The more severe scenarios modelled in Xia 2022 are very unlikely given my soot injected into the stratosphere per countervalue detonation of 0.0491 Tg, which I got giving the same weight to the results I inferred for Reisner’s and Toon’s views on the soot injected into the stratosphere per countervalue yield. Assuming 22.1 % of offensive nuclear detonations are countervalue regardless of the total number of detonations, my probabilities for an injection of soot into the stratosphere at least as large as the reference values in Xia 2022, owing to a nuclear war before 2050, are as follows[1]. For at least:
5 Tg, i.e. 102 (= 5/0.0491) countervalue nuclear detonations, corresponding to 462 (= 102/0.221) offensive nuclear detonations, 6.54 %.
16 Tg, i.e. 326 (= 16/0.0491) countervalue nuclear detonations, corresponding to 1.48 k (= 326/0.221) offensive nuclear detonations, 2.18 %.
27 Tg, i.e. 550 (= 27/0.0491) countervalue nuclear detonations, corresponding to 2.49 k (= 550/0.221) offensive nuclear detonations, 0.843 %.
37 Tg, i.e. 754 (= 37/0.0491) countervalue nuclear detonations, corresponding to 3.41 k (= 754/0.221) offensive nuclear detonations, 0.346 %.
47 Tg, i.e. 957 (= 47/0.0491) countervalue nuclear detonations, corresponding to 4.33 k (= 957/0.221) offensive nuclear detonations, 0.130 %.
150 Tg, i.e. 3.05 k (= 150/0.0491) countervalue nuclear detonations, corresponding to 13.8 k (= 3.05*10^3/0.221) offensive nuclear detonations, 0. In reality, the probability is not null, as there may be more than 22.1 % of offensive nuclear detonations being countervalue, and the number of nuclear warheads available can also be higher than my expectation of 9.43 k. Maintaining this, but assuming 50 % of offensive nuclear detonations would be countervalue, there would be 6.10 k (= 3.05*10^3/0.5) offensive nuclear detonations, and the probability of more than 150 Tg would be 0.0123 %.
For reference, I expect 342 offensive nuclear detonations given one before 2050, corresponding to 75.6 (= 342*0.221) countervalue nuclear detonations, and 3.71 Tg (= 75.6*0.0491). One may argue this is too small given the possibility of worst case scenarios, but my expected severity of the climatic effects of nuclear war is already driven by worst case scenarios. For my median 35.1 offensive nuclear detonations given one before 2050, corresponding to 7.76 (= 35.1*0.221) countervalue nuclear detonations, I would only expect 0.381 Tg (= 7.76*0.0491), i.e. 10.3 % (= 0.381/3.71) as much as the value I got for my expected detonations.
The more severe scenarios modelled in Xia 2022 are very unlikely given my soot injected into the stratosphere per countervalue detonation of 0.0491 Tg, which I got giving the same weight to the results I inferred for Reisner’s and Toon’s views on the soot injected into the stratosphere per countervalue yield. Assuming 22.1 % of offensive nuclear detonations are countervalue regardless of the total number of detonations, my probabilities for an injection of soot into the stratosphere at least as large as the reference values in Xia 2022, owing to a nuclear war before 2050, are as follows[1]. For at least:
5 Tg, i.e. 102 (= 5/0.0491) countervalue nuclear detonations, corresponding to 462 (= 102/0.221) offensive nuclear detonations, 6.54 %.
16 Tg, i.e. 326 (= 16/0.0491) countervalue nuclear detonations, corresponding to 1.48 k (= 326/0.221) offensive nuclear detonations, 2.18 %.
27 Tg, i.e. 550 (= 27/0.0491) countervalue nuclear detonations, corresponding to 2.49 k (= 550/0.221) offensive nuclear detonations, 0.843 %.
37 Tg, i.e. 754 (= 37/0.0491) countervalue nuclear detonations, corresponding to 3.41 k (= 754/0.221) offensive nuclear detonations, 0.346 %.
47 Tg, i.e. 957 (= 47/0.0491) countervalue nuclear detonations, corresponding to 4.33 k (= 957/0.221) offensive nuclear detonations, 0.130 %.
150 Tg, i.e. 3.05 k (= 150/0.0491) countervalue nuclear detonations, corresponding to 13.8 k (= 3.05*10^3/0.221) offensive nuclear detonations, 0. In reality, the probability is not null, as there may be more than 22.1 % of offensive nuclear detonations being countervalue, and the number of nuclear warheads available can also be higher than my expectation of 9.43 k. Maintaining this, but assuming 50 % of offensive nuclear detonations would be countervalue, there would be 6.10 k (= 3.05*10^3/0.5) offensive nuclear detonations, and the probability of more than 150 Tg would be 0.0123 %.
For reference, I expect 342 offensive nuclear detonations given one before 2050, corresponding to 75.6 (= 342*0.221) countervalue nuclear detonations, and 3.71 Tg (= 75.6*0.0491). One may argue this is too small given the possibility of worst case scenarios, but my expected severity of the climatic effects of nuclear war is already driven by worst case scenarios. For my median 35.1 offensive nuclear detonations given one before 2050, corresponding to 7.76 (= 35.1*0.221) countervalue nuclear detonations, I would only expect 0.381 Tg (= 7.76*0.0491), i.e. 10.3 % (= 0.381/3.71) as much as the value I got for my expected detonations.
Calculated here from 0.32*(1 - beta.cdf(“offensive nuclear detonations”/(9.43*10**3), alpha, beta_)).