D

Denkenberger

Director, Associate Professor @ Alliance to Feed the Earth in Disasters (ALLFED), University of Canterbury
2420 karmaJoined Apr 2015Working (6-15 years)Christchurch, New Zealand

Bio

Participation
2

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.

Comments
644

Thanks for mentioning resilient foods! It is true that more food storage would give more time to scale up resilient foods. Stored food could be particularly valuable for some countries in loss of trade scenarios. Some have suggested that getting the World Trade Organization to change its rules would result in more food storage automatically. Still, I think the priority now is spending a few hundred million dollars total on resilient foods to research, pilot, and plan for them. If we extend your proposal for 20 years and for the world, then you are up to ~$1 trillion. I think this is significantly less likely to happen and lower cost effectiveness than resilient foods.

I love the cumulative probability graph!

There is a little probability mass on things which are a reasonable fraction of the great or hellish futures — mostly corresponding to worlds in which the lightcone is divided in some way

  • Trade means that the probability of such outcomes isn’t so high, and I’ll set them aside for now; however, I think that this would be a natural place to extend this analysis

Let's say the positive side of your graph has a logarithmic horizontal axis. I think there would be some probability mass that we have technological stagnation and population reductions, though the cumulative number of lives would be much larger than alive today. Then there would be some mass on maintaining something like 10 billion people for a billion years (no AI, staying on earth either due to choice or technical reasons). Then there would be another high slope region of AI doing a Dyson swarm, but either because of technical reasons or high discount rate, not going to other stars. Then there would be another high slope region where AI settles the galaxy, but again either because of technical reasons or discount rate, not going to other galaxies. Then there would be settling many galaxies. Then 30 orders of magnitude to the right, there could be another high slope region corresponding to aestivation. And there could be more intermediate states corresponding to various scales of space settlement of biological humans (and as you point out, different behaviors in different fractions of the space that can be settled). Are you are saying that if we have good reflective governance, we will have zero discount rate, so we will just do aestivation if that is optimal? Still, I think there could be technical barriers at various stages. But then would you argue that with good reflective governance we should be able to reach a high percent of the technically achievable value?

I think the reviewer may be concluding from the above that, given no international food trade, calorie consumption would be much lower, and therefore increasing food production via new food sectors would become much more important relative to distribution. I agree with the former, but not the latter. Loss of international food trade is more of a problem of food distribution than production. If this increased thanks to new food sectors, but could not be distributed to low-income food-deficit countries (LIFDCs) due to loss of trade, there would still be many famine deaths there. Many LIFDCs are in tropical regions too, where there is a smaller decrease in crop yields during a nuclear winter (see Fig. 4 of Xia 2022).
 

Another factor is that if countries are aware of the potential of scaling up resilient foods, they would be less likely to restrict trade. Therefore, I'm thinking the outcomes might be fairly bimodal, with one scenario of resilient food production and continued trade, and another scenario of not having resilient food production and loss of trade, potentially more than just food trade, perhaps with loss of industrial civilization or worse.
 

Yet, at least ignoring anthropics, I believe there would be a probability of full recovery of 100 % (= 1 - e^(-10^9/(66*10^6))) even then, assuming:

  • An exponential distribution for the time to go from i) human extinction due to such an asteroid to ii) evolving a species as capable as humans at steering the future, with mean equal to the aforementioned 66 M years.
  • The above evolution could take place in the next 1 billion years during which the Earth will remain habitable.

I think this assumes a scenario where, after the asteroid that causes human extinction, the next billion years are large asteroid/comet free, which is not a good assumption.

This was very helpful! I found the diagrams particularly useful. Visible lighting design for rooms has a similar problem of uniform illumination, but it is mitigated by the fact that there is significant reflection of the light, which I presume does not apply for far UVC. 
Has there been any work on planning to relocate existing UV systems to the most critical tasks, if an extreme pandemic hit soon, of making more super PPE/UV systems?

One unpublished study by a Russian academic and a CDC researcher allegedly estimated that the cost of 1 ACH by ventilation is about $135.91 USD and by GUV is about $14.44 USD.[131] 1DaySooner and Rethink Priorities have estimates that "The price of current systems is currently too high for at-scale deployment, though there are reasons to think the price can be lowered significantly;" they estimate that the cost of upgrading all U.S. buildings for improved indoor air quality would be about $120 billion - $420 billion.[132] 


The units do not appear to be complete - cost of 1 ACH for how big of space? Footnote 131 requires a password. Footnote 132 says “all public buildings in the US” not “all US buildings.” If public building is defined as this, I would guess that would control less than 10% of transmission in the US.


 

Why is flesh weaker than diamond?

I don't think this is a fair comparison. If nature wanted skin to be harder, it can do that, for instance with scales (particularly hard in the case of turtle shells). Of course your logic explains why diamond is harder than bone. But if you want a small thing that could penetrate flesh, we already have it in the form of parasites.

One of the points in the book Strangers Drowning was that very dedicated altruists (some EAs included) live like it is war time all the time. Basically, the urgency of people dying from poverty, animals suffering, and humanity's future at risk demand the sacrifices that are typically reserved for war time. Another example is if existential risk were high, some argue that we should be on "extreme war footing" and dedicate a large portion of society's resources to reducing the risk. I'm interested in your perspective on these thoughts.

Thanks for the correction! I have fixed it and added a link (the link was in the main document, but it's good to have it in the executive summary as well).

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.

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