Possible way of reducing great power war probability? 2019-11-28T04:27:19.768Z
Americans give ~4%, not 2% 2019-11-03T19:10:13.012Z
Remote local group leaders? 2019-10-13T21:43:20.814Z
David Denkenberger: Loss of Industrial Civilization and Recovery (Workshop) 2019-02-19T15:58:01.214Z
Alliance to Feed the Earth in Disasters (ALLFED) Progress Report & Giving Tuesday Appeal 2018-11-21T05:20:37.922Z
Cost-Effectiveness of Foods for Global Catastrophes: Even Better than Before? 2018-11-19T21:57:05.518Z
[Paper] Interventions that May Prevent or Mollify Supervolcanic Eruptions 2018-01-15T21:46:27.407Z
How you can save expected lives for $0.20-$400 each and reduce X risk 2017-11-27T02:23:44.742Z
Should we be spending no less on alternate foods than AI now? 2017-10-29T23:28:39.440Z
Futures of altruism special issue? 2016-12-18T19:16:02.114Z
Saving expected lives at $10 apiece? 2016-12-14T15:38:38.561Z
Advice Wanted on Expanding an EA Project 2016-04-23T23:20:02.455Z
Essay Competition on Preparation for Global Food Catastrophes 2016-03-17T01:49:12.131Z
Investment opportunity for the risk neutral 2016-01-25T15:29:48.579Z
My Cause Selection: Dave Denkenberger 2015-08-16T15:06:25.456Z


Comment by Denkenberger on Great Power Conflict · 2021-09-22T06:44:38.732Z · EA · GW

From the same reference, twelve out of 16 times that there has been a switch in which is the most militarily powerful country in the world, there has been war (though one should not take that literally for the current situation). China will likely become the most powerful (economically at least) in the next few decades, unless the US allows a lot more immigration.

Comment by Denkenberger on [deleted post] 2021-09-11T02:50:00.474Z

They have started work, but I'm not aware of any publications yet.

Comment by Denkenberger on [deleted post] 2021-09-11T02:49:04.112Z

Thanks to Pablo for letting me know about this discussion. We were using alternate, but that had a different definition in Australian English, so we switch to alternative. But then we saw that there is an official definition of "alternative food" here. So we think resilient food is the best. We are going to be releasing a new version of our website with resilient food, and we have already switched our papers under review to resilient food.

Comment by Denkenberger on [Paper] Interventions that May Prevent or Mollify Supervolcanic Eruptions · 2021-09-10T22:21:36.128Z · EA · GW

Thanks! Those are good questions. I have not put any more effort into it because resilient foods are likely lower cost to prepare for and protect against multiple catastrophes including super-volcanic eruptions. However, if we can get a few hundred million dollars for resilient foods, maybe working on preventing super-volcanic eruptions will be next on the list…

Comment by Denkenberger on Neglected biodiversity protection by EA. · 2021-09-06T17:59:52.953Z · EA · GW

I think the first dot point deserves fleshing out. I have done a very preliminary analysis of getting prepared with resilient foods for agricultural catastrophes such as nuclear winter, and it appears that this is a very cost-effective way of saving species. This is because if many people were starving, not only would they generally not care about preventing other species from going extinct due to the climate impacts, but they would likely actively eat many species to extinction. It would not take that much more work to turn this into an actual paper, and ALLFED would be happy to do it if someone wanted to fund it specifically (~$20,000). The model also has AGI safety, so we could look at the cost-effectiveness of that work of saving species. Naïvely, one might argue that preventing human extinction from a pandemic would be bad for biodiversity. However, the only hope of biodiversity continuing beyond about a billion years when the earth would naturally get too hot would be humans controlling the climate or relocating species. So overall, I would agree that work on existential risk is likely effectively helping biodiversity in the long term.

Comment by Denkenberger on Linch's Shortform · 2021-09-06T17:49:25.996Z · EA · GW

I think it would be valuable to see quantitative estimates of more problem areas and interventions. My order of magnitude estimate would be that if one is considering spending $10,000-$100,000, one should do a simple scale, neglectedness, and tractability analysis. But if one is considering spending $100,000-$1 million, one should do an actual cost-effectiveness analysis. So candidates here would be wild animal welfare, approval voting, improving institutional decision-making, climate change from an existential risk perspective, biodiversity from an existential risk perspective, governance of outer space etc. Though it is a significant amount of work to get a cost-effectiveness analysis up to peer review publishable quality (which we have found requires moving beyond Guesstimate, e.g. here and here), I still think that there is value in doing a rougher Guesstimate model and having a discussion about parameters. One could even add to one of our Guesstimate models, allowing a direct comparison with AGI safety and resilient foods or interventions for loss of electricity/industry from a long-term perspective.

