In particular, climate economy models still do bad at the heavy tail, not just of warming, but at civilisational vulnerability etc, again presenting a pretty “middle of the road” rather than heavy tailed distribution. The sort of work from Beard et al 2021 for instance highlights something I think the models pretty profoundly miss. Similarly, I’d be really interested in research similar to Mani et al 2021 on extreme weather events and how this may change due to climate change.
I dpon’t see why the models discount the idea that there is a low but non-negligable probability of catastrophic consequences from 3-4 degrees of warming. What aspect of the models? I’m reticent to rely on things like damage functions here, as they don’t seem to engage with the possib;le heavy-tailedness of damage. Whilst I agree that the models probably are decent approximations of reality, I’m just not really very sure they are useful at telling us anything about the low probabil;ity high impact scenarios that we are worried about here.
Whilst I agree there are reasons to think our vulnerability is less, there is clear reasons to think with a growing interconnected (and potentially fragile) global network and economy, our vulnerability is increasing, meaning that whilst the past collapse data might not be prophetic, there is at least value in it; after all, we are in a very evidence poor environment, meaning that I would be reticent to dismiss it as strongly as you seem to. And whilst it is true our agricultural system is more resilient, there is still a possibility of multiple breadbasket failures etc caused by climate change, and the beard et al and richards et al both explore plausible pathways to this. Again, whilst the past collapse data is definitely not a slam dunk in my favour, I would at least argue it is an update nonetheless. I think you might argue the fact that none led to human extinction makes that data an update in yopur direction, and i think your view on this depends on whether you see collapse and GCR and extinction on a continuum or not; I broadly do, and I assume you broadly don’t?
When I said one data point, I meant really one study. The reason I say this, is as cited, studies of different species/ species groups. In your comment, you don’t seem to engage with Song et al 2021. Kaiho at al 2022 also shows a positive relationship between warming and extinction rate. Moreover, I think it takes an overly confident view of our understanding of kill mechanisms, and seems to suggest that just because we don’t have all what you speculate were the important factors that were present in past mass extinctions doesn’t make that not useful evidence. I think a position like Keller et al 2018 (PETM as the best case, KPg as the worst case) is probably useful at looking at this (only using modern evidence!). Once again, this is an attempt by me, in a low evidence situation, to make best use of the evidence available, and I don’t find your points compelling enough to make me not think that this past precident can’t be informative.
On the Planetary Boundaries, you don’t seem to be engaging with what I’m saying here, which is most alluding to the Baum et al paper on this. Moreover, even if you think we are to use EV, what are you basing the probabilities on? I assume some sort of subjective bayesianism, in which case you’ll have to tell me why I should put a decently high (>1%) prior on moving beyond certain Holocene boundaries posing a genuine threat to humanity? That seems perfectly reasonable to me
I’m not really sure I understand the argument? Whilst in some ways the world has indeed got less vulnerable, in other ways it has got more connected, more economically vulnerable to natural disasters etc. Cascading impact seems to be seen more along these lines than along others. Moreover, if you only had a 5% probability of such a cascade occuring over a century, and we have hardly had a hyper-globalised economy for even that long, why would you expect it to have happened already? Your statements here seem pretty out of step with my actual probabilities etc.. And as I talk about in my talk, I also see problems from AI, biorisk and a whole host more. Thats why this talk, and this approach, is seriously not just about climate change; the hope is to add another approach to studying X-Risk.
I’m also pretty interested in your approach to evidence on X-Risk. I should say from the outset that I think climate change is unlikely to cause a catastrophe, but I don’t think you have provided compelling evidence that the probability is exceptionally small. Your evidence often seems to rely on the very things that we think ought to be suspect in X-Risk scenarios (economic models, continued improved resilience, best case scenario analogies etc.), and you seem to reject some things that might be useful for reasoning in such evidence poor environments (plausibly useful but somewhat flawed historical analogies, foresight, storytelling, scenarios etc.) . Basically, you seem to have a pretty high bar for evidence to be worried about climate change, which whilst I in general think is useful, I’m just not sure how appropriate it is in such an evidence poor environment as X-Risk, including climate change contributions to it. Its pretty interesting that you seem very willing to rely on much more speculative evidence for AI and biorisk (eg probabilistic forecasts which don’t have track records of being able to work well over such long time scales), and I genuinely wonder why this is. Note that such more speculative approaches (in this case superforecasters) gave a 1% probability of climate change being a necessary but not sufficent cause of human extinction by 2100, and gave an even higher probability to global catastrophe by 2100, which certainly then has the probability of later leading to extinction. Whilst I myself am somewhat sceptical of such approaches, I’d be interested in seeing why you seem accepting of them for bio and AI but not climate? Is it because you see evaluation of the existential risk from climate change as a much more evidence rich environment than for bio/AI?
