After doing a bit of digging, I'm pretty convinced that nuclear famine was never a thing to begin with. Maybe back during the Cold War, when the Soviets were seriously considering ground-bursting thousands of warheads across the American corn belt to knock out missile silos, but that's not the world we live in anymore. With modern C&C , they simply can't realistically expect to destroy those sites before launch. I've heard Peter Zaihan and alarmists say things like "the world only has 2 months' worth of food in reserve" and assumed they were right, but the numbers say otherwise. For this analysis, I'm using this USDA report

This is dried grain stored across the United States. Soon, after the autumn harvest, the US will have more than 400 million tons of dried grains in storage. They range from 3000-4000 kcal per kg. Assuming an average daily consumption of 2000 kcal per person per day and a population of 330 million, that's around half a decade's worth of food from this stockpile alone. Most of it goes to animal feed/ethanol under normal circumstances. Even a worst-case scenario in September still gives a 90 million-ton stockpile, which is enough to feed America for more than a year. And at that point the grain is in the field, almost ready for harvest. This isn't an emergency stockpile, it's just what farmers have lying around to arbitrage against harvest-related price fluctuations. There are also plenty of other foodstuffs in the American food supply chain, stockpiles of other foods, the FEMA food stockpile, and so on, but it is pretty incredible most analyses of nuclear famine don't take even this into account. At this point, I'm convinced the entire field is based on active misrepresentations for anti-nuclear messaging and was never at any point interested in honest inquiry. 

The nuclear famine paper I analyzed earlier lied about this, by the way, implying that existing food stockpiles would only increase food availability in the first year. I am awestruck that this isn't more well-known when people talk about casualty projections from nuclear war.


Addendum: Denkenberger posted two papers he wrote in regards to a 150Tg nuclear exchange scenario (worst case scenario, total targeting of cities). As far as I can tell, although the developed world doesn't come close to famine and there is theoretically enough food to feed everyone on Earth, the increase in food prices can cause large-scale famine in developing countries in the absence of international aid.

Correction: Denkenberger posted two papers he wrote in regards to a 150Tg nuclear exchange scenario (worst case scenario, total targeting of cities). Feeding everyone on Earth is possible, assuming massive scaling up of resilient foods (requires more planning and piloting to be likely) and continued international trade (uncertain). I agree that food/fertilizer/fossil fuel export bans may well occur after a nuclear exchange.

New Comment
37 comments, sorted by Click to highlight new comments since:

Sorry for the short response here, hopefully when I have time later I can expand on it.

Background: Read your posts, not the paper

Main Point of disagreement - Famine is not about stockpiling or even producing the requisite calories. It is about distributing the food from where it is produced (or stored) to the population centers where it is needed. With grain transport most of it is done via rail with major exchange centers and logistics hubs being cities. In a nuclear exchange this infrastructure is completely wiped out (both the human capital and the actual physical structures).

To be blunt, of course no city>no people>who starves? Thus the famine is averted because the mothers/father/daughter/sons have all been wiped out in the blast right? Well the loss of all this logistics infrastructure means that suddenly rural people in non-productive (agriculturally) areas who escaped the blast also starve. Most critically here is that this is in fact a large swaths of America. (tangential point): This is within only the first few months following the exchange; imagine needing to further plant a new year of crops w/o easily accessible fertilizer/pesticides/herbicides and fuel (both diesel and nat gas- that corn ain't gonna dry itself). The USA is perhaps the most prepared of any country with it decades long transfer from rail to trucking, but as a country it is still far far away from being able to have a distributed logistic system in the form of trucking that could manage in the absence of rail (without taking into account the other issues a nuclear attack would cause).

Regarding distribution, there's also the potential to permanently knock out our electronics and power grid with a high-altitude detonation and resultant EMP waves:

If you knock out the solenoids in all our vehicles as well as the power grid and other electronics, it will be very hard to move that stored food anywhere, and most people will probably starve.

