I really like the writing and material in this post. :) Have you considered the possibility that global warming may introduce instability that could exacerbate other potential conflicts, leading to potential existential crises from nuclear war? Perhaps this is too indirect and unlikely, but my understanding is that EAs that worry about climate change as an x-risk envision this kind of two-step x-risk scenario.
One terminology for this is introduced in “Governing Boring Apocalypses”, a recent x-risk paper. They call direct bad things like nuclear war an “existential harm”, but note that two other key ingredients are necessary for existential risk: existential vulnerability (reasons we are vulnerable to a harm) and existential exposure (ways those vulnerabilities get exposed). I don’t fully understand the vulnerability/exposure split, but I think e.g. nuclear posturing, decentralized nuclear command structures, and launch-on-warning systems constitute a vulnerability, while global-warming-caused conflicts could lead to an exposure of this vulnerability.
(I think this kind of distinction is useful, so we don’t get bogged down in debates or motte/baileys over whether X is an x-risk because of indirect effects, but I’m not 100% behind this particular typology.)
I’m told that CSER is writing something on the indirect risks. My observation is that climate change is a very indirect stressor of the risk of nuclear winter. The causal path would be: extreme climate change ⇒ tension between nuclear powers ⇒ nuclear war ⇒ nuclear winter ⇒ existential catastrophe. Given that the risk of nuclear war conditional on climate change seems considerably lower than the unconditional risk of nuclear war, working on nuclear war directly looks a much better bet, assuming that working on nuclear war directly is in the slightest bit tractable.
We are indeed writing something on this (sorry it is taking so long!). I would dispute your characterization of the principle contributor of climate change to nuclear war though. Working on Barrett and Baum’s recent model of how nuclear war’s might occure I would argue that the greatest threat from climate change is that it creates conditions under which a prec[ititating event such as a regional war might escalate into a nuclear conflict are more likely—i.e. it increases our vulnerability to such threats. This is probably more significant than its direct impact on the number of precipitating events. Since such events are not actually that uncommon (Barret and Baum find over 60 I seem to remember whilst a Chatham House survey found around 20) I think that any increase in our vulnerability to these events would not be insignificant.
What is certainly correct is that the nature of the threat posed by climate change is very different in many ways to that posed by AI. Indeed the pathways from threat to catastrophe for anything other than AI (including pandemics, nuclear weapons, asteroids and so on) are generally complex and circuitous. On the one hand that does make these threats less of a concern because it offers multiple opportunities for mitigation and prevention. However, on the other hand, it makes them harder to study and assess, especially by the generally small research teams of generalists and philosophers who undertake the majority of x-risk research (I am not patronising anyone here, that is my background as well).
What would be the mechanism whereby it increases the risk of nuclear war? The main one I can think of is mass migration, but I’m not sure what the proposed mechanism is. Are there analogues in the past for comparably large mass migrations causing wars or increased nuclear tensions? We’ve had quite large refugee flows recently, but this seems to have had basically no impact on nuclear tensions. Given that the main worry for nuclear winter is US-Russia conflict, how could climate change exacerbate tensions there?
I also think it would be surprising if there had been 60 genuine near misses in the past, but that is another debate. That suggests surprising levels of luck. The Tertrais et al paper questions some claims about nuclear near misses
I think we might disagree about what constitutes a near miss or precipitating event. I certainly think that we should worry about such events even if their probability of leading to a nuclear exchange are pretty low (0.001 lets say) and that it would not be merely a matter of luck to have had 60 such events and no nuclear conflict, it is just that given the damage such a conflict would do they still reprasent an unaceptable threat.
The precise role played by climate change in increasing our vulnerability to such threats depends on the nature of the event. I certainly think that just limiting yourself to a single narrative like migration —> instability —> conflict is far to restrictive.