I’m not sure they’re middle of the road on civilisational vulnerability. It would be pretty surprising if extreme weather events made a big difference to the overall picture. For the kinds of extreme weather events one sees in the literature, it’s just not a big influence on global GDP. How bad would a hurricane or flood have to be to push things from ‘counterfactual GDP reduction of 5%’ to civilisational collapse.
I don’t think they fully discount/ignore the possibility of catastrophe 3/4ºC. In part this is just an outcome of the models and of the scientific literature. There are no impacts that come close to catastrophe in the scientific literature for 3/4ºC. I agree they miss some tipping points, but looking at the scientific literature on that, it’s hard to see how it would make a big difference to the overall picture.
I haven’t read those papers and don’t have time to do so now unfortunately. My argument there doesn’t rely on one study but on a range of studies in the literature for different warm periods. The Permian was a very extreme and unusual case because it caused such massive land-based extinctions, which was caused by the release of halogens, which is not relevant to future climate change. Also, both the Permian and PETM were extremely hot relative to what we now seem to be in for (17ºC vs 2.5ºC).
I’m not sure I see how I am not engaging with you on planetary boundaries. I thought we were disagreeing about whether to put weight on planetary boundaries, and I was arguing that the boundaries just seem made up. Using EV may have its own problems but that doesn’t make planetary boundaries valid.
I don’t really see how the world now is more vulnerable to any form of weather events in any respect than it has been at any other point in human history. Society routinely absorbs large bad weather events; they don’t even cause local civilisational collapse any more (in middle and high income countries). Deaths from weather disasters have declined dramatically over the last 100 or so years, which is pretty strong evidence that societal resilience is increasing not decreasing. In the pre-industrial period, all countries suffered turmoil and hunger due to cold and droughts. This doesn’t happen any more in countries that are sufficiently wealthy. Many countries now suffer drought, almost entirely due to implicit subsidies for agricultural water consumption. It is very hard to see how this could lead to eg to collapse in California or Spain.
Can you set out an example of a cascading causal process that would lead to a catastrophe?
I’m not sure that there is some meta-level epistemic disagreement, I think we just disagree about what the evidence says about the impacts of climate change. In 2016, I was much more worried than the average FHI person about climate change, but after looking at the impacts literature and recent changes in likely emissions, I updated towards climate change being a relatively minor risk. Comparing to bio for instance, after reading about trends in gene synthesis technologies and costs, it takes about 30 minutes to see how it poses a major global catastrophic risk in the coming decades. I’ve been researching climate change for six years and struggle to see it. I am not being facetious here, this is my honest take.
Hi John, sorry this has taken a while.
In particular, climate economy models still do bad at the heavy tail, not just of warming, but at civilisational vulnerability etc, again presenting a pretty “middle of the road” rather than heavy tailed distribution. The sort of work from Beard et al 2021 for instance highlights something I think the models pretty profoundly miss. Similarly, I’d be really interested in research similar to Mani et al 2021 on extreme weather events and how this may change due to climate change.
I dpon’t see why the models discount the idea that there is a low but non-negligable probability of catastrophic consequences from 3-4 degrees of warming. What aspect of the models? I’m reticent to rely on things like damage functions here, as they don’t seem to engage with the possib;le heavy-tailedness of damage. Whilst I agree that the models probably are decent approximations of reality, I’m just not really very sure they are useful at telling us anything about the low probabil;ity high impact scenarios that we are worried about here.
Whilst I agree there are reasons to think our vulnerability is less, there is clear reasons to think with a growing interconnected (and potentially fragile) global network and economy, our vulnerability is increasing, meaning that whilst the past collapse data might not be prophetic, there is at least value in it; after all, we are in a very evidence poor environment, meaning that I would be reticent to dismiss it as strongly as you seem to. And whilst it is true our agricultural system is more resilient, there is still a possibility of multiple breadbasket failures etc caused by climate change, and the beard et al and richards et al both explore plausible pathways to this. Again, whilst the past collapse data is definitely not a slam dunk in my favour, I would at least argue it is an update nonetheless. I think you might argue the fact that none led to human extinction makes that data an update in yopur direction, and i think your view on this depends on whether you see collapse and GCR and extinction on a continuum or not; I broadly do, and I assume you broadly don’t?
When I said one data point, I meant really one study. The reason I say this, is as cited, studies of different species/ species groups. In your comment, you don’t seem to engage with Song et al 2021. Kaiho at al 2022 also shows a positive relationship between warming and extinction rate. Moreover, I think it takes an overly confident view of our understanding of kill mechanisms, and seems to suggest that just because we don’t have all what you speculate were the important factors that were present in past mass extinctions doesn’t make that not useful evidence. I think a position like Keller et al 2018 (PETM as the best case, KPg as the worst case) is probably useful at looking at this (only using modern evidence!). Once again, this is an attempt by me, in a low evidence situation, to make best use of the evidence available, and I don’t find your points compelling enough to make me not think that this past precident can’t be informative.
