That does seem high to me, though perhaps not ludicrously high. Past events have probably killed at least 10% of the global population, WWII was within an order of magnitude of that, and we’ve increased out warmaking capacity since then. So I think it would be reasonable to put that annual chance of a war killing at least 10% of the global population at at least 1%.
Note the 14.8 % I mentioned in my last comment refers to “the probability of a war causing human extinction conditional on it causing an annual population loss of at least 10 %”, not to the annual probability of a war causing a population loss of 10 %. I think 14.8 % for the former is super high[1], but I should note the Metaculus’ community might find it reasonable:
It is predicting:
A 5 % chance of a nuclear catastrophe causing a 95 % population loss conditional on it causing a population loss of at least 10 %.
A 10 % chance of a bio catastrophe causing a 95 % population loss conditional on it causing a population loss of at least 10 %.
I think a nuclear or bio catastrophe causing a 95 % population loss would still be far from causing extinction, so I could still belive the above suggest the probability of a nuclear or bio war causing extinction conditional on it causing a population loss of at least 10 % is much lower than 5 % and 10 %, and therefore much lower than 14.8 % too.
However, the Metaculus’ community may find extinction is fairly likely conditional on a 95 % population loss.
That could give some insight into the extinction tail, perhaps implying that my estimate was about 10x too high. That would still make it importantly wrong, but less egregiously than the many orders of magnitude you estimate in the main post?
Note “the probability of a war causing human extinction conditional on it causing an annual population loss of at least 10 %” increases quite superlinearly with the annual probability of a war causing human extinction (see graph in my last comment). So this will be too high by more than 1 OOM if the 14.8 % I mentioned is high by 1 OOM. To be precise, for the best fit distribution with a “probability of a war causing human extinction conditional on it causing an annual population loss of at least 10 %” of 1.44 %, which is roughly 1 OOM below 14.8 %, the annual probability of a war causing human extinction is 3.41*10^-7, i.e. 2.56 (= log10(1.24*10^-4/(3.41*10^-7))) OOMs lower. In reality, I suspect 14.8 % is high by many OOMs, so an astronomically low prior still seems reasonable to me.
I have just finished a draft where I get an insive view estimate of 5.53*10^-10 for the nearterm annual probability of human extinction from nuclear war, which is not too far from the best guess prior I present in the post of 6.36*10^-14. Comments are welcome, but no worries if you have other priorities! Update: I have now published the post.
I understand war extinction risk may be majorly driven by AI and bio risk rather than nuclear war. However, I have sense this is informed to a significant extent by Toby’s estimates for existential risk given in The Precipice, whereas I have found them consistently much higher than my estimates for extinction risk for the matters I have investigated. For example, in the draft I linked above, I say it is plausible extinction risk from nuclear war is similar to that from asteroids and comets.
Thanks for jumping in, Stephen!
Note the 14.8 % I mentioned in my last comment refers to “the probability of a war causing human extinction conditional on it causing an annual population loss of at least 10 %”, not to the annual probability of a war causing a population loss of 10 %. I think 14.8 % for the former is super high[1], but I should note the Metaculus’ community might find it reasonable:
It is predicting:
A 5 % chance of a nuclear catastrophe causing a 95 % population loss conditional on it causing a population loss of at least 10 %.
A 10 % chance of a bio catastrophe causing a 95 % population loss conditional on it causing a population loss of at least 10 %.
I think a nuclear or bio catastrophe causing a 95 % population loss would still be far from causing extinction, so I could still belive the above suggest the probability of a nuclear or bio war causing extinction conditional on it causing a population loss of at least 10 % is much lower than 5 % and 10 %, and therefore much lower than 14.8 % too.
However, the Metaculus’ community may find extinction is fairly likely conditional on a 95 % population loss.
Note “the probability of a war causing human extinction conditional on it causing an annual population loss of at least 10 %” increases quite superlinearly with the annual probability of a war causing human extinction (see graph in my last comment). So this will be too high by more than 1 OOM if the 14.8 % I mentioned is high by 1 OOM. To be precise, for the best fit distribution with a “probability of a war causing human extinction conditional on it causing an annual population loss of at least 10 %” of 1.44 %, which is roughly 1 OOM below 14.8 %, the annual probability of a war causing human extinction is 3.41*10^-7, i.e. 2.56 (= log10(1.24*10^-4/(3.41*10^-7))) OOMs lower. In reality, I suspect 14.8 % is high by many OOMs, so an astronomically low prior still seems reasonable to me.
I have just finished a draft where I get an insive view estimate of 5.53*10^-10 for the nearterm annual probability of human extinction from nuclear war, which is not too far from the best guess prior I present in the post of 6.36*10^-14. Comments are welcome, but no worries if you have other priorities! Update: I have now published the post.
I understand war extinction risk may be majorly driven by AI and bio risk rather than nuclear war. However, I have sense this is informed to a significant extent by Toby’s estimates for existential risk given in The Precipice, whereas I have found them consistently much higher than my estimates for extinction risk for the matters I have investigated. For example, in the draft I linked above, I say it is plausible extinction risk from nuclear war is similar to that from asteroids and comets.
I updated “quite high” in my last comment to “super high”.