Thanks for the post. The updated nuclear winter modeling is Coupe 2019 - it has similar results to the 2007 work. The new work was funded by Open Phil. I agree that extinction is quite unlikely, but I think there are a few routes to get there. Many people mention the lower climate impacts in places like New Zealand, but they do not consider the possibility of refugees overwhelming New Zealand. You may very well be right that some food storage will be protected, but I don’t think it’s guaranteed that people could or would forcibly repel the desperate people trying to get food. Furthermore, if there is an eventual collapse of anthropological civilization (cooperation outside tribes), we may have to go back to hunting and gathering, and there is evidence that that transition may not go well (The Secret of Our Success book). And the current hunter gatherers generally don’t have much food storage, so they would likely die out.
But then I agree with Max Daniel that even if extinction is unlikely, I think worse trajectory changes have significant probability, which is supported by the poll of GCR researchers here.
As Robock points out, even without firestorms (simultaneous burning of a large area), some smoke can go into the upper troposphere and be lofted into the stratosphere. Indeed, this has been demonstrated for wildfires (which are not firestorms).
Thanks for the post. The updated nuclear winter modeling is Coupe 2019 - it has similar results to the 2007 work. The new work was funded by Open Phil. I agree that extinction is quite unlikely, but I think there are a few routes to get there. Many people mention the lower climate impacts in places like New Zealand, but they do not consider the possibility of refugees overwhelming New Zealand. You may very well be right that some food storage will be protected, but I don’t think it’s guaranteed that people could or would forcibly repel the desperate people trying to get food. Furthermore, if there is an eventual collapse of anthropological civilization (cooperation outside tribes), we may have to go back to hunting and gathering, and there is evidence that that transition may not go well (The Secret of Our Success book). And the current hunter gatherers generally don’t have much food storage, so they would likely die out.
But then I agree with Max Daniel that even if extinction is unlikely, I think worse trajectory changes have significant probability, which is supported by the poll of GCR researchers here.
As Robock points out, even without firestorms (simultaneous burning of a large area), some smoke can go into the upper troposphere and be lofted into the stratosphere. Indeed, this has been demonstrated for wildfires (which are not firestorms).