that kind of didn’t happen. That at least interestingly, it seems like it’s more challenging now — there’s more things out of stock now in 2021, now that things are kind of returning to normal and people are buying even more than before. But during 2020, at least in rich countries, it seemed like supermarkets remained pretty well stocked, people weren’t going hungry much more than before.

Rob Wiblin: I guess I’m not quite sure what the story is there, but maybe it’s that shipping for the essential stuff was really prioritized, and the government knew that we couldn’t exactly shut down ports to imports of food because that would just lead to absolute catastrophe. So even during the worst parts of the pandemic, essential things like food production and food transport were kept online, and that basically was enough to at least prevent food issues in rich countries like the UK.

Sahil Shah: Yes. At least where there were supply chain disruptions, these were relatively short lived. And because there were enough stockpiles, effectively these could be taken into, so these effects weren’t felt as much. In fact, I think it was the flour mill shutting down, which was the case for the shortages here in the UK, rather than there being a shortage of wheat themselves.

Rob Wiblin: Why did they shut down the mills?

Sahil Shah: I think it was basically due to COVID-19 protocols and ensuring that it was safe to operate.

Rob Wiblin: I see. Yeah. Interesting. I guess I’d hope if we were going super hungry, we’d probably just risk it and keep the mills open.

Sahil Shah: I’m sure. Yes.

How much food prices would spike in a disaster [02:50:46]

Rob Wiblin: So I guess one way of looking at this is trying to estimate how much would food prices spike in the case of various different disasters? I guess something that Dave talks about fairly often is this 10% loss of food or 10% reduction in agricultural output scenario. Do we have any idea how much food prices would go crazy in that kind of situation?

Sahil Shah: It’s worth noting that food prices are complex and the drivers of food price globally are often different to those locally. Back in 2007 to 2009, I think we saw a doubling in the wheat price and a tripling in the rice price, with less than a 2% global shortfall. However, what happened with investor speculation, buyer fuel mandates, and restrictions are what contributed to that increase in global prices. So it wouldn’t be surprising to have a fivefold or even tenfold increase in global food prices if we were to see similar circumstances now.

Sahil Shah: However, those could be caveated; there are other factors as well that influence this — such as how long this shock is for, what the current levels of global grain storage are. So, it’s not a simple answer, but on the tail end of it, you could see potentially five to 10 times increase in current global food prices. And again, that wouldn’t necessarily be geographically proportionate.

Sahil Shah: And a fear of mine is that what we would see in that result is effectively restriction of exports from net producers, and we’ll see rich countries buying up more of the food, and actually those impacts being felt more by poorer countries who — let alone not being able to afford food just due to the nature of international markets — might not be able to place orders in time to be able to import food.

Dave Denkenberger: And those food price increases, we’d be talking about the low-cost food, like grains. It’s not the actual retail price of the average developed country consumer is going to go five times as much.

Rob Wiblin: I see, so this is the commodity price?

Dave Denkenberger: Right.

Sahil Shah: Yes, although that does vary. I think the wheat aspect of a loaf of bread in the UK is roughly about 5% of the price. Whereas for a roti in rural India, it’s closer to 80% of the price. So actually, these elasticities and price increases are felt much more where it’s a greater determinant.

Rob Wiblin: Yeah, interesting. That is unfortunate — that far higher price increase in India potentially than in the UK. I suppose it’s because in the UK you’re mostly paying for the capital of the factory, and the labor, and the retail and so on, which isn’t affected necessarily by bad weather on farms. Whereas in other places, those costs are much more stripped down, and so it’s the price of the real commodity that’s packing most of the punch.

Sahil Shah: Yes, it’s that and the supply chains as well, where often these are bought and then, for example, the flour is then used in the household. As opposed to having a longer supply chain here, where you’ll have wholesaler and then retailer with a markup at each different level.

Rob Wiblin: Yeah, can you explain 2008? People blame the price increase on speculation, but that doesn’t really make any sense as an ultimate explanation. Because if the true amount that people need to pay in order to clear the market in the fullness of time is not going to rise very dramatically, then why would a person speculate that it’s going to go up far more? It seems like that’s a pretty bad deal from a financial trader’s point of view, because they should expect the price to automatically crash down at some point and reach its equilibrium and they’ll be left holding the bag having bought this high-speculated high price increase for wheat or something. I don’t know, it’s never quite made sense to me. It seems like blaming the messenger to some degree.

Sahil Shah: I think it depends upon whether you believe markets are rational. If the effect of market hypothesis holds, then you are definitely right. However, if you believe in Keynes’ animal spirits and the price of something not being what it’s actually worth, but what the average of people think that it’s worth, then you start to see why bubbles occur. And people might speculate just because they’ll make money in the interim rather than actually looking at the underlying value of the asset.