Comment by Denkenberger on What are examples of technologies which would be a big deal if they scaled but never ended up scaling? · 2021-08-29T18:39:24.541Z · EA · GW

I think most technologies don't end up scaling. This says 2 to 10% of patents make enough money to maintain protection. A prototype is not required for a patent, but there would be lots of demonstrated ideas in the lab that are not patented. There is also the concept of the Valley of Death in commercialization where most technologies die. This is not necessarily the same as technologies that would be a "big deal" but I think it is a useful reference class.

Comment by Denkenberger on A Prototype Application for allocating people to Effective Projects · 2021-08-27T00:20:56.770Z · EA · GW

On Firefox and Chrome, the search on past jobs did not work correctly for me (e.g. "research" produced no results even though "Research and Development Managers" was a job in the list), and I couldn't see a way to select any jobs. But I was glad to see ALLFED mentioned in your nice video!

Comment by Denkenberger on Mission Hedgers Want to Hedge Quantity, Not Price · 2021-08-23T23:34:30.421Z · EA · GW

Interesting points.

We actually want to hedge global temperature, which isn't perfectly related to oil consumption. Is there a better hedge we could use?

Also, climate change would be more related to cumulative oil production, rather than annual. I think it would be better to find something that is more reactive to the warming. One candidate is food. One might think that if climate change negatively hurts food production, it would not be good to invest in. But because demand for food is inelastic, if one were invested in diversified food, total revenue is likely to increase because food price would increase more than quantity would decrease. Food price would also likely increase if there were more population and more animal product consumption, both of which would would be correlated with climate change. Investing in companies with large food storage would be a particularly good hedge against abrupt food catastrophes.

Comment by Denkenberger on Intervention report: Agricultural land redistribution · 2021-08-17T21:55:59.098Z · EA · GW

It does matter, because if it were log base 10, it would imply that the yield of the fields in 1982 varied approximately a factor of 30, which I would have trouble believing. But with the natural logarithm, it is only roughly a factor of four, which is much more reasonable.

Comment by Denkenberger on What EA projects could grow to become megaprojects, eventually spending $100m per year? · 2021-08-09T23:29:05.476Z · EA · GW

I have claimed that the first few hundred million dollars of preparation for agricultural and electricity disrupting GCRs is competitive with AGI safety for the longterm, and preparation for agricultural GCRs is more cost effective than GiveWell interventions. Since these catastrophes could happen right away, I think it does make sense to scale up quickly to $100 million per year to get the preparation fast. Beyond research, this money could be used for piloting new technologies and developing response plans and training. To maintain $100 million per year may then be lower cost effectiveness than AGI safety at the expected margin, but would still provide additional value and may be competitive with other priorities. Projects could include subsidizing resilient food sources such as seaweed, cellulosic sugar, methane single cell protein, etc. Or building factories flexibly such that they could switch quickly from producing animal feed or energy to human food. These could easily be many billions of dollars per year.

Comment by Denkenberger on Mushroom Thoughts on Existential Risk. No Magic. · 2021-08-08T04:21:45.528Z · EA · GW

Carla-nice piece! I direct the Alliance to Feed the Earth in Disasters (ALLFED). We are indeed concerned about tail risks from climate change. We have also considered two different resilient foods for global agricultural shocks related to fungi: mushrooms and fungus grown in bioreactors. Mushrooms have the advantage of the potential to scale extremely rapidly and grow on fiber (e.g. agricultural residues or wood), but they are expensive. Quorn is a fungus that is currently grown on grain, so in a catastrophe, eating the grain would generally make more sense (though Quorn would be better than feeding animals). However, it would be possible to have fungus in a bioreactor grow on fiber, which would be resilient. But unfortunately, neither of these bioreactor options is very economical at this point.

Comment by Denkenberger on What is the role of public discussion for hits-based Open Philanthropy causes? · 2021-08-07T06:30:14.469Z · EA · GW

I do think there's hope for some quantitative estimates even in the speculative cases; for example Open Phil has mentioned that they are investigating the "value of the last dollar" to serve as a benchmark against which to compare current spending (though to my knowledge they haven't said how they're investigating it).

Ajeya explains it in her 80k interview and the result is:

"this estimate is roughly $200 trillion per world saved, in expectation. So, it’s actually like billions of dollars for some small fraction of the world saved, and dividing that out gets you to $200 trillion per world saved. This is quite good in the scheme of things, because it’s like less than two years’ worth of gross world product. It’s like everyone in the world working together on this one problem for like 18 months, to save the world."

