I think this is too bearish on the economic modeling. If you want to argue that climate change could pose some risk of civilization collapse, you have to argue that some pathway exists from climate to a direct impact on society that prevents the society from functioning. When discussing collapse scenarios from climate most people (I think) are envisiging food, water, or energy production becoming so difficult that this causes further societal failures. But the economic models strongly suggest that the perturbations on these fronts are only “small”, so that we shouldn’t expect these to lead to a collapse. I think in this regime we should trust the economic modeling. If instead the economic models were finding really large effects (say, a 50% reduction in food production), then I would agree that the economic models were no longer reliable. At this point society would be functioning in a very different regime from present, so we wouldn’t expect the economic modeling to be very useful.
You could argue that the economic models are missing some other effect that could cause collapse, but I think it is difficult to tell such a story. The story that climate change will increase the number of wars is fairly speculative, and then you would have to argue that war could cause collapse, which is implausible excepting nuclear war. I think there is something to this story, but would be surprised if climate change were the predominant factor in whether we have a nuclear war in the next century.
Famine induced mass migration also seems very unlikely to cause civilization collapse. It would be very easy with modern technology for a wealthy country to defend itself against arbitrarily large groups of desperate, starving refuges. Indeed, to my knowledge there has been no analogy for a famine->mass migration->collapse of neighbouring society chain of events in the historic record, despite many horrific famines. I haven’t investigated this quesiton in detail however, and would be very interested if such events have in fact occurred.
Thanks for the perspective! I agree in part with your point about trusting the models while the perturbations they predict are small, but even then I’d say that there are two very different possibilities:
we can safely ignore real-world nonlinearities, cascading effects, etc., because the economic models suggest the perturbations are small.
the predicted perturbations are small because the economic models neglect key real-world nonlinearities and cascading effects.
As long as we think the second option is plausible enough, strong skepticism of the models remains justified. I don’t claim to know what’s actually the case here—this seems like a pretty important thing to work on understanding better.
I don’t understand 2. The neglected cascading effects have to cascade from somewhere. You are saying that the model could be missing an effect on the variables in its system from variables outside the system. But the variables outside the system you highlight are only going to be activated when the variables in the system are highly perturbed!
Forgetting the models for a second, if the only causal story to wars and mass migration that we can think of goes through high levels of economic disruption, then it is sufficient to see small levels of economic disruption and conclude that wars and mass migration are very unlikely.
I do not think that “small levels” is necessarily what we see—increased rates of natural disasters have really substantial effects on migration and could produce localized resource conflicts. But those don’t seem large scale enough to trigger global catastrophes.
I think this is too bearish on the economic modeling. If you want to argue that climate change could pose some risk of civilization collapse, you have to argue that some pathway exists from climate to a direct impact on society that prevents the society from functioning. When discussing collapse scenarios from climate most people (I think) are envisiging food, water, or energy production becoming so difficult that this causes further societal failures. But the economic models strongly suggest that the perturbations on these fronts are only “small”, so that we shouldn’t expect these to lead to a collapse. I think in this regime we should trust the economic modeling. If instead the economic models were finding really large effects (say, a 50% reduction in food production), then I would agree that the economic models were no longer reliable. At this point society would be functioning in a very different regime from present, so we wouldn’t expect the economic modeling to be very useful.
You could argue that the economic models are missing some other effect that could cause collapse, but I think it is difficult to tell such a story. The story that climate change will increase the number of wars is fairly speculative, and then you would have to argue that war could cause collapse, which is implausible excepting nuclear war. I think there is something to this story, but would be surprised if climate change were the predominant factor in whether we have a nuclear war in the next century.
Famine induced mass migration also seems very unlikely to cause civilization collapse. It would be very easy with modern technology for a wealthy country to defend itself against arbitrarily large groups of desperate, starving refuges. Indeed, to my knowledge there has been no analogy for a famine->mass migration->collapse of neighbouring society chain of events in the historic record, despite many horrific famines. I haven’t investigated this quesiton in detail however, and would be very interested if such events have in fact occurred.
Thanks for the perspective! I agree in part with your point about trusting the models while the perturbations they predict are small, but even then I’d say that there are two very different possibilities:
we can safely ignore real-world nonlinearities, cascading effects, etc., because the economic models suggest the perturbations are small.
the predicted perturbations are small because the economic models neglect key real-world nonlinearities and cascading effects.
As long as we think the second option is plausible enough, strong skepticism of the models remains justified. I don’t claim to know what’s actually the case here—this seems like a pretty important thing to work on understanding better.
I don’t understand 2. The neglected cascading effects have to cascade from somewhere. You are saying that the model could be missing an effect on the variables in its system from variables outside the system. But the variables outside the system you highlight are only going to be activated when the variables in the system are highly perturbed!
Forgetting the models for a second, if the only causal story to wars and mass migration that we can think of goes through high levels of economic disruption, then it is sufficient to see small levels of economic disruption and conclude that wars and mass migration are very unlikely.
I do not think that “small levels” is necessarily what we see—increased rates of natural disasters have really substantial effects on migration and could produce localized resource conflicts. But those don’t seem large scale enough to trigger global catastrophes.