Thanks for sharing, Pablo. I had listened to that podcast discussing The Existential Risk Persuasion Tournament (XPT), but what I take from this is that there is huge dispersion in the extinction risk predictions. 

In addition, many forecasters predicted a probability of human extinction from 2023 to 2100 of exactly 0:

• For extinction, 3.18 % (5/157).
• For AI extinction, 4.29 % (7/163).
• For nuclear extinction, 6.21 % (10/161).
• Non-anthropogenic extinction excluding non-anthropogenic pathogens, 5.66 % (9/159).

A risk of exactly 0 is obviously wrong, but goes to show there are superforecasters and domain experts guessing the risk of human extinction is negligible. You can also qualitatively appreciate this from some comments in Appendix 7 of the report. Here are some I collected about the risk of nuclear extinction (emphasis mine):

• “Most forecasters whose probabilities were near the median factored in a range of possible risks, including world wars, nuclear winters, and even artificial-intelligence-driven NERs [nuclear extinction risks], but concluded that even under worst case scenarios, the extinction of humanity (give or take 5000 people) would be near impossible...even if an NER [nuclear existential risk] had set humanity on a path that made eventual extinction a foregone conclusion, existing resources on earth would allow at least 5000 survivors to hang on for seventy-eight years”.
• “For many, the thought of getting to less than 5000 humans alive was simply too far fetched an outcome and they couldn't be persuaded otherwise in what they saw as credible scenarios”.
• “[T]he set of circumstances required for this to happen are quite low, though obviously not impossible. These circumstances are that there will be a nuclear conflict between 2 nations both capable and willing to fire at everyone everywhere between the two of them: 'very bad case scenarios' where India and Pakistan, or the US and Russia, or China and anyone else, fired everything they had at just each other, or even at each other and each other's close allies, would likely not cause extinction…it requires some of the big nuclear powers to decide to try to take literally everyone down with them, and that they actually succeed”.
• “So we think that the probabilities in this question are dominated by scenarios of total nuclear war before 2050 which cause civilizational and climate collapse to the point where long-term survival becomes impossible to save for very well-prepared shelters. But even pessimistic scenarios seem unlikely to lead to a collapse that is fast enough to reduce the global population to below 5000 by 2100”.
• “There aren't compelling arguments on the higher end for this question again due to the fact that this is a very high bar to achieve”.
• “The team predicts that there will be pockets of people who survive in various regions of the world. Their survival may be at Neolithic standards, but there will be tribes of people who band together and restart mankind. After all, many mammals survived the asteroid and ice age that killed the dinosaurs”.
• “[A] certain number of team members feel that even if there was a full strategic exchange and usage of all of the world's nuclear arsenal still humanity would be able to keep its numbers over 5000. The argument for this is the number [a]nd population of uncontacted tribes, or isolated human populations like the Easter island population pre-contact, that have managed to hold numbers of over 5000 in extremely harsh conditions”.
• “[A]lmost certainly some people would survive on islands or in caves given even the worst of worst cases”.
• “Southern Hemisphere likely to be less impacted – New Zealand, Madagascar, Pacific Islands, Highlands of Papua New Guinea, unlikely to be targeted and include areas with little global and technology dependence…Just the population of Antarctica in its summer is ~5000 people. Even small islands surviving could easily mean more than 5k people”.
• “[There are s]everal regions in the world that would not be affected by nuclear conflict directly and have decent climatic conditions to support 100 of millions even in a NW [nuclear winter]”.