Comment by Denkenberger on Intervention report: Agricultural land redistribution · 2021-07-23T06:00:56.489Z · EA · GW

Very interesting! You may want to note that in Figure 9, log refers to log base e (ln), not log base 10.

Comment by Denkenberger on Shallow evaluations of longtermist organizations · 2021-06-27T02:34:39.781Z · EA · GW

This is most likely my fault; I think I got confused between and

We tried to buy the .org domain, but unfortunately it was not for sale.

Essentially I'd expect any preparation to at least fail partially, fail to get implemented, be ignored, not survive in institutional memory, etc.

There are definitely a lot of failure modes, though part of the money should go to updating institutions as staff turn over.

Thanks for updating the Guesstimate.

Separately, your numbers still seem fairly high. Suppose that in 1980 you had $100M and knew that there was going to be a pandemic (or another global financial crisis) in the next 100 years, but didn't knew the details; it seems unlikely that you could have made the covid pandemic or the 2008 financial crisis more than 10% better.

Good question. I think these are quite different because billions of dollars had been put into preparedness, at least for a pandemic. Though billions of dollars have been put into preventing a nuclear war (and reducing weapon stockpiles), we could not find anything preparing for feeding populations for a multiyear catastrophe. I think generally there are logarithmic returns, which means the first amount of money spent on a problem has much greater marginal cost effectiveness.

Comment by Denkenberger on Shallow evaluations of longtermist organizations · 2021-06-26T02:56:38.388Z · EA · GW

Thanks for considering ALLFED. We try to respond to inquiries quickly. We have looked back, and have not be able to locate any such inquiries. We will be finalizing our 2020 report with financial details soon.

Thanks a lot for the engagement in the cost-effectiveness model. To clarify, the cost of preparation does not include the scale up in a catastrophe. The idea is that the resilient foods (we are rebranding away from “alternative foods”) could be scaled up without large-scale preparation (e.g. countries would repurpose the paper factories to produce food after the catastrophe, rather than spending billions of dollars ahead of time). Most of the promising resilient foods have already been commercialized. In this paper, we found that if there were no resilient foods, expenditure on stored foods in a catastrophe would be approximately $90 trillion and about 10% of people would survive. However, if resilient foods could be produced at $2.5 per dry kilogram retail, 97% of people would survive but the total expenditure would only be ~$20 trillion. So one could argue that resilient foods would actually save money in a catastrophe. But we did not include that effect in the cost-effectiveness model.

I expect that affecting a large amount of the Earth's future impact (i.e., 3 to 50% of the future impact of humanity) would be very hard even in extreme circumstances.

Just to make sure we are on the same page, if there were a 10% probability of full-scale nuclear war in the next 30 years and there were a 10% reduction in the long-term future potential of humanity given nuclear war, and if planning and R&D for resilient foods mitigated the far future impact of nuclear war by 50%, then that would improve the long-term potential of humanity by 0.5 percentage points (the product of the three percentages).

Comment by Denkenberger on What are the 'PlayPumps' of cause prioritisation? · 2021-06-25T07:03:38.411Z · EA · GW

Opposing the Green Revolution in Africa here:

"Borlaug's initial efforts in a few African nations have yielded the same
rapid increases in food production as did his initial efforts on the 
Indian subcontinent in the 1960s. Nevertheless, Western environmental 
groups have campaigned against introducing high-yield farming techniques to Africa, and have persuaded image-sensitive organizations such as the Ford Foundation and the World Bank to steer clear of Borlaug."

The Green Revolution wasn't even GMOs - just dwarf crop varieties, fertilizers, and pesticides. Not only did opposition to this mean many more people dying of malnutrition, but also more rainforest cut down, so more loss of biodiversity and climate change. 

Comment by Denkenberger on Do we need to keep increasing energy consumption? · 2021-06-19T00:01:22.445Z · EA · GW

I've worked in energy efficiency, so I've thought about this a lot. Pure energy efficiency is getting the same utility with less energy. However, energy conservation is generally regarded as situations where you have to give something up, such as thermal comfort, convenience, travel, second homes etc. One successful example of energy efficiency is appliances in the United States such as clothes washers, refrigerators, and dishwashers now use about 1/4 as much energy as they did a few decades ago at negative costs for CO2 saved. I think there are still many opportunities to reduce energy use cost effectively and get the same utility. But once you go to non-cost-effective energy efficiency or directly limiting activities, the economic costs (taking into account non-monetary factors) get extremely high. I've run a few numbers and have gotten around $1,000 to $10,000 per ton CO2, versus ~$100 per ton CO2 for things including renewable energy and air capture. So I don't think we should be directly limiting activities.