On the Planetary Boundaries, you don’t seem to be engaging with what I’m saying here, which is most alluding to the Baum et al paper on this. Moreover, even if you think we are to use EV, what are you basing the probabilities on? I assume some sort of subjective bayesianism, in which case you’ll have to tell me why I should put a decently high (>1%) prior on moving beyond certain Holocene boundaries posing a genuine threat to humanity? That seems perfectly reasonable to me
I’m not really sure I understand the argument? Whilst in some ways the world has indeed got less vulnerable, in other ways it has got more connected, more economically vulnerable to natural disasters etc. Cascading impact seems to be seen more along these lines than along others. Moreover, if you only had a 5% probability of such a cascade occuring over a century, and we have hardly had a hyper-globalised economy for even that long, why would you expect it to have happened already? Your statements here seem pretty out of step with my actual probabilities etc.. And as I talk about in my talk, I also see problems from AI, biorisk and a whole host more. Thats why this talk, and this approach, is seriously not just about climate change; the hope is to add another approach to studying X-Risk.
I’m also pretty interested in your approach to evidence on X-Risk. I should say from the outset that I think climate change is unlikely to cause a catastrophe, but I don’t think you have provided compelling evidence that the probability is exceptionally small. Your evidence often seems to rely on the very things that we think ought to be suspect in X-Risk scenarios (economic models, continued improved resilience, best case scenario analogies etc.), and you seem to reject some things that might be useful for reasoning in such evidence poor environments (plausibly useful but somewhat flawed historical analogies, foresight, storytelling, scenarios etc.) . Basically, you seem to have a pretty high bar for evidence to be worried about climate change, which whilst I in general think is useful, I’m just not sure how appropriate it is in such an evidence poor environment as X-Risk, including climate change contributions to it. Its pretty interesting that you seem very willing to rely on much more speculative evidence for AI and biorisk (eg probabilistic forecasts which don’t have track records of being able to work well over such long time scales), and I genuinely wonder why this is. Note that such more speculative approaches (in this case superforecasters) gave a 1% probability of climate change being a necessary but not sufficent cause of human extinction by 2100, and gave an even higher probability to global catastrophe by 2100, which certainly then has the probability of later leading to extinction. Whilst I myself am somewhat sceptical of such approaches, I’d be interested in seeing why you seem accepting of them for bio and AI but not climate? Is it because you see evaluation of the existential risk from climate change as a much more evidence rich environment than for bio/AI?
I’m not sure they’re middle of the road on civilisational vulnerability. It would be pretty surprising if extreme weather events made a big difference to the overall picture. For the kinds of extreme weather events one sees in the literature, it’s just not a big influence on global GDP. How bad would a hurricane or flood have to be to push things from ‘counterfactual GDP reduction of 5%’ to civilisational collapse.
I don’t think they fully discount/ignore the possibility of catastrophe 3/4ºC. In part this is just an outcome of the models and of the scientific literature. There are no impacts that come close to catastrophe in the scientific literature for 3/4ºC. I agree they miss some tipping points, but looking at the scientific literature on that, it’s hard to see how it would make a big difference to the overall picture.
I haven’t read those papers and don’t have time to do so now unfortunately. My argument there doesn’t rely on one study but on a range of studies in the literature for different warm periods. The Permian was a very extreme and unusual case because it caused such massive land-based extinctions, which was caused by the release of halogens, which is not relevant to future climate change. Also, both the Permian and PETM were extremely hot relative to what we now seem to be in for (17ºC vs 2.5ºC).
I’m not sure I see how I am not engaging with you on planetary boundaries. I thought we were disagreeing about whether to put weight on planetary boundaries, and I was arguing that the boundaries just seem made up. Using EV may have its own problems but that doesn’t make planetary boundaries valid.
I don’t really see how the world now is more vulnerable to any form of weather events in any respect than it has been at any other point in human history. Society routinely absorbs large bad weather events; they don’t even cause local civilisational collapse any more (in middle and high income countries). Deaths from weather disasters have declined dramatically over the last 100 or so years, which is pretty strong evidence that societal resilience is increasing not decreasing. In the pre-industrial period, all countries suffered turmoil and hunger due to cold and droughts. This doesn’t happen any more in countries that are sufficiently wealthy. Many countries now suffer drought, almost entirely due to implicit subsidies for agricultural water consumption. It is very hard to see how this could lead to eg to collapse in California or Spain.
Can you set out an example of a cascading causal process that would lead to a catastrophe?
I’m not sure that there is some meta-level epistemic disagreement, I think we just disagree about what the evidence says about the impacts of climate change. In 2016, I was much more worried than the average FHI person about climate change, but after looking at the impacts literature and recent changes in likely emissions, I updated towards climate change being a relatively minor risk. Comparing to bio for instance, after reading about trends in gene synthesis technologies and costs, it takes about 30 minutes to see how it poses a major global catastrophic risk in the coming decades. I’ve been researching climate change for six years and struggle to see it. I am not being facetious here, this is my honest take.