Your probability analysis excludes some high quality work (such as peer reviewed publications) which have a higher probability of nuclear conflict, potentially at 1% annually.
To clarify, CEARCH’s estimated a probability of a conflict involving at least 100 nuclear detonations in the US, Russia or China of 0.0991 % per year, which is 9.91 % of the 1 % you mention. However, this refers to the probability of nuclear launch:
The US or Russia launching a nuclear weapon does not have to lead to 100 nuclear detonations in the US, China and Russia. The US or Russia could be attacking other countries, or the nuclear conflict fall short of escalating to at least 100 nuclear detonations. So I do not think the above estimates are obviously at odds with CEARCH’s.
The threshold for a catastrophic nuclear war in the XPT was very high—causing at least 10% of humanity to die over 5 years or less—and so should be considered as the probability of a nuclear conflict killing at least 800 million people, rather than a nuclear exchange.
I think the median particpant of The Existential Risk Persuasion Tournament (XPT) is very pessimistic about nuclear risk. The annual nuclear extinction risk from 2023 to 2050 respecting the median superforecaster and expert is 602 k and 7.23 M times mine of 5.93*10^-12.
It is also worth noting XPT’s forecasters varied a lot in their predictions. 6.21 % (10/161) forecasted a nuclear extinction risk from 2023 to 2100 of exactly 0 (which is obviously too low and wrong, but still illustrates my point).
ALLFED’s estimate suggest dividing by 46.9 (= 1⁄0.0213)?
David Denkenberger (ALLFED’s co-founder and research director)modelled the “percent of combustible material that burns that turns into soot” as a lognormal distribution with 2.5th and 97.5th percentiles equal to 1 % and 4 % (see Table 2), whose mean is 2.13 %.
Reisner 2018 consider the above fraction to be 1 (emphasis mine):
“Further, because the current version of FIRETEC assumes BC production to be inversely proportional to oxygen depletion (no soot model was employed), that is, all the carbon in the fuel participated in the reaction and was turned into BC, the estimates, which represent upper bounds for the given fuel loadings, are higher (worst case) than they would be if a detailed chemical combustion model was used for soot production”.
For readers’ reference, I have explained why I think Mike’s nuclear winter analysis is too pessimistic.
Hi Mike,
To clarify, CEARCH’s estimated a probability of a conflict involving at least 100 nuclear detonations in the US, Russia or China of 0.0991 % per year, which is 9.91 % of the 1 % you mention. However, this refers to the probability of nuclear launch:
The US or Russia launching a nuclear weapon does not have to lead to 100 nuclear detonations in the US, China and Russia. The US or Russia could be attacking other countries, or the nuclear conflict fall short of escalating to at least 100 nuclear detonations. So I do not think the above estimates are obviously at odds with CEARCH’s.
I think the median particpant of The Existential Risk Persuasion Tournament (XPT) is very pessimistic about nuclear risk. The annual nuclear extinction risk from 2023 to 2050 respecting the median superforecaster and expert is 602 k and 7.23 M times mine of 5.93*10^-12.
It is also worth noting XPT’s forecasters varied a lot in their predictions. 6.21 % (10/161) forecasted a nuclear extinction risk from 2023 to 2100 of exactly 0 (which is obviously too low and wrong, but still illustrates my point).
ALLFED’s estimate suggest dividing by 46.9 (= 1⁄0.0213)?
David Denkenberger (ALLFED’s co-founder and research director) modelled the “percent of combustible material that burns that turns into soot” as a lognormal distribution with 2.5th and 97.5th percentiles equal to 1 % and 4 % (see Table 2), whose mean is 2.13 %.
Reisner 2018 consider the above fraction to be 1 (emphasis mine):
“Further, because the current version of FIRETEC assumes BC production to be inversely proportional to oxygen depletion (no soot model was employed), that is, all the carbon in the fuel participated in the reaction and was turned into BC, the estimates, which represent upper bounds for the given fuel loadings, are higher (worst case) than they would be if a detailed chemical combustion model was used for soot production”.
For readers’ reference, I have explained why I think Mike’s nuclear winter analysis is too pessimistic.