Comment by Denkenberger on A bunch of reasons why you might have low energy (or other vague health problems) and what to do about it · 2021-06-14T04:02:08.120Z · EA · GW

I would add sleep apnea as a possible cause of fatigue. The test is relatively inexpensive, and the CPAP machine can be a game changer.

Comment by Denkenberger on Should aid organizations accept ETH donations? · 2021-05-20T01:03:06.752Z · EA · GW

Yes, these are extremely energy efficient ways of saving lives. I think most people would think it is ethical to save lives from radon gas causing cancer, despite the solution being more ventilation. If it costs $5 million to save a life (typical value in the US), since electricity costs about $0.10 a kilowatt hour, then we would be willing to spend 50 million kWh to save a life! In reality, not all of the cost goes to energy, but a lot of the cost would be saved in the form of heating fuel, which is much less than $0.10 a kilowatt hour. This can be used to show that the energy used to fly flowers grown in Africa to Europe is also a relatively energy efficient way of saving lives.

Comment by Denkenberger on Some quick notes on "effective altruism" · 2021-03-28T07:27:11.968Z · EA · GW

Though I was surprised when I read the results of the first EA survey because I was expecting the majority of non-student EAs would donate 10% of their pretax income, I don't think that saying that EA donations are extremely low is quite fair. The mean donation of EAs in the 2019 survey was 7.5%. The mean donation of Americans of pretax income is about 3.6%. However, with a significant number of EAs outside of the US giving less, the fact that many EAs are students, and the since I think that the EA mean is by person rather than weighted by donation (as the US average number is), I would guess EAs donate about 3-5 times as much as the same demographic that is not an EA. I do think that we could do better, and a lot of good could come from more donations.

Comment by Denkenberger on Why I find longtermism hard, and what keeps me motivated · 2021-02-25T05:15:20.253Z · EA · GW

Nice piece! Though this does not work for all longtermist interventions, some find it motivating that AGI safety, alternative foods, and interventions for losing electricity/industry (and probably other interventions) likely save lives in the present generation more cost-effectively than GiveWell top charities. This book argues that doing more to mitigate catastrophes can be justified by concerns of the present generation.

Comment by Denkenberger on Big List of Cause Candidates · 2021-02-18T23:47:05.974Z · EA · GW

Congratulations on winning the comment award! I definitely agree we should broaden the scenarios at which we look. You can see some work on the long term future impact of lesser catastrophes here and here.

  • Solar storm disruption

Yes, and other catastrophes that could disrupt electricity/industry, such as high-altitude detonation of a nuclear weapon causing an electromagnetic pulse, coordinated cyber attack on electricity (perhaps narrow AI enabled), or an extreme pandemic causing the desertion of critical jobs may be important to work on.

  • CO2 emissions from fossil fuels and other climate change rendering the atmosphere unbreathable (this would be a good old fashioned X-risk, but seems like one that no-one has discussed - in Toby's book he details some extreme scenarios where a lot of CO2 could be released that wouldn't necessarily cause human extinction by global warming, but that some of my back-of-the-envelope maths based on his figures seemed consistent with this scenario)
  • CO2 emissions from fossil fuels and other climate change substantially reducing IQs

Even 7000 ppm (0.7%) CO2 only has mild effects, and this is much higher than is plausible for Earth's atmosphere in the next few centuries.

  • Various 'normal' concerns: antibiotic resistant bacteria; peak oil; peak phosphorus;

It is possible that overreaction to these could cause large enough increases in prices to make poor of the world significantly worse off, which could cause political instability and eventually lead to something like nuclear war. But I think it is much lower probability than those that could directly reduce food supply abruptly by order of magnitude 10%.

  • substantial agricultural collapse; moderate climate change;

I think the moderate climate change, perhaps 2°C over a century, is difficult to find a direct route to a collapse. However, it would make a 10% food production shortfall from extreme weather more likely. And there are many other catastrophes that could plausibly produce a 10% food production shortfall, such as:

1 Abrupt climate change (10 C loss over a continent in a decade, which has happened before)

2 Extreme climate change that is slow (~10 C over a century)

3 Volcanic eruption like Tambora (which caused the year without a summer in 1816: famine in Europe)

4 Super weed that out-competes crops, if a coordinated attack

5 Super crop disease, if a coordinated attack

6 Super crop pest (animal), if a coordinated attack

7 Losing beneficial bacteria abruptly

8 Abrupt loss of bees

9 gamma ray burst, which could disrupt the ozone layer

  • major wars;

This could be a 10% infrastructure destruction, so I think it could destabilize. Disruption of the Internet for an extended period globally could also cut off a lot of essential services.