One of the big issues here is that climate change is percieved as posing an existential threat both to humanity generally (we can argue about the rights and wrongs of that, but the perception is real) and to specific groups and communities (I think that is a less contraversial claim). As such I think it is quite a dangerous element in international relations—especially when it is combined with narratives about individual and national reponsibility, free riding and so on. Of course you are right to point out that climate change is probably not an existential threat to either the USA or Russia but it will be a much bigger problem for India and Pakistan and for client states of global superpowers.
What do you make to the argument that the probability of nuclear winter caused by climate change is considerably lower than the probability of nuclear winter, so focusing more directly on nuclear winter looks a better bet?
Of course it will be smaller, however that does mean that tackelling climate change will not make a sizeable contribution towards reducing the risk of nuclear winter. The question for me is whether nuclear winters that relate to climate change are more or less tractable than nuclear winter as a whole. My view would be that trying to reduce the risk of nuclear winter by tackelling climate change and its consequences may be a more tractable problem then doing so by trying to get nuclear weapons states to disarm or otherwise making nuclear war less likely in general, but that efforts to make nuclear winter more survivable are probably more efficient than either of these policies from a purely x-risk reduction perspective.
However, I also do not think that nuclear winter is the only way in which climate change may lead to an existential threat (at least reading existential threat to include the prospect for an unrecoverable from civilisational collapse) as there are some interesting feedback loops between environmental and social collapse that have the potential to cause non-linear and self-perpetuating shifts in the structure of global civilisation. Admittedly these are hard to study, but from a value maximisation perspective I would say that in the face of uncertainty we will do better if we assume that global civilisation is relatively fragile to such changes than if we assume that it is more robust to them.
I don’t agree that working on climate change is plausibly a better way to reduce the risk of nuclear war than working directly on nuclear war. Firstly, climate change is a very intractable problem in the first place for philanthropists and for national governments, given that action is opposed by entrenched interests across all society and requires cooperation pretty much of all nations. Nuclear peace is opposed by some entrenched interested in the military industrial complex, but these do not reach anywhere near as far into society as a whole. Major results could be achieved just by getting cooperation between Russia and US, which is not true of climate change.
Secondly, climate change is much less neglected than reducing the risk of nuclear war. Thirdly, there have been lots of apparently successful treaties that have e.g. limited the size of US and Russian arsenals. It just seems much easier to make progress on things that foster peace and reduce arsenals than on nuclear war caused by climate change. The path for the latter is extremely indirect.
Given that the risk of nuclear war conditional on climate change seems considerably lower than the unconditional risk of nuclear war
Do you really mean that P(nuclear war | climate change) is less than P(nuclear war)? Or is this supposed to say that the risk of nuclear war and climate change is less than the unconditional probability of nuclear war? Or something else?
Having looked at warhead stocks, nuclear winter research, etc, I think nuclear war isn’t an x-risk either.
I’m also rather doubtful that climate change significantly increases the probability of nuclear war. Regional conflicts and insurgencies in certain places, sure. But the pathway from there to nuclear war is very unclear. You can point to the Indo-Pakistani dyad as a possible flashpoint, but both of them have few nuclear weapons. And their historical conventional conflicts did not escalate to involve other countries.
But it is outcomes that are morally close to extinction, the loss of most of humanity’s capacity and potential. Nuclear winter of a few degrees would not impact agriculture so adversely to cause this to happen. At this point you are multiplying so many small probabilities in series that you cannot call climate change a real x-risk without doing the same for so many other things that are equally likely to set a chain of bad events in motion.
I think it is useful to discuss qualifies as an X-risk. Asteroid/comet impact is widely regarded as an X-risk, but a big one that could cause human extinction might only have a one in a million probability in the next 100 years. This is a 0.0001% reduction in humanity’s long term value. However, if you believe 80,000 Hours that nuclear war might have a ~3% chance in the next 100 years and this could reduce the long term future potential of humanity ~30%, that is a ~1% reduction in the future of humanity this century. So practically speaking, it is much more of an X-risk than asteroids are. Similarly, if you believe 80k that extreme climate change has a ~3% chance in the next 100 years and it reduces the long run potential by ~20%, that is a 0.6% reduction in the long term future of humanity. This again is much larger than asteroids. I personally think the nuclear risk is higher and the climate risk is lower than these numbers. It is true that some of the long-term impact could be classified as trajectory changes rather than traditional X risk. But I think most people are interested in trajectory changes as well.