Knocking out rail infrastructure for months doesn't seem plausible to me. Rail is made of hardened steel. Short of being inside the fireball, I don't see how it would be damaged beyond repair. Maybe rail stations can be targeted, but that's still a tiny proportion of the rail that exists in the US. Less-used tracks can be cannibalized and machine shops can probably produce short-term replacement rail to keep critical lines running. 

As for fossil fuels, I am unsure of how much they will be targeted, but each warhead that hits an oil rig is one that's not hitting a city. In addition, the majority of the world's fossil fuel production is outside of the US and Russia, and won't be targeted. A major concern is probably oil refineries, which are very concentrated in the US, Russia, and China, but the distillation of crude oil is actually mechanically quite simple, requiring only a heat source and a condenser - you can theoretically build one in your back yard, and people have. The main reason modern refineries are so expensive and time-consuming to build is their heavy focus on efficiency and safety.

Also, there's the beating heart of American agriculture, the Mississippi River. It branches throughout the Midwest, going all the way up to the Great Lakes. The considerable majority of American people and agriculture are located within a hundred km of either it or the ocean, meaning distribution would be relatively easy, even if land transportation is heavily disabled.

I am unsure about fertilizer and pesticide production, especially in the case of fertilizer export bans by other nations. I think it depends heavily on how well American natural gas production survives, but lack detailed knowledge.

First lets constrain this conversation a bit- let's only look at the US and the likelihood of famine occurring there (as we have already been talking about it). Secondly I think we can both agree that the result this is heavily dependent on the type of strike, how may cities are actually lost and the surrounding context of the exchange (is the US and Russia/China at war), but for the sake of the conversation lets say that the US immediately won the prevailing conflict and doesn't have to concern itself with preforming or dealing additional military operations. So which cities are mostly likely targeted? One needn't look far to see that targeting logistic hubs is fairly high on the list of likely enemy action (1, 2) following close behind domestic nuclear facilities and military targets. It is hard to say but perhaps we can go with a few dozen of Americas top cities were targeted along with a few Nebraskan wheat fields and military bases (it seems to me this is the scenario that most in this thread have been talking about).

Okay, with that context lets revisit the initial problem area- what does the logistics chain of bulk commodities following a nuclear exchange look like? Firstly, I invite you to take a look at this map of US rail lines (note that this does not include all rail connections- I'm assuming spurs and private lines are not shown). Notice many of the large intersection points are in large cities which are very likely to be hit (also most of these rail yards are actually very close to the city center where fireball damage would occur). As you say most of the rail lines outside cities would likely avoid significant damage, however most of the important logistics infrastructure lies within the rail yards this includes the rolling stock, offloading equipment, signaling/coordinating structures, and arguably the most important the human capital- would all be destroyed. Yes, other less important or used track could be cannibalized for use and various surviving heavy machine shops somehow forced into helping with the reconstruction efforts, I am left a bit skeptical how they get a bunch of workers (who maybe just lost everything in a blast) to go clear, sort debris, re-lay track and signaling, and learn how to operate the whole system all within inside a highly radioactive zone.

I digress though, thank you for bringing up the inland water ways- I think this is one of the best reasons the US could weather intentional logistics damage the best. However I will again point out that the limited barge stock available, and particularly where the largest inland parts are located- again in large cities that would likely be targeted.

From a meta point of view, the key thing to remember here is not what is theoretically possible but what is likely using previous experience, to happen. As an example - theoretically yes, someone with access to crude oil, some metal stock, and a small amount of equipment could make a very rudimentary oil distillation system but why would they do that? I get that you originally used it just to illustrate how basic some industrial processes are (which I don't know if I really agree), but missing in your thought process is the 'why?' or 'who?' would do all of this. Logistics is Coordination and coordination is hard. Sidenote: Martial Law or at minimum a nationwide state of emergency would likely be declared in such an event likely simplifying decision making and coordination. However, how quickly this could be ramped up to nationwide scale following significant damage to communication systems I will leave unassessed.

I would recommend reading about the supply chain issues that have been caused by COVID and the ongoing Ukrainian War, and just extrapolate out. I realize that because we are discussing famine it narrows the scope of what we are concerned about (ie only moving food from A to B) and with a short time horizon, the issue is still surprisingly complex.