Rob Wiblin: Yeah. Well, if the animal spirits is the issue, that people are irrationally buying it up, hoping to sell it off to someone else at a higher price in the future, then the solution here is to form an investment fund that short sells the price of food during these bubbles — where not only will you suppress the price by selling it, effectively, by borrowing it and selling it — but you’ll also expect to make bank because if you’re correct at picking that this is just a speculative bubble on an important foodstuff, then… I mean, it’s a risky maneuver, but if it is possible to pick that it is animal spirits rather than fundamental price shifts, then it is possible to make money while fixing the problem.

Sahil Shah: It is possible. It is also influenced by policy as well. So for example, if you look at policy on biofuel mandates on crops — such as corn in places like the US — these changes in policy can have huge impacts and price shifts as well. So, it could be possible, but it’s also high risk.

Rob Wiblin: Those fundamental supply and demand things make complete sense to me. Yeah, I don’t know, when people blame finances being fundamental to price formation, I’m always a bit skeptical, because it seems like you can always say that and it’s hard to prove that is not the case. But sorry, Dave, you were going to chime in?

Dave Denkenberger: Yeah, I think it’s helpful to know the context of 2008 because it was also an oil price spike. A lot of people thought, “Oil price… we’re running out. It’s going to keep going up and up and up.” So I think there was speculation involved there. Whereas if you look at the long-run cost of producing oil, people would say, “Well, it’s going to go back to that eventually.”

Rob Wiblin: Yeah. Well, some people presumably did lose a ton of money there because the price absolutely crashed, if I recall, from something like 120 down to like 30. I guess that was partly driven by the financial crisis, then it was later suppressed by shale oil and discoveries of new suppliers and so on. But yeah, I wouldn’t want to have been one of the financiers who was speculating up the price of oil around that time. Seems like a really bad move in retrospect.

Dave Denkenberger: And then if you could, like you say, identify it, then that would be a good time to short it.

Rob Wiblin: Well, yeah, thanks for joining us, Sahil, this has been super fascinating and I think really helpful to the broader conversation that Dave and I are having.

Sahil Shah: Thank you so much.

How Dave helped to save ~$10 billion worth of energy [02:56:33]

Rob Wiblin: We’re almost done. The last time we closed the interview by talking about other ideas that you had been considering other than resilient foods that you thought might have a really huge benefit-to-cost ratio. Is there anything like that you’ve been mulling over in the shower recently?

Dave Denkenberger: I can talk about another project I was involved in. This had to do with battery chargers. And battery chargers, there are tons of different devices, right? Charger for a cell phone, a charger for a golf cart, and all sorts of… And there was this issue of, it’s so many products — how do we regulate the efficiency?

Dave Denkenberger: Of course the first question is, why are they not efficient on their own? And the thing is that most people don’t really know how much energy they use, so there wasn’t really an information campaign that could do this. And so we were looking into an actual energy efficiency regulation. There was no regulation at the federal level in the US, and we were working with the California government, which has been a leader in energy efficiency.

Dave Denkenberger: We found that we could do what’s called a “horizontal regulation,” where the battery chargers in many different products — even though they don’t use very much energy each — there are so many of them that it really adds up. And since there was no regulation and consumers weren’t aware of it, these battery chargers were terribly inefficient. So my team, before I joined, developed a test procedure for the efficiency and they found that in some of these chargers, the energy you got out was 2% of the energy you put in.

Rob Wiblin: Wow, what are they charging?

Dave Denkenberger: This particular case was these batteries like nickel metal hydride and nickel cadmium batteries. They could handle what’s called a trickle charge. Electricity is going into them even when they’re full. And so manufacturers didn’t even put in the simple control circuit to turn the charger off when the battery was full.

Rob Wiblin: Wow.

Dave Denkenberger: They just kept charging it forever. And so that’s how you get these terrible efficiencies.

Rob Wiblin: Interesting. What about laptop chargers? Are we thinking about just external battery chargers, or also just batteries inside all the devices that we use, like phones and so on?

Dave Denkenberger: We were looking at all of them. Fortunately the laptops, because they’re lithium ion, they cannot handle being trickle charged forever, so those had to turn off. But we were able to say we could save tons of energy by using the same technology circuit to turn off all these other battery chargers.

Rob Wiblin: Yeah. So what came of it?

Dave Denkenberger: We developed the test procedure — it’s important to say that the test actually reflects the real-world use — and then tested a bunch of batteries and then figured out why are some more efficient. Obviously you’ve got to turn it off, but there were other things to improve efficiency. And then we proposed an efficiency standard. And what we ended up with would save about a power plant’s worth of energy just in California.