  • reverse Flynn effect;

Even if the Flynn effect has stalled in developed countries (has it?), I still think globally over this century we are going to have a massive positive Flynn effect as education levels rise.

Other concerns that I don't know of, or that no-one has yet thought of

Agreed, which is a reason that resilience and response are also important.

Comment by Denkenberger on Religious Texts and EA: What Can We Learn and What Can We Inform? · 2021-02-04T07:09:08.686Z · EA · GW

It sounds similar to this project from 5 years ago.

Comment by Denkenberger on How does Amazon deforestation actually work? It's not about soy. · 2021-01-29T19:50:48.638Z · EA · GW

succeeded by land speculators and poor ranchers from other regions, attracted by low-price lands; they’ll put down the remaining forest to raise cattle and subsistence agriculture – with productivity decreasing each year, until they exhaust soil nutrients. 

Indeed, swidden (slash and burn) agriculture was common historically (including in Europe and the southern United States). However, now that we can replace nutrients with artificial fertilizers, it seems like that would be more profitable. Do you have data on what fraction of the land is just abandoned?

Comment by Denkenberger on Things I recommend you buy and use. · 2021-01-29T04:58:37.429Z · EA · GW

Nice list! How many times can you wear a pair of the silicone earplugs?

Comment by Denkenberger on Money Can't (Easily) Buy Talent · 2021-01-27T03:55:55.939Z · EA · GW

I agree with Peter - ALLFED has been training up volunteers and we could bring on a lot more talent full-time (both our volunteers and from the general EA pool) if we had more money.

Comment by Denkenberger on Actually possible: thoughts on Utopia · 2021-01-25T03:59:17.442Z · EA · GW

Nice post - I think it is good to reflect on what we might achieve, rather than only focusing on reducing X risk.

But unlike Heaven, Utopia, if something like it ends up getting built, will be a specific, concrete, physical world, with attendant frictions and problems, idiosyncrasies and contingencies; its own ways of distributing resources, resolving/preventing conflicts, and so on; and ultimately, with fundamental limitations on what can be done.

I’m not sure how feasible these are, but would personal universes address some of these issues?

Comment by Denkenberger on Notes: Stubble Burning in India · 2021-01-16T22:23:25.500Z · EA · GW

Although stubble burning is an effective way to deal with crop residue in the short term, the practice is pretty bad for the soil.

For one, you lose the nitrogen in the residue to the air through burning. With all the cattle in India, I would think you could just feed the residue to them, and this says it could make up about 50% of their diet. And you might be able to grab some human edible calories first through the leaf protein concentrate process. There is also cellulosic ethanol or cellulosic sugar, though those are likely not economical now.

Comment by Denkenberger on International Cooperation Against Existential Risks: Insights from International Relations Theory · 2021-01-15T04:21:59.843Z · EA · GW

I agree that IR is important for EA. I would be particularly interested to hear your opinion on collapse of civilization scenarios here.

Comment by Denkenberger on EA and the Possible Decline of the US: Very Rough Thoughts · 2021-01-12T04:44:07.503Z · EA · GW

I was surprised you did not mention nuclear war as a cause of the decline of the US. If you take Luisa Rodriguez's average estimate of US-Russia nuclear war, 0.38% per year, that's about 20% chance in 50 years. And that does not take into account possible US-China nuclear war. I think even if nuclear winter did not happen, just the war would cause a significant decline in the US. So would that meet your definition?

Comment by Denkenberger on Is Earth Running Out of Resources? · 2021-01-10T02:18:17.965Z · EA · GW

More concerning than jet engines might be the high efficiency natural gas turbines for generating electricity. However, it looks like Ruthenium is even better than Rhenium for these applications. And in general, you can avoid rare earth metals and just accept slightly lower performance for combustion turbines, wind turbines, electric car motors, LED lights, solar cells, etc.

Comment by Denkenberger on Everyday Longtermism · 2021-01-06T05:55:48.200Z · EA · GW

I believe the framing in the 80,000 Hours podcast was something like when we run out of targeted things to do. But if we include global warming, depending on your temperature increase limit, we could easily spend $1 trillion per year. If people in developed countries make around $30,000 a year and they donate 10% of that, that would require about 300 million people. And of course there are many other global catastrophic risks. So I think it's going to be a long time before we run out of targeted things to do. But it could be good to do some combination of everyday longtermism and targeted interventions.