I don’t think the 80k estimate on climate change is based on a thorough investigation of the science. I just don’t see how from the impacts estimated in the next 100 years, extreme climate change could be thought to be a greater than 0.1% ex risk. The heat stress of >4 degrees would be bad but if things started going that badly, I think the world would take action. In a few decades it will be much cheaper to abate GHGs and everyone will have an interest in doing so
I generally agree. The question is whether we should call something an X-risk by the impact if it happens alone or by the impact*probability. If the latter, and if comets are an X-risk, then we should call extreme climate change (and definitely nuclear war) an X-risk.
By that logic you are turning the idea of an x-risk into anything that really matters in the long run. So poverty is an x-risk too in this definition. That makes it not a useful definition and is also very different from how most people think about the term.
Extinction (or something just as bad): x-risk. I go by that.
“Normal” nuclear war could be only only a first stage of multistage collapse. However, there are some ideas, how to use exiting nuclear stockpiles to cause more damage and trigger a larger global catastrophe—one is most discussed is nuking a supervolcano, but there are others. In Russian sources is a common place that retaliation attack on US may include attack on the Yellowstone, but I don’t know if it is a part of the official doctrine.
Future nuclear war could be using even more destructive weapons (which may exist secretly now). Teller has been working on 10 gigaton bomb. Russians now making Poseidon large torpedo system which will be probably equipped with 100 Mt cobalt bombs.
However, there are some ideas, how to use exiting nuclear stockpiles to cause more damage and trigger a larger global catastrophe—one is most discussed is nuking a supervolcano,
Absurd. Why would anyone do that?
retaliation attack on US may include attack on the Yellowstone, but I don’t know if it is a part of the official doctrine.
Future nuclear war could be using even more destructive weapons
Even the most destructive historical weapons (e.g. Tsar Bomba) have not been deployed. Warheads have gotten smaller over recent decades. No reason for this trend to reverse.
I’ve read that US has an instrument to attack hardened underground facilities by multiple heavy nuclear strike in one place, which allows creating much deeper crate than a single nuclear explosion and destroy targets around 1 km deep. The same way an volcanic caldera cover could be attacked, and such multiple strikes could weaken its strength until it blow up by internal pressure—so you don’t need to go through the whole caldera’s cover. no new weapons for it is needed—just special targeting of already exiting.
I don’t think this is indirect and unlikely at all; in fact, I think we are seeing this effect already. In particular, some of the 2nd-order effects of climate change (such as natural catastrophe-->famine-->war/refugees) are already warping politics in the developed world in ways that will make it more difficult to fight climate change (e.g. strengthening politicians who believe climate change is a myth). As the effects of climate change intensify, so will the dangers to other x-risks.
In particular, a plausible path is climate change immiserates poor/working class + elite attempts to stop climate change hurting working class (eg war on coal) --> even higher inequality --> broad-based resentment against elite initiatives. X-risk reduction is likely to be one of those elite initiatives simply because most X-risks are uninutitive and require time/energy/specialized knowledge to evaluate, which few non-elites have
That’s a good point, but I don’t think my argument was brittle in this sense (perhaps it was poorly phrased). In general, my point is that climate change amplifies the probabilities of each step in many potential chains of catastrophic events. Crucially, these chains have promoted war/political instability in the past and are likely to in the future. That’s not the same as saying that each link in a single untested causal chain is likely to happen, leading to a certain conclusion, which is my understanding of a “brittle argument”
On the other hand, I think it’s fair to say that e.g. “Climate change was for sure the primary cause of the Syrian civil war” is a brittle argument
AFAIK this is not how the current refugee crisis occurred. The wars in the Middle East / Afghanistan were not caused by climate change.
are already warping politics in the developed world in ways that will make it more difficult to fight climate change (e.g. strengthening politicians who believe climate change is a myth
If climate change increases, that will convince people to stop voting for politicians who think it is a myth.