My apologies if my line of reasoning may have been hard to follow at the end let me know if there is anything you find unclear.

I think what the two of you have identified is that the hardiness of logistics and coordination capacity seems like a key determinant of how well we'd weather a nuclear exchange. If it's robust, some combination of stores and agricultural adjustments could allow us to avoid famine. If it's weak, we might experience famine even if there's plenty of siloed food.

The results of the original paper could be taken, then, as a proxy for the "logistics failure" scenario. What limited food we can access lasts us for about a year, and our practical ability to adjust our agricultural practices is minimal for one reason or another. It's not couched in those terms, but it represents them.

I think publications considering outcomes under a range of logistics scenarios, as well as modeling the impact on logistics capacity itself, would be very valuable. My advice is that, while it's natural to be angry about academic shortcomings on an important topic, it's helpful to be collegial. If anyone here is hoping to produce any of this research, it is probably not a good long-term strategy to start by accusing your future colleagues of "lying," short of a flat-out deliberate misrepresentation of current, verifiable facts as opposed to a contentious choice of predictive modeling assumptions.

The nuclear famine paper I analyzed earlier lied about this

I think it pays to have a higher bar for calling something a "lie". The paper does explicitly state their assumption that stores last only one year. You provide good evidence that this is a bad assumption, and it's possible that it was made in bad faith (i.e. the authors maybe knew it was a bad assumption), but I think calling it a lie based on current evidence causes more heat than light.

It actually is that bad. If that was the sketchy thing in the paper, I would have given them the benefit of the doubt, but it wasn't. So many basic assumptions, like land under cultivation, which crops were planted where, ect., were bad. If you read a paper that concluded 99% of people in a building will die in case of a fire without fire alarms, because an assumption of the simulation was that people will continue to sleep while they are on fire, that's not an honest mistake. That's something a fifth grader can point out is nonsensical. Whoever wrote that is not acting in good faith.

If this was published in a low-impact journal or written by a first-time author, I would have ignored it as publication pressure induced padding. But the people who wrote it are good scientists. The primary author did a bunch of well-regarded models with aerosol modeling. Most importantly, Nature should have noticed something was wrong immediately. Everyone involved should have known better. 


Did the papers offer underlying rationales for their assumptions? For instances, due to power disruptions much more grain would be lost to rot due to poor storage conditions? Or perhaps speak to how much of the stock might be too irradiated for consumption? Or transportation issues?

I wonder about your fire example as well. Dismissing the claim that most/nearly all will sleep through a fire is so nonsensical that even a 5th grader can see through it seems questionable. Fires do consume oxygen and low levels of oxygen do put people to sleep -- or make them very drowsy -- so suggesting people people might be expected to continue sleeping, and perhaps fall into a deeper sleep, seems to need a stronger argument than a 5th grader doesn't accept that claim.

No rationale was given for their assumptions. It wasn't even analyzed. There were no justifications, just single-sentence statements for what assumptions they used. There's a big difference between "some people die to fires in their sleep", which makes a lot of sense, and "99% of people asleep during a fire die", which would require extremely good justification as an assumption in a simulation. You can't just put that in a paper with no analysis.

This was published in Nature. I've seen papers get rejected from impact factor 1 journals for less. 

Strongly upvoted for giving a reasonable comparable example.

I would agree in regards to the example of a building fire. If a group of very respected folks published a paper about the consequences of building fires, etc., with an assumption that nearly everyone will continue to sleep while on fire, that would seem to be ridiculous. And probably would be perceived as being made in bad faith, if clearly enumerated and not hidden away.

It's somewhat disturbing that the editors at Nature would allow this through, it raises the question of what other absurd assumptions they allow in 'impactful' papers.

Assuming an average daily consumption of 2000 kcal per person per day and a population of 330 million, that's around half a decade's worth of food from this stockpile alone.

And that 330 million number is likely to decrease significantly after a nuclear exchange sufficient to cause nuclear winter, so half a decade is likely a lower bound.

