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 124 publications (>3000 citations, >50,000 downloads, h-index = 28, 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 twice ( and ) 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.

Topic Contributions


Is Mineral Resource Scarcity a Risk Anyone is Researching? Worth Researching?

I've done some work on this and I made some comments on this 80k podcast. I don't think running out of mineral resources is a significant threat.

Who's hiring? (May-September 2022)

The Alliance to Feed the Earth in Disasters (ALLFED) is hiring for multiple roles, including a 501(c)(3) Project Coordinator.

Focus on Civilizational Resilience over Cause Areas

I agree that resilience is overall relatively neglected in the GCR community. Another organization working on this is the Alliance to Feed the Earth in Disasters (ALLFED). Also, you would probably be interested in this paper: Defence in Depth Against Human Extinction: Prevention, Response, Resilience, and Why They All Matter.

Animal Welfare & Alternative Proteins in the United Arab Emirates

With all the natural gas (methane) flaring in the UAE, this could be a good opportunity to do methane single cell protein as a meat substitute. ALLFED may be interested in collaborating.

The future of nuclear war

This is interesting-and scary. One small point is to make sure to include units, e.g.:

Gsponer calls 4th generation nuclear such weapons that will be pure fusion weapons with yields between 1-100 TNT:

I think I got from context that you mean tons of TNT equivalent, but most of the time when talking nuclear weapons it would be kilotons.

My thoughts on nanotechnology strategy research as an EA cause area

Very helpful post!

Cheap energy. Cheap, powerful manufacturing might enable the fabrication of cheap solar cells and cheap batteries that help to overcome intermittency in solar power, leading to very cheap solar power (although, naively, I’m unsure how large an effect this would be given that advanced nanotechnology wouldn’t on the face of it reduce land and labour costs).

If the typical solar cell thickness is 400 µm and a density of 2.3 kg/L and efficiency of 20%, with 1000 W/m2 and $1000/kg, this would be ~$5/W, which is significantly more expensive than current solar cells. However, some solar cells have much thinner active layers, so it could be lower cost. The cost of land is much less than the cost of the solar cells. Labor still could be significant. Batteries are already less than $1000 per kilogram, so the main question is how much better performance they would have.

General wealth / economic growth. On the face of it, if we can make high-performance materials and devices very cheaply, people will on average be very wealthy compared to today (whether this is a deviation from trend GDP growth will, of course, depend on when and how the technology is developed).

Drexler claims that (something similar to) complex APM would be able to manufacture products for $1/kg or less and with a throughput of 1kg every 3 hours or less per kg of machinery (for “$1/kg or less”, see, for example, Radical Abundance, 2013, p. 172; for “a throughput of 1kg every 3 hours or less per kg of machinery”, see Nanosystems, 1992, p. 1, 3rd bullet). I set a lower bar for my definition of consequential APM here [$1000/kg] because I think this lower bar is more than sufficient to imply an extremely impactful technology, while perhaps capturing a larger fraction of potential scenarios over the next few decades.

Some have noted that even at the one dollar per kilogram cost, manufacturing is a relatively small fraction of the economy, so if this were to go much smaller, it would not help that much. However, if you could get truly self replicating equipment that could just draw minerals from the ground and get energy from the sun, an individual with a plot of land could produce a big house, lots of cars, lots of consumer goods, etc., so then they would be very wealthy. If we just get $1000 per kilogram, I don't think it would save very much of the economy, so the main question is how much higher the performance would be.

Has anyone actually talked to conservatives* about EA?

Strong upvote. I would guess that another commonality between EAs and conservatives is not tending to resent the rich and their philanthropy, as many on the left do.

Should longtermists focus more on climate resilience?

I agree that there should be more focus on resilience (thanks for mentioning ALLFED), and I also agree that we need to consider scenarios where leaders do not respond rationally. You may be aware of Toby Ord's discussion of existential risk factors in the Precipice, where he roughly estimates a great power war might increase the total existential risk by 10% (page 176). You say:

What is the multiplying impact factor of climate change on x-risks – compared to a world without climate change?

If forced to guess, considering the effects of climate change, I believe a multiplying factor of at least an order of magnitude is conservative. However, further calculations and estimates are absolutely required to verify this.

So you're saying the impact of climate change is ~90 times as much as his estimate of the impact of great power war (900% increase versus 10% increase in X risk). I think part of the issue is that you believe the world with climate change is significantly worse than the world is now.  We agree that the world with climate change is worse than the business as usual, but to claim it is worse than now means that climate change would overwhelm all the economic growth that would have occurred in the next century or so. I think this is hard to defend for expected climate change. But this could be the case for the versions of climate change that ALLFED focuses on, such as the abrupt regional climate change, extreme weather including floods and droughts on multiple continents at the same time causing around a 10% abrupt food production shortfall, or the extreme global climate change of around 6°C or more. Still, I don't think it is plausible to multiply existential risks such as unaligned AGI or engineered pandemic by 10 because of these climate catastrophes.

Is it still hard to get a job in EA? Insights from CEA’s recruitment data

This is helpful, but there is a key difference between the EA job market and the general one: there are a limited number of positions in EA. I think a valuable metric that perhaps could be explored on the next EA survey is the level of EA “unemployment.” This could mean the number of EAs who would prefer to have a job at an EA aligned organization, but have not gotten one. I suspect this will be far higher than the general level of unemployment. As an example, say there are 50 EAs with a particular skill, and five EA jobs requiring that skill. Then if they all apply to those five jobs, 2% of the applicants will get a job in each case, but that is only 10% of the EAs getting a job, so there would be 90% “unemployment.” Whereas outside of EA, they could all apply to 50 jobs and all get jobs. This could be analogous to underemployment, such as PhDs who want a job such as academia that requires a PhD, but have not gotten one.

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