Director, Associate Professor @ Alliance to Feed the Earth in Disasters (ALLFED), University of Canterbury
2387 karmaJoined Apr 2015Working (6-15 years)Christchurch, New Zealand



Dr. David Denkenberger co-founded and directs the Alliance to Feed the Earth in Disasters (ALLFED.info) 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 an expanded microchannel heat exchanger, which he patented. He is an associate professor at the University of Canterbury in mechanical engineering. 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 134 publications (>4000 citations, >50,000 downloads, h-index = 32, second 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, Phys.org, and Science Daily. He has given interviews on 80,000 Hours podcast (here and here) 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.

How others can help me

Referring potential volunteers, workers, board members and donors to ALLFED.

How I can help others

Being effective in academia, balancing direct work and earning to give, time management.


This is a decent summary, but there are a couple corrections:

ALLFED increased paid team members, but much less than doubled (we have capacity to expand more quickly with additional funding).

We do have 17 advisory board members, but they represent 4 countries, not 9 (the 9 countries were represented by the 17 team members at the retreat).


Nice post!

The model does not predict much differences between the different scenarios until 2020-2030. Therefore, we only know that the model has not been falsified so far, but it is still unclear what the path is we are currently on.

I think it would be helpful to see an overlay of our actual trajectory. Though the absolute values of the models are not that different for the period 2000 to 2020, the slopes are quite different. I think there was a paper analyzing the fits including the slopes. The increase of production of food since the year 2000 has been much larger than any of the models predicted. Also, I think the increase in industrial capacity is higher than any of these models. Interestingly, some people interpret this as us overshooting farther, so then we will fall more dramatically. But because we generally have not seen reduction in slopes, I don't really see evidence for this, so I think that the optimistic interpretation is more likely to be right, basically that we have innovated around limits to growth so far.

Thanks for all you have done!

Finally, EAs have treated EtG as increasingly more weird, especially offline, defeating the original argument for engaging.

This is very disappointing, especially because, if you disregard "still deciding", EtG was the second most popular route to impact among EAs in the 2022 survey.

(leading a - dare I say - successful effective nonprofit)

Sure - go ahead and dare. :)

My day job is associate professor of mechanical engineering at University of Canterbury in New Zealand, and I volunteer for ALLFED. Nearly 100% of my donations are to ALLFED. I think that ALLFED is the most cost-effective way of improving the long run future at the margin (see here and here, though I'm not quite as bullish as the mean survey/poll results in those papers), but there are orders of magnitude of uncertainty, and I think more total money should be put into AGI safety.

As one who donates 50%, it doesn't seem like it should be that uncommon. One way I think about it is earning like upper-middle-class, living like middle-class, and donating like upper-class. Tens of percent of people work for tens of percent less money in sectors like nonprofits and governments. And I've heard of quite a few non-EAs who have taken jobs for half the money. And yet most people think about donating that large of a percent very differently than taking a job that pays less. I'm still not sure why - other than that it is uncommon or "weird." 

I agree that most academic research is a bad ROI but I find that a lot of this sort of 'nobody reads research' commentary is equating reads with citations which seems completely wrong. By that metric most forum posts would also not be read by anyone.

I agree-for one, the studies I've seen saying that the median publication is not cited are including conference papers, so if one is talking about the peer-reviewed literature, citations are significantly greater. I've estimated the average number of citations per paper is around 30 for the peer-reviewed literature. Furthermore, from what I've seen, the number of reads on places like ResearchGate and Academia.edu tend to be one to two orders of magnitude greater than the number of citations. So I think a reasonable expectation for a peer-reviewed paper is hundreds or thousands of reads.

The government could internalize this positive externality by providing incentives, like this.

I was assuming 50 % reduction in international trade, and 50 % of that reduction being caused by climatic effects, so only 25 % (= 0.5^2) caused by climatic effects. I have changed "50 % of it" to "50 % of this loss" in my original reply to clarify.

That makes sense. Thanks for putting the figure in! 

I guess famine deaths due to the climatic effects are described by a logistic function, which is a strictly increasing function, so I agree with the above. However, I guess the increase will be pretty small for low levels of soot.

If it were linear starting at 10.5 Tg and going to 22.1 Tg, versus linear starting at 0 Tg and going to 22 Tg, then I think the integral (impact) would be about four times as much. But I agree if you are going linear from 10.4 Tg versus logistic from 0 Tg, the difference would not be as large. But it still could be a factor of two or three, so I think it's good to run a sensitivity case.

Very interesting!

  • Space colonies. Fertility is low in wealthy countries with large unsettled territories (Canada, Australia), even though they are far more hospitable than other planets. There is no reason to think that space colonies alone will reverse the fertility decline.

I think the incentive for fertility depends on the level of connection with the Earth. If it were fully independent from Earth, it would have a strong incentive to increase population because there are large economies of scale in terms of increasing the standard of living, including being able to create more living space per person, more advanced electronics, media, etc.

Both sides targeted civilians in WWII. Hopefully that is not the case now, but I'm not sure.

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