Comment by Denkenberger on What is the likelihood that civilizational collapse would directly lead to human extinction (within decades)? · 2021-01-02T00:43:55.759Z · EA · GW

I was glad to see some discussion of potential irrational behavior. As was mentioned recently on the EA forum, I think there is a tendency for rational people to assume that other people will behave more rationally than they actually will. I think we have seen a lot of irrationality in the handling of COVID. And I think it would be far worse in the case of larger catastrophes. I think I remember reading that if something like half or three quarters of one's close family and friends died, there was a high chance of one becoming schizophrenic.

I think the fact that so many thoughtful people think collapse of civilization is likely from slow climate change (e.g. 50/50 chance for 4°C temperature rise according to Mark Lynas in his 80,000 Hours podcast), which is far less extreme than 50% of people dying, should give us pause. I tend to be more optimistic, but I do recognize the possibility that stressors could be handled poorly.

Comment by Denkenberger on Big List of Cause Candidates · 2020-12-28T23:13:44.240Z · EA · GW

Great list! It reminds me of Peter McClusky's "Future of Earning to Give" post showing that there is plenty of room for more funding of high impact projects.

Comment by Denkenberger on What is the likelihood that civilizational collapse would directly lead to human extinction (within decades)? · 2020-12-28T04:45:20.250Z · EA · GW

Here, food stocks is defined in the source paper as a group of “92 products” used “to reconstruct 50 years of aggregated food reserves, expressed in caloric equivalent (kcal), at the regional and global scales.” (Laio et al. 2016)

This is a great reference in that it does more than just look at stocks of grain. It does it for the end of each year, which is a pretty favorable case. The stocks of food would be considerably less right before harvest in the northern hemisphere, I would estimate ~3 months of food instead of 6. Also, their number is assuming 2880 kcal per day per person, which is appropriate to account for waste, but would not account for edible food fed to animals. But I agree with your rationing vegan number of approximately seven months if the catastrophe happened at the end of the year (but about half that for the worst timing scenario).

Comment by Denkenberger on What is the likelihood that civilizational collapse would directly lead to human extinction (within decades)? · 2020-12-27T22:44:37.940Z · EA · GW

I am also excited to see work on such an important, neglected topic.

While I haven’t looked into this much, I feel fairly convinced that hundreds of thousands or millions of people could survive using traditional approaches to agriculture in parts of the world with more moderate climate effects (and basic mitigation strategies, like switching to crop types that are more resilient to temperature and precipitation fluctuations).

ALLFED has indeed found a number of cool tolerant crops that could likely grow in nuclear winter conditions in the tropics. However, they are generally planted far away from the tropics, so if there were not long distance cooperation, the situation would be bad. Even without long distance cooperation, artifacts have moved thousands of kilometers, but I think it takes thousands of years. One possibility would be relocating crops from nearby mountains, but that would only work in specific circumstances.

On the other hand, there could be long distance movement of people, perhaps with remaining above ground fossil fuel and current ships. But then places where agriculture is easier in nuclear winter such as Oceania could be overwhelmed with migrants.

The carrying capacity of the Earth for hunter-gatherers is thought to be around 10 million if the survivors regress to pre-paleolithic levels of technology (if they lose, for example, flakes, handaxes, controlled use of fire, and wooden spears) (Taiz, 2013). 

It appears that this is not the correct reference for that quote. Taiz says that the global population was 10 million in 8,000 BC and another one of your references said that by then the hunter gatherers had covered the globe and had 10 million population (some say only 1 million) and they would generally have had those pre-paleolithic technologies. Ellis says 100 million hunter gatherers would be possible with prehistoric technology, which is much higher than the actual population in 8,000 BC (though it would be consistent with your statement).

Several experts, including ALLFED director David Denkenberger, have affirmed this conclusion — they do not expect humanity to dip below the minimum viable population even in relatively extreme sun-blocking scenarios.

To be clear, I don’t expect it, but I think extinction is a non-negligible probability.

Before getting into the likelihood that society would recover from civilizational collapse under these starting conditions, I’ll briefly discuss whether we should expect human civilization to actually collapse in my sense in this scenario.

Doesn’t appear to be public?

Comment by Denkenberger on What is the likelihood that civilizational collapse would directly lead to human extinction (within decades)? · 2020-12-27T19:35:21.600Z · EA · GW

Regarding case 1, with a pandemic leaving 50% of the population dead but no major infrastructure damage, I think you can make much stronger claims about there not being 'civilization collapse' meaning near-total failure of industrial food, water, and power systems. Indeed, collapse so defined from that stimulus seems nonsensical to me for rich quantitative reasons.