Rob Wiblin: Wow. How many batteries are people charging? How is so much energy being wasted by these things? I would have thought that almost all energy was going to heating and cooling rather than batteries.

Dave Denkenberger: And definitely more energy is going to those, but it was really low-hanging fruit, like I said, because it wasn’t regulated at all.

Rob Wiblin: And so these are just incredibly inefficient?

Dave Denkenberger: Yeah, so it’s things like, not just the obvious laptop, but power tools, electric lawn mowers, personal mobility devices, wheelchairs, golf carts were in there. We didn’t regulate electric vehicles at that point. They were pretty nascent.

Rob Wiblin: Yeah, it’s interesting. With energy efficiency it does seem like a case where just consumer pressure on markets doesn’t work very well because it’s completely invisible to the consumer. Or the amount of effort they’d have to go to to figure out how efficient their charger is… It’s to the level where basically no one does that unless they’re an engineer who has a fascination with this topic.

Dave Denkenberger: Right.

Rob Wiblin: So you can end up spending huge amounts on electricity and have no clue. Which I guess creates this room for just direct regulations potentially being an effective way of dealing with the problem. Did it cost meaningfully more to make the chargers work properly and not waste energy?

Dave Denkenberger: It did cost more, but it was highly cost effective.

Rob Wiblin: Okay. Yeah.

Dave Denkenberger: And interestingly, in this case, if you have a mass-produced product, manufacturers don’t want to have different standards to meet in different states. So once the federal government makes a regulation, the states are preempted from doing a regulation. When I was working on this project, the federal government was proposing a standard. And so it was a race, basically, to get this California standard in place. And I remember the California Energy Commission — we were funded by Pacific Gas and Electric but we were a consulting company — said, “I don’t think we would have made it in time without all your help.” And so we were actually able to get it in place before the federal standard.

Rob Wiblin: And the federal standard was no good?

Dave Denkenberger: The federal standard was very weak. Then we went to the federal government and said, “Okay, hold off. Wait until the California standard takes effect, because it doesn’t take effect right away, and see if it works out and then reevaluate your standard.” And it was very interesting because the energy efficiency advocates are usually like, “Do it as fast as possible.” And the industry is like, “No, take a longer time.” But in this case it was switched: the industry was like, “No, do it right now with this weak standard.” But anyway, we were successful in having them delay, and then it worked out and it was cost effective. And then the federal standard basically harmonized with California, and then we saved a bunch more power plants.

Rob Wiblin: Amazing. When did this happen?

Dave Denkenberger: So the California standard would have been finalized I believe in 2011, and took effect in 2012 or so. And then the federal standard a few years after that. If you look at the total energy saved, we’re talking on the order of $10 billion, even if we were just looking for the seven-year cycle — because the Department of Energy in the US reviews their efficiency standards every seven years, so they could have caught it later.

Rob Wiblin: Are there other products that people should be analyzing? It seems in this case like the absolute size of the benefit is quite large and the benefit-to-cost ratio is enormous. It’s extremely worth doing. Are there other places that people should maybe be looking for where energy efficiency standards are too lax or completely lacking?

Dave Denkenberger: I think that finding a product that has no regulation is going to be the lowest-hanging fruit, and there are still ones out there. For instance, I’ve done a bunch of work on laundry equipment. And there’s a federal standard for clothes washers, and clothes dryers, and a partial one for some commercial clothes washers — but no commercial clothes dryers and no big commercial clothes washers. So that, I think, is really low-hanging fruit.

Rob Wiblin: Interesting. Yeah, maybe somebody in the audience can go and look at that.

What it’s like to live in Alaska [03:03:18]

Rob Wiblin: All right. Actually the final question now. You live in Alaska, which is an interesting place to live, and not a place that a lot of people I know live. What’s it like up there?

Dave Denkenberger: Well, it’s certainly an adventure in Fairbanks. It often gets to -40 degrees Celsius, and that is the same as -40 degrees Fahrenheit. It’s so cold that salt doesn’t work on the roads, so our roads are covered with snow for about five months a year. Recess for my kids goes down to -19 degrees Fahrenheit or -28 degrees Celsius. They huddle together like penguins. Actually, they tell me they just run around a lot. One other thing in particular about Fairbanks is it’s 65 degrees latitude, so it’s very close to the Arctic Circle. And so that means at the winter solstice, the sun only peeks above the horizon by about one degree and only for four hours.

Rob Wiblin: So it’s like a perpetual sunset, kind of?