You’re also relying on the assumption that leaders who oppose immigration will also be leaders who doubt climate change. That may be true in the US right now but as a sweeping argument across decades and continents it is unsubstantiated. It’s also unclear if such politicians will increase or decrease x-risks.
“The Syria case, the article finds, does not support ‘threat multiplier’ views of the impacts of climate change; to the contrary, we conclude, policymakers, commentators and scholars alike should exercise far greater caution when drawing such linkages or when securitising climate change.”
I’ll have to investigate more since I was highly confident of such a ‘threat multiplier’ view.
On your other two points, I expect the idea of anthropogenic global warming to continue to be associated with the elite; direct evidence of the climate changing is likely to convince people that climate change is real, but not necessarily that humans caused it. Concern over AGW is currently tied with various beliefs (including openness to immigration) and cultural markers predominantly shared by a subsection of the educated and affluent. I expect increasing inequality to calcify tribal barriers, which would make it very difficult to create widespread support for commonly proposed solutions to AGW.
I really like the writing and material in this post. :) Have you considered the possibility that global warming may introduce instability that could exacerbate other potential conflicts, leading to potential existential crises from nuclear war? Perhaps this is too indirect and unlikely, but my understanding is that EAs that worry about climate change as an x-risk envision this kind of two-step x-risk scenario.
One terminology for this is introduced in “Governing Boring Apocalypses”, a recent x-risk paper. They call direct bad things like nuclear war an “existential harm”, but note that two other key ingredients are necessary for existential risk: existential vulnerability (reasons we are vulnerable to a harm) and existential exposure (ways those vulnerabilities get exposed). I don’t fully understand the vulnerability/exposure split, but I think e.g. nuclear posturing, decentralized nuclear command structures, and launch-on-warning systems constitute a vulnerability, while global-warming-caused conflicts could lead to an exposure of this vulnerability.
(I think this kind of distinction is useful, so we don’t get bogged down in debates or motte/baileys over whether X is an x-risk because of indirect effects, but I’m not 100% behind this particular typology.)
I’m told that CSER is writing something on the indirect risks. My observation is that climate change is a very indirect stressor of the risk of nuclear winter. The causal path would be: extreme climate change ⇒ tension between nuclear powers ⇒ nuclear war ⇒ nuclear winter ⇒ existential catastrophe. Given that the risk of nuclear war conditional on climate change seems considerably lower than the unconditional risk of nuclear war, working on nuclear war directly looks a much better bet, assuming that working on nuclear war directly is in the slightest bit tractable.
We are indeed writing something on this (sorry it is taking so long!). I would dispute your characterization of the principle contributor of climate change to nuclear war though. Working on Barrett and Baum’s recent model of how nuclear war’s might occure I would argue that the greatest threat from climate change is that it creates conditions under which a prec[ititating event such as a regional war might escalate into a nuclear conflict are more likely—i.e. it increases our vulnerability to such threats. This is probably more significant than its direct impact on the number of precipitating events. Since such events are not actually that uncommon (Barret and Baum find over 60 I seem to remember whilst a Chatham House survey found around 20) I think that any increase in our vulnerability to these events would not be insignificant.
What is certainly correct is that the nature of the threat posed by climate change is very different in many ways to that posed by AI. Indeed the pathways from threat to catastrophe for anything other than AI (including pandemics, nuclear weapons, asteroids and so on) are generally complex and circuitous. On the one hand that does make these threats less of a concern because it offers multiple opportunities for mitigation and prevention. However, on the other hand, it makes them harder to study and assess, especially by the generally small research teams of generalists and philosophers who undertake the majority of x-risk research (I am not patronising anyone here, that is my background as well).