Nitpick: US per-capita calorie consumption is 3782kcal/person/d (source). Some of that is waste and pet food which can be reduced in a disaster scenario, but most of it isn't. Use of 2000kcal/d as a placeholder number for typical dietary intake is a pet peeve of mine; for most adults, 2000kcal/d is a mild weight-loss diet. A lot of people get tripped up by this when they first start trying to quantify their intake, and falsely assume that the 2000kcal/d number is typical and normative when in fact none of the careful sources are using it that way. (Actual needs vary based on height, activity level, age, weight, and other factors; the way to get a real estimate for the calorie requirements of a specific adult is to use the Harris-Benedict equation to get a BMR and multiply it by an activity factor.)

I might think daily expenditure per person could even increase after a large scale nuclear war as more people need to engage in more physical labor.

If anyone would like to be funded to do actual high quality research on this topic, I strongly encourage application to FLI's Humanitarian Impacts of Nuclear War grant program. For decades there have been barely any careful studies because there is barely any research funding or support. It's quite possible the effects are not as bad as currently predicted, but it's quite possible they are worse — the modern nuclear winter studies fund that things are worse than the early ones in the 80s (though fortunately the arsenals are much smaller now.)

It seems quite important to me to have a clear-eyed view of what the results of "small" and "large" nuclear wars are like. An all-out nuclear war between the US and Russia currently would probably involve of order 1900 warheads on each side, which is still a stupendous number. (See the BAAS's nuclear notebook for some pretty detailed arsenal numbers.) If something starts, I'm deeply pessimistic about a maintaining a "limited" nuclear war between these two, much as I'd like to believe otherwise.

Maybe back during the Cold War, when the Soviets were seriously considering ground-bursting thousands of warheads across the American corn belt to knock out missile silos, but that's not the world we live in anymore. With modern C&C , they simply can't realistically expect to destroy those sites before launch.


Can you link me to any sources or other analysis backing up the idea that silos wouldn't be targeted in a modern-day US/Russia nuclear exchange?  (I would suspect that, even if the optimal strategy may have changed, outdated Russian nuclear-war plans might not have been updated!)  Since I live in Fort Collins, Colorado, around 40 miles from the hundreds of ICBM silos of the Pawnee National Grassland area, this esoteric issue of "nuclear sponge" strategy is very close to my heart!

40 miles away, the only way the explosions can badly hurt you is via fallout. It is relatively easy for informed people with, say, 72 hours of warning of the attack to protect themselves from fallout. They will be spending most of those 72 hours digging a trench, topping the trench with plywood or felled trees or such, heaping about 18 inches (maybe make it 24 inches for people in your situation) of dirt on top of that wood, then putting a sheet of plastic on top of that so that rain cannot wash the fallout into the trench.

If the fallout is very heavy, you have to stay in the trench/tunnel for 3 weeks. You can venture out for an hour after week one to scrounge for supplies if you want.

You can make the trench/tunnel in the yard of your home if you have a yard. In contrast, the only way for residents of, e.g., Berkeley, Manhattan or San Francisco to protect themselves that doesn't involve hiring an expert and probably spending 100s of 1000s of dollars and many weeks of warning of the attack is to move themselves many miles away from their home before the start of the attack.

The really ugly aspect of the situation is that if you've prepared by digging yourself a fallout shelter and stocking it with food and water, you have to deal somehow with desperate unprepared people -- great numbers of them if you're in the wrong place. That is why, e.g., Switzerland made sure that everyone would be prepared, by having communal fallout shelters in its cities and requiring home owners outside the city to maintain fallout shelters in their homes, but even Switzerland stopping doing that after the end of the Cold War.

Nuclear famine (and relatedly nuclear winter) is one of those things that comes up all the time in discussion about existential and catastrophic risk, and this post (together with the previous one) continues to be one of the things I reference most frequently when that topic comes up.

Very surprised by this! I wrote this at work while waiting for code to run and didn't give it too much thought. Didn't expect it to get this much traction.

Nuclear winter/nuclear famine being fake is something I've suspected for awhile (without specifics, eg I never looked into the size of food commodity stockpiles.) I avoided talking about it partially because it seems infohazardous; "a nuclear war reliably inflicts famine on the victor" seems a lot like a noble lie that someone might spread to reorient militaries away from starting one.

