Dr. David Denkenberger co-founded and directs the Alliance to Feed the Earth in Disasters ( and donates half his income to it. He received his B.S. from Penn State in Engineering Science, his masters from Princeton in Mechanical and Aerospace Engineering, and his Ph.D. from the University of Colorado at Boulder in the Building Systems Program. His dissertation was on his patented expanded microchannel heat exchanger. He is an assistant professor at University of Alaska Fairbanks in joint in mechanical engineering and Alaska Center for Energy and Power. He received the National Merit Scholarship, the Barry Goldwater Scholarship, the National Science Foundation Graduate Research Fellowship, is a Penn State distinguished alumnus, and is a registered professional engineer. He has authored or co-authored 104 publications (>2700 citations, >50,000 downloads, h-index = 27, third most prolific author in the existential/global catastrophic risk field (, including the book Feeding Everyone no Matter What: Managing Food Security after Global Catastrophe. His food work has been featured in over 25 countries, over 200 articles, including Science, Vox, Business Insider, Wikipedia, Deutchlandfunk (German Public Radio online), Discovery Channel Online News, Gizmodo,, and Science Daily. He has given interviews on 80,000 Hours podcast and Estonian Public Radio, WGBH Radio, Boston, and WCAI Radio on Cape Cod, USA. He has given over 80 external presentations, including ones on food at Harvard University, MIT, Princeton University, University of Cambridge, University of Oxford, Cornell University, University of California Los Angeles, Lawrence Berkeley National Lab, Sandia National Labs, Los Alamos National Lab, Imperial College, and University College London.

Wiki Contributions


Is there a market for products mixing plant-based and animal protein? Is advocating for "selective omnivores" / reducitarianism / mixed diets neglected - with regards to animal welfare?

And the good old (not very tasty, I admit) cheap plant-burgers are being totally replaced by the delicious & expensive & very well-marketed "fake meat burgers" everywhere.


The last calculation I did indicated that the old plant-based burgers were lower price per mass, but actually higher price per calorie than the new ones. And the price for the new ones is falling rapidly.

A huge opportunity for impact: movement building at top universities

I agree that filtering is important - the easy thing to do is target the honors colleges (or whatever they call them) within the universities.

A huge opportunity for impact: movement building at top universities

Please see my reply to devanshpandey. Also, I edited that I was interested in seeing the math on standard deviations between universities.

A huge opportunity for impact: movement building at top universities

Of course we need to prioritize. The Nobel example we have data for, but I think that is too high a bar. My point is that there are probably a similar number of potential EAs at the big relatively high ranking state schools like University of Illinois at Urbana Champaign or University of Texas at Austin as there are at Princeton. The state school students may have lower wealth and political connections, but I think the capability is there (and perhaps less entitlement). (Disclosure: I went to Penn State, Princeton, and University of Colorado at Boulder.)

Biosecurity needs engineers and materials scientists

There are also alternative proteins and resilient foods (ALLFED) for physical engineers.

A huge opportunity for impact: movement building at top universities

I am skeptical and would like to see the math on standard deviations. For the US, according to this, about one third of Nobel prizes were awarded to people who did their undergraduate at a non top 100 global university (and I'm pretty sure it would be the majority outside the global top 20 that are in the US). And you don't have to win a Nobel Prize in order to become an EA! So I think there is lots of potential talent for EA outside the global top 100, at least at the undergraduate level. A key factor here is size - many of the most elite schools are not very big. For instance, the honors college at Penn State has similar SAT scores to Princeton, and it has about half as many undergrads as Princeton. At the graduate level, I think the talent tends to concentrate more, but I still think there is significant talent outside the global top 100. 

(Edit: Penn State honors college is larger than Swarthmore.)

Zvi's Thoughts on the Survival and Flourishing Fund (SFF)

The substantive complaint was that they [ALLFED] did an invalid calculation when calculating the annual probability of nuclear war. They did a survey to establish a range of probabilities, then they averaged them. One could argue about what kinds of ‘average them’ moves work for the first year, but over time the lack of a nuclear war is Bayesian evidence in favor of lower probabilities and against higher probabilities. It’s incorrect to not adjust for this, and the complaint was not merely the error, but that the error was pointed out and not corrected.

Tl; dr: ALLFED appreciates the feedback. We disagree that it was a mistake - there were smart people on both sides of this issue. Good epistemics are very important to ALLFED.

Full version:

Zvi is investigating the issue. I won’t name names, but suffice it to say, there were smart people disagreeing on this issue. We have been citing the fault tree analysis of the probability of nuclear war, which we think is the most rigorous study because it uses actual data. Someone did suggest that we should update the probability estimate based on the fact that nuclear war has not yet occurred (excluding World War II). Taking a look at the paper itself (see the top of page 9 and equation (5) on that page), for conditional probabilities of occurrence for which effectively zero historical occurrences have been observed out of n total cases when it could have occurred, the probability in the model was updated according to a Bayesian posterior distribution with a uniform prior and binomial likelihood function. Historical occurrences updated in this way were A) the conditional probability that Threat Assessment Conference (TAC)-level attack indicators will be promoted to a Missile Attack Conference (MAC), and (B) the conditional probability of leaders’ decision to launch in response to mistaken MAC-level indicators of being under attack. Based on this methodology, it would be double-counting to update their final distribution further based on the historical absence of accidental nuclear launches over the last 76 years.

But what we do agree on is that if one starts with a high prior, one should update. And that's what was done by one of our coauthors for his model of the probability of nuclear war, and he got similar results to the fault tree analysis. Furthermore, the fault tree analysis was only for inadvertent nuclear war (one side thinking they are being attacked, and then "retaliating"). However, there are other mechanisms for nuclear war, including intentional attack, and accidental detonation of a nuclear weapon and escalation from there. Furthermore, though many people consider nuclear winter only possible for a US-Russia nuclear war, now that China has a greater purchasing power parity than the US, we think there is comparable combustible material there. So the possibility of US-China nuclear war or Russia-China nuclear war further increases probabilities. So even if there should be some updating downward on the inadvertent US-Russia nuclear war, I think the fault tree analysis still provides a reasonable estimate. I also explained this on my first 80k podcast.

Also, we say in the paper, "Considering uncertainty represented within our models, our result is robust: reverting the conclusion required simultaneously changing the 3-5 most important parameters to the pessimistic ends." So as Zvi has recognized, even if one thinks the probability of nuclear war should be significantly lower, the overall conclusion doesn't change. We have encouraged people to put their own estimates in.

Again, we really appreciate the feedback. Good epistemics are very important to us. We are trying to reach the truth. We want to have maximum positive impact on the world, so that's why we spend a significant amount of time on prioritization.

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