If there were a pandemic heading toward 50% population fatality, I think that it is likely that workers would not show up to critical industries and there would be a collapse of industrial civilization. I looked into whether the military could replace those workers, and it did not look feasible. Whether there would be further collapse of large-scale cooperation is less certain. If that cooperation is maintained, I agree it would be possible to have agricultural productivity similar to preindustrial Europe. However, it would mean a very rapid scale up of hand/animal farming equipment, and hand powered wells, carts that could be drawn by animals, etc (which ALLFED is planning on investigating). Some people say that modern crop varieties would actually do worse than traditional crop varieties if there were no artificial fertilizers and pesticides. If that were true or if scaling of tools were difficult, then we could have much worse agricultural productivity than preindustrial Europe.

Loss of rapid communication would likely imply fragmentation of large countries, if it is true that empires can only be maintained with I think a ~14 day communication radius. Furthermore, it is possible that cooperation outside of 100 person groups is lost, particularly because of fear of the disease. In this case, I think it is likely with current preparation to only be able to do hunting and gathering. In addition, the hunting and gathering population density could be much less than historic, because the overshoot in population density could mean that plants and animals that are good to eat could be driven to extinction by desperate humans. 

Though it is possible that current food storage could be protected well, it is not clear to me that there would be a strong defense advantage. The desperate attackers would have weapons as well. If we go significantly above the carrying capacity and food is distributed fairly equally, then everyone would starve.

Comment by Denkenberger on Books / book reviews on nuclear risk, WMDs, great power war? · 2020-12-26T08:10:11.491Z · EA · GW
  • Feeding Everyone No Matter What
    • I believe this is mostly focused on interventions to mitigate how bad nuclear winter would be, if it happened.

Yes, there is more detail on the nuclear risk in this paper. And this paper on a fault tree model of the chance of nuclear war.

Comment by Denkenberger on Careers Questions Open Thread · 2020-12-15T07:56:02.262Z · EA · GW

Another option for engineering is work on alternative foods for catastrophes - there are many engineering projects listed here.  You could volunteer/intern at ALLFED even as an undergrad.

Comment by Denkenberger on "Patient vs urgent longtermism" has little direct bearing on giving now vs later · 2020-12-13T19:11:09.950Z · EA · GW

Yes, with how under invested in GCR mitigation is now, I think it is better to have many resources for longtermism sooner.

Comment by Denkenberger on Uncorrelated Investments for Altruists · 2020-12-07T23:24:57.342Z · EA · GW

That is true if you sell more when the market is down, you will have less to donate later. But I would think that the higher expected return would overwhelm this. This is what the Princeton endowment argued-I think their portfolio got cut in half around 2008, and then they did a bigger payout as a percentage. But they said that because they had invested with high expected return, they were still in much better situation than investing cautiously. It would be great in your next project to have some visualizations of how the investments perform over time and what the payouts are. Then we could see how much charity smoothing there would be for the primary donor (given some value function, which I would argue should have a larger downside than logarithmic because of inefficient cutting), and consequently how much more valuable it is for small donors to be uncorrelated. I'm looking forward to reading about your new model.

Comment by Denkenberger on Uncorrelated Investments for Altruists · 2020-12-04T05:10:54.666Z · EA · GW

I loved the article on  investing like an alien. I'm very glad to see your recognition that one can indeed beat the market long term with value and momentum, because most EAs have been skeptical of this. Though I agree with the general principle of the advantage of uncorrelated assets, I am skeptical that shorting the market cutting your expected return in ~half is optimal. You may be modeling payouts to charity proportional to asset value, like a foundation is roughly managed. In my experience, when the market is down a lot, the payouts would increase as a percentage, because donors would not want to have inefficient cuts in charities. So this would reduce the value of an individual's holdings increasing during those times. But even if we assume the payout is proportional to the portfolio value, sometimes that might mean half as much payout, which would make the marginal value double. However, this will be a very small percent of the years over the long term. And if you go from 20% return to 10% return, that is a factor of roughly 17 lower appreciation over 30 years. So I would think it would be more valuable to have that higher return than less correlation.

Comment by Denkenberger on Introducing High Impact Athletes · 2020-12-03T07:19:11.716Z · EA · GW

Agreed, and actually Americans donate closer to 4% of pretax income.