I'm confused about how to relate to this, because I still think any nuclear exchange would be catastrophic for everyone (including the victor, and even assuming that use-nukes-to-shoot-down-other-nukes tactics work as intended). But, even if it's good for everyone to be deceived about this from a nuclear-risk perspective, I think the collateral epistemic damage is bad enough that we shouldn't have noble lies in this area; people need to know the truth about how resilient or how brittle the food supply really is, in order to be able to evaluate other risks like climate change or supervolcanoes.

Denkenberger posted two papers he wrote in regards to a 150Tg nuclear exchange scenario (worst case scenario, total targeting of cities). As far as I can tell, although the developed world doesn't come close to famine and there is theoretically enough food to feed everyone on Earth

To clarify, the world would have enough food if trade continues and if we massively scale up resilient foods. Trade continuing is very uncertain, and making it likely that we scale up resilient foods would require significantly more planning and piloting. 

I'll correct it after I get off work and do a bit more research. Do you know where I can find the projections for a "nuclear war tomorrow" scenario? What is the contingency for ALLFED if it actually happens?

 These posts discuss response.

Does anyone know of any zero-trust investigations on nuclear risk done in the EA/Rationalist community? Open phil has funded nuclear work, so they probably have an analysis somewhere that concluded it is a serious risk to civilization, but I haven't ever looked into these analyses.

ALLFED has been doing research recently into nuclear winter. This seems to be their most relevant publication so far. I haven't read it yet.

Thanks, Peter. That draft assumes global cooperation, which is likely too optimistic, so we have submitted another draft that also analyzes the case of breakdown of trade (hopefully public soon). We also have this paper that looks at the US specifically and takes into account food storage (and uncertainty of whether nuclear war would result in nuclear winter).

I was looking for exactly something like this! Thanks for posting. How were these two papers received in your field? 

For the one paper, it is too early to tell. For the other, there just has not been very much engagement. Mainly the public debate has been between the Robock team, which is highly confident that full-scale nuclear war would cause nuclear winter, and the Los Alamos team, which is highly confident that full-scale nuclear war would not cause nuclear winter. We find the truth is likely somewhere in between. I talked about this in one of my 80k podcasts. Our analysis is quite similar to Luisa Rodriguez' analysis that cubefox links to below.

Would it be possible for you to make a post with a brief summary of what you expect to happen in a nuclear exchange? I think a lot of people would be interested in something like that given the recent talk about the possibility of nuclear war from the Russia-Ukraine war.

Skimming the methodology it seems to be a definite improvement and does tackle the short-comings mentioned in the original post to some degree at least.

Yeah apparently the nuclear winter story was actively promoted by Soviet spies

Unclear to me if this piece of Soviet propaganda was on net bad or good for preventing nuclear brinkmanship.

It seems the abstract of the study you link does not mention spies?

A recent discussion of this with one of my sons brought up the question of essential nutrients as simple as salt. Our guess was that local stores of these have long been depleted and today might be sourced from.far away optimized locations. Could be a bigger problem than grains that grow everywhere.

Thanks for the content. 

I woke up today wondering about fallout. Wich modern, mostly fusion weapons, it surely cannot be that bad. 

The amount of grams of plutonium used before detonating the fusion reaction should be too little to generate the mass histery about fall out, this is not the sixties. 


Epistemic status: I only have hunches and have to confirm what I just wrote with facts. 

For what it's worth, most modern fusion bombs actually generate most (e.g. 80%+) of their "yield" from fission - the fusion stage is surrounded by a layer of uranium which is bombarded by neutrons produced in the fusion reaction, causing fission in the uranium and magnifying the yield. So they are pretty dirty weapons. They are at least smaller than the weapons from the 50s and 60s though.

Fusion bombs don't produce much fallout from airbursts - the worry of fallout is the large-scale use of ground-burst bombs designed to target hardened facilities like bunkers and missile silos. Dirt would then absorb much of the resulting radiation, become radioactive, and get carried by wind.

And you're welcome for reading :^).