Hi Dan. I expect terrorist attacks to be super unlikely to cause human extinction in the absence of very strong evidence suggesting otherwise. For the attacks killing more than 10 people among the 202 k listed on the Global Terrorism Database (GTB), the fraction killing more than 10*N people is around 1 % of the fraction killing more than N people. This suggests a Pareto distribution with a tail index of 2. Around 0.001 % of attacks killed more than 1 k people. Assuming the same Pareto distribution (straight line fitted to the section of the graph below with more than 10 deaths), more than 1 billion deaths would be 10^-12 (= 0.01^(9 - 3)) times as likely as more than 1 k deaths. So the Pareto distribution implies only 10^-17 (= 10^(-5 - 12)) of terrorist attacks cause more than 1 billion deaths. I think the actual risk is way higher. At the same time, I believe a significant risk of a terrorist attack causing human extinction, like 1 % over the next 20 years, would depart a lot from the most natural uninformed ways of extrapolating past data. A pandemic causing human extinction looks much more plausible based on past data (although I still guess the risk of human extinction in the next 20 years is much lower than 1 %).

Hi Marcus and Jim. Great post. I agree. I also liked the direct writing style.

Hi Liam. Nice post. You may be interested in this linkpost for the article "The Conscious Nematode: Exploring Hallmarks of Minimal Phenomenal Consciousness in Caenorhabditis Elegans".

And given the sheer number of soil nematodes — some researchers estimate there may be over 10^20 of them, or more than a million million million nematodes! — that means their aggregate welfare could be extremely large, possibly larger than all other animals on Earth.

Here are illustrations of the above.

In this post, "welfare range as a fraction of that of humans" means "individual welfare per fully-healthy-animal-year as a fraction of the welfare per fully-healthy-human-year".

I don't think you can extrapolate standard population models past the invention of artificial wombs and robo-nannies. The "Recovery" premise is much more plausible if creating new lives is less personally costly.

Why would artificial wombs and robo-nannies have very different effects from other innovations that have decreased the time cost of having children (for example, washing machines), or increased the income of prospective parents (for example, increasing income of women)? A lower cost of having children as a fraction of available income would increase fertility if the cost of everything else remained the same, but alternatives would become cheaper too relative to available income. It is unclear to me whether your point strengthens or weakens the conclusions of Alexandrie and Eden (2025) under the population models they analysed.

That makes sense.

Hi Mal.

• Drone replacements for pollination services. Bring down the cost of micro-drones that can pollinate almond trees down to be cost-competitive with bee-based pollination services, potentially ending an industry that harms billions of bees each year.

Are you assuming the bees would prefer not existing? I suppose this is very uncertain.

Hi Richard.

Of course, one could always try to argue on the merits that standard EA views on both global poverty and AI safety are empirically mistaken. That’s fine. All I’m saying here is that one had better not endorse higher-level heuristics, applied prior to any engagement with the specific details, that rule out both rigorously-supported global health charities (simply for being insufficiently ambitious) and speculative longtermist longshots (simply for being insufficiently rigorous). After all, if you prioritize rigor, the prima facie case for global health charities is going to be hard to beat. And if you prioritize reach (potential impact), nobody else is even in the same ballpark as the longtermists.

Are you confident the longtermist interventions you have in mind, like work on AI safety, are more cost-effective accounting for longterm effects than global health interventions? Decreasing the risk of human extinction may be less cost-effective than global health interventions accounting for longterm effects hold under standard population models. So it is unclear to me whether there is the rigor-reach dilemma you describe.

I can even see global health interventions decreasing nearterm extinction risk more cost-effectively than AI safety interventions. I am not aware of any quantitative modelling comparing both options.

Relatedly, I liked the post by 50 things I know by Cate Hall.

As I understand your view, something is good if you prefer it and don't expect that preference to change on reflection. That makes "good" relative to each person.

Right. I would just replace "something is good if you prefer it" with "something being morally good means (under your definition) you prefer it". Many people define "morally good" differently, and definitions are not right or wrong, although they can be more or less in agreement with common usage of the words involved. One should just be clear about definitions to avoid confusion, and not pick definitions which are super far from common usage (like defining "good" as something that is strongly dispreferred, which would easily lead to confusion).

That makes "good" relative to each person. So imagine someone who says: "I like eating chickens from factory farms, and I fully expect to keep liking it." By your definition, factory farming is good for them and bad for you, and that's the end of the discussion.

Nitpick. I have little idea if eating chicken increaes or decreases welfare. So it is unclear to me whether it is good or bad.

Someone thinking eating chicken is morally good or bad (under my definitions of these terms) would not necessarily be the end of the discussion. They could be wrong about how their preferences would evolve given new information. They could be very confident chickens do not feel pain, and that they would also not care about decreasing the pain of chickens anyway, but change their minds after investigating the biology and behaviour of chickens, and wacthing footage of broiler farms.

Why should they care about your preference, any more than you should care about theirs?

They may care more about my preferences if their preferences have been approaching my preferences. Say they initially did not care at all about chickens, but now care about them as I predicted they would if they reflected on it. Suppose they still do not care about fishes. They may trust themselves less than in the past. They may know they were wrong about which preferences about chickens they would have on reflection, that I correctely predicted how their preferences about chickens would evolve, and that I care about fishes.

Some people could continue not caring at all about farmed animals after going through all the relevant evidence. However, I believe they would be a very small fraction of the population, and I do not think engaging with them would be a cost-effective way of increasing the welfare of farmed animals.

You said long-term outcomes don't have to be good, but on your view that only means they don't have to be good by your lights.

Right.

What would make the majority wrong, rather than just different from you?

The majority could be morally wrong by their own lights due to not accurately predicting how their preferences would evolve if they reflected more them. Assuming their preferences were very stable, they would be morally right by their own lights, but they would still be morally wrong by my own lights, by which I just mean their preferences on reflection would differ from mine. I understand many people define "morally wrong" differently.

And a related question: chickens and shrimp aren't moral agents. Do their interests count in themselves on your view, or only because moral agents like you happen to care about them?

I would still want chickens and shrimps (and any other organisms) to satisfy their preferences if there were no moral agents.