Dave Denkenberger: Right. Another thing is that 75% of the communities in Alaska actually have no road access. Now that’s not 75% of the population, but you have all these remote communities. They are typically on the coast, so they are serviced by barges. Though there are some communities that are just only serviced by airplane. And then interestingly, Juneau, from the energy efficiency story, is the capital of the state of Alaska. It also has no road access. So they say there are only three ways of getting to Juneau, and that is by boat, by airplane, or by birth canal.

Dave Denkenberger: Another interesting thing with Alaska is that COVID was delayed and yet we locked down at about the same time as other places in the US, so that meant that it was basically suppressed in the summer of 2020. We also had the fastest rollout of the vaccine of any state, which was really surprising to me with these remote communities. And one of the nice stories was there was a batch of 10 COVID vaccines that had to be used at the same time, but the village was so small that you only had six people that actually wanted to be vaccinated. But at that point, vaccines were really scarce, so they decided to fly the people from the remote community to a hub town, so that they could utilize the vaccines well.

Rob Wiblin: Without wasting the other five, I guess?

Dave Denkenberger: Right. But then unfortunately with all this delay, our vaccination rate is not very good now. We’ve actually experienced the worst part of COVID in October of 2021.

Rob Wiblin: It feels very ridiculous, and yeah, it’s unfortunate.

Dave Denkenberger: Yeah.

Rob Wiblin: What is there to do for fun up in Alaska? I’m not very outdoorsy, so I’m guessing that the things won’t appeal to me that much, but maybe to other listeners.

Dave Denkenberger: I’m big on hiking and have been for a while. And I have a spreadsheet of all my hikes that chronicles not just the horizontal distance, but also the vertical distance. And especially when I was in Colorado, my goal was to do the vertical gain and loss of the equivalent of going from sea level to the top of Mount Everest and back each year. And I made it most of the years.

Rob Wiblin: Wow, that’s so cool. Nice. How difficult is that? How many hours are we talking?

Dave Denkenberger: It was really only a few hours a week.

Rob Wiblin: Yeah, I guess a few hours a week adds up over time. What is that, like 150 hours to walk to the top of Mount Everest? Yes, I guess that kind of makes sense. I suppose it depends how steep it is. I guess if it’s a sheer cliff it could take longer.

Rob Wiblin: Cool. Well, yeah. Thanks for everything you’re doing with ALLFED. It sounds like you’ve been super busy the last couple of years, and it seems like it’s bearing a lot of fruit. Maybe we can check in in a couple of years’ time and hopefully you’ll be able to talk about one of these things being actually scaled up to a factory and seeing how much food you can make. And maybe you’ll have had the chance to eat some of it.

Dave Denkenberger: Yeah. Thanks so much for having me again.

Rob Wiblin: My guest today has been Dave Denkenberger. Thanks so much for coming back on the 80,000 Hours Podcast, Dave.

Dave Denkenberger: Thanks, Rob.

Rob’s outro [03:06:58]

Just a reminder that Dave and ALLFED are fundraising at the moment in order to be able to pursue more of the lines of research covered in today’s episode. If you’d like to donate, which I think is a very reasonable decision, then head to ALLFED.info/donate or contact David at [email protected] They accept crypto and can offer tax deductibility in a wide range of countries.

If you’re listening to this the day of release then Giving Tuesday is tomorrow November 30 and you can potentially get your donation matched at 8 AM US Eastern Standard Time. Learn more about how that works at www.eagivingtuesday.org.

ALLFED is also hiring for four roles as I record this — Project Manager, Project Coordinator, Senior PA and CRDM administrator — you can check out jobs at ALLFED.info

If you’d like to hear more from Dave you can head back to episode #50 – Dr David Denkenberger on how to feed all 8b people through an asteroid/nuclear winter.

We cover the obvious, but also some critiques of ALLFED’s strategy, whether we should leave guides to producing resilient foods in cities all over the world, and other engineering proposals for improving the world from Dave, including how to prevent a supervolcano explosion.

Alright, the 80,000 Hours Podcast is produced and edited by Keiran Harris.

Audio mastering and technical editing by Ben Cordell.

Full transcripts and an extensive collection of links to learn more are available on our site and put together by Katy Moore.

Thanks for joining, talk to you again soon.

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About the show

The 80,000 Hours Podcast features unusually in-depth conversations about the world’s most pressing problems and how you can use your career to solve them. We invite guests pursuing a wide range of career paths - from academics and activists to entrepreneurs and policymakers — to analyse the case for and against working on different issues and which approaches are best for solving them.

The 80,000 Hours Podcast is produced and edited by Keiran Harris. Get in touch with feedback or guest suggestions by emailing [email protected]

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