Comment by Denkenberger on ALLFED 2020 Highlights · 2020-11-28T04:48:23.139Z · EA · GW

Thanks for the feedback. We do think there is a compelling case for saving expected lives in the present generation cost effectively. On the long-term future, we do not have a quantitative model for how important extinction versus unrecoverable collapse versus negative trajectory changes are in these scenarios (and in terms of mitigation from interventions). So I would say it is closest to:

reducing numbers of deaths and global instability is just a good proxy for reducing existential risk


As Nick Beckstead said:

In this way, our situation seems analogous to the situation of someone who is caring for a sapling, has very limited experience with saplings, has no mechanistic understanding of how saplings work, and wants to ensure that nothing stops the sapling from becoming a great redwood. It would be hard for them to be confident that the sapling’s eventual long-term growth would be unaffected by unprecedented shocks—such as cutting off 40% of its branches or letting it go without water for 20% longer than it ever had before—even taken as given that such shocks wouldn’t directly/immediately result in its death. For similar reasons, it seems hard to be confident that humanity’s eventual long-term progress would be unaffected by a catastrophe that resulted in hundreds of millions of deaths.

Comment by Denkenberger on Where are you donating in 2020 and why? · 2020-11-28T00:05:25.236Z · EA · GW

Thanks, MichaelA! On neglectedness, it is true that $3 million is very large in this space. However, the Open Phil funded group decided to propose to work on alternative foods that they already had expertise in. This includes cellulosic sugar, duckweed, forest products including inner bark, mushrooms, and sprouts. With the exception of cellulosic sugar, these alternative foods are higher cost than the ones that ALLFED is prioritizing. Low cost is important for feeding nearly everyone and maintaining stability of civilization. Therefore, we don't believe that the highest priority sun-blocking solutions (cellulosic sugar, methane single cell protein, hydrogen single cell protein, cold tolerant crops, greenhouses, seaweed, and leaf protein concentrate) are significantly less neglected now. Furthermore, the Open Phil funded project is generally not working on interventions for losing electricity/industry, so that remains highly neglected.

Comment by Denkenberger on [Question] Pros/Cons of Donor-Advised Fund · 2020-11-23T05:36:46.812Z · EA · GW

I confirmed with them that the donor has the control of where the money goes, unless they deem it a hate group. And they are also okay with transferring to another DAF.

Comment by Denkenberger on Why those who care about catastrophic and existential risk should care about autonomous weapons · 2020-11-16T02:42:05.057Z · EA · GW

Thanks - I think there are scenarios where AWSs could pose a GCR.

A large-scale nuclear war is unbelievably costly: it would most likely kill 1-7Bn in the first year and wipe out a large fraction of Earth’s economic activity (i.e. of order one quadrillion USD or more, a decade worth of world GDP.)

I've seen mortality estimates and produced one of my own, but I haven't seen economic damage estimates. Do you have a reference for this?

Comment by Denkenberger on Nuclear war is unlikely to cause human extinction · 2020-11-10T04:34:57.405Z · EA · GW

Thanks for the post. The updated nuclear winter modeling is Coupe 2019 - it has similar results to the 2007 work. The new work was funded by Open Phil. I agree that extinction is quite unlikely, but I think there are a few routes to get there. Many people mention the lower climate impacts in places like New Zealand, but they do not consider the possibility of refugees overwhelming New Zealand. You may very well be right that some food storage will be protected, but I don't think it's guaranteed that people could or would forcibly repel the desperate people trying to get food. Furthermore, if there is an eventual collapse of anthropological civilization (cooperation outside tribes), we may have to go back to hunting and gathering, and there is evidence that that transition may not go well (The Secret of Our Success book). And the current hunter gatherers generally don't have much food storage, so they would likely die out.

But then I agree with Max Daniel that even if extinction is unlikely, I think worse trajectory changes have significant probability, which is supported by the poll of GCR researchers here.

As Robock points out, even without firestorms (simultaneous burning of a large area), some smoke can go into the upper troposphere and be lofted into the stratosphere. Indeed, this has been demonstrated for wildfires (which are not firestorms).

Comment by Denkenberger on N-95 For All: A Covid-19 Policy Proposal · 2020-11-01T18:50:13.808Z · EA · GW

Note that the shield claims to block droplets, but not aerosols. Aerosols will go around any shield. Even this shield with some loosefitting fabric only blocked ~10% of aerosols. Making it tight fitting with an elastic band improves it. But really what would be much safer is surgical mask material or N-95 material that is tightfitting.

I do think that appearance is critical, at least in developed countries. In my experience, most people use only cloth masks, which block about 1/4 of aerosols. Moving to a surgical mask blocks about three quarters, which is an enormous improvement. There are concerns about long reuse of mass that are designed to be disposable, but they are doing UV treatment, and an easy thing is just putting it in an oven at about 80C for 45 minutes. A compromise could be a surgical mask underneath an attractive cloth mask, which is still easier to breath than N-95. Surgical masks seem to be easily available, and some are even attractive.