What would be the mechanism whereby it increases the risk of nuclear war? The main one I can think of is mass migration, but I’m not sure what the proposed mechanism is. Are there analogues in the past for comparably large mass migrations causing wars or increased nuclear tensions? We’ve had quite large refugee flows recently, but this seems to have had basically no impact on nuclear tensions. Given that the main worry for nuclear winter is US-Russia conflict, how could climate change exacerbate tensions there?
I also think it would be surprising if there had been 60 genuine near misses in the past, but that is another debate. That suggests surprising levels of luck. The Tertrais et al paper questions some claims about nuclear near misses
I think we might disagree about what constitutes a near miss or precipitating event. I certainly think that we should worry about such events even if their probability of leading to a nuclear exchange are pretty low (0.001 lets say) and that it would not be merely a matter of luck to have had 60 such events and no nuclear conflict, it is just that given the damage such a conflict would do they still reprasent an unaceptable threat.
The precise role played by climate change in increasing our vulnerability to such threats depends on the nature of the event. I certainly think that just limiting yourself to a single narrative like migration —> instability —> conflict is far to restrictive.
One of the big issues here is that climate change is percieved as posing an existential threat both to humanity generally (we can argue about the rights and wrongs of that, but the perception is real) and to specific groups and communities (I think that is a less contraversial claim). As such I think it is quite a dangerous element in international relations—especially when it is combined with narratives about individual and national reponsibility, free riding and so on. Of course you are right to point out that climate change is probably not an existential threat to either the USA or Russia but it will be a much bigger problem for India and Pakistan and for client states of global superpowers.
What do you make to the argument that the probability of nuclear winter caused by climate change is considerably lower than the probability of nuclear winter, so focusing more directly on nuclear winter looks a better bet?
Of course it will be smaller, however that does mean that tackelling climate change will not make a sizeable contribution towards reducing the risk of nuclear winter. The question for me is whether nuclear winters that relate to climate change are more or less tractable than nuclear winter as a whole. My view would be that trying to reduce the risk of nuclear winter by tackelling climate change and its consequences may be a more tractable problem then doing so by trying to get nuclear weapons states to disarm or otherwise making nuclear war less likely in general, but that efforts to make nuclear winter more survivable are probably more efficient than either of these policies from a purely x-risk reduction perspective.
However, I also do not think that nuclear winter is the only way in which climate change may lead to an existential threat (at least reading existential threat to include the prospect for an unrecoverable from civilisational collapse) as there are some interesting feedback loops between environmental and social collapse that have the potential to cause non-linear and self-perpetuating shifts in the structure of global civilisation. Admittedly these are hard to study, but from a value maximisation perspective I would say that in the face of uncertainty we will do better if we assume that global civilisation is relatively fragile to such changes than if we assume that it is more robust to them.
I don’t agree that working on climate change is plausibly a better way to reduce the risk of nuclear war than working directly on nuclear war. Firstly, climate change is a very intractable problem in the first place for philanthropists and for national governments, given that action is opposed by entrenched interests across all society and requires cooperation pretty much of all nations. Nuclear peace is opposed by some entrenched interested in the military industrial complex, but these do not reach anywhere near as far into society as a whole. Major results could be achieved just by getting cooperation between Russia and US, which is not true of climate change.
Secondly, climate change is much less neglected than reducing the risk of nuclear war. Thirdly, there have been lots of apparently successful treaties that have e.g. limited the size of US and Russian arsenals. It just seems much easier to make progress on things that foster peace and reduce arsenals than on nuclear war caused by climate change. The path for the latter is extremely indirect.
Do you really mean that P(nuclear war | climate change) is less than P(nuclear war)? Or is this supposed to say that the risk of nuclear war and climate change is less than the unconditional probability of nuclear war? Or something else?
Yes sorry I meant the probability of a nuclear war caused by climate change is lower than the probability of a nuclear war.
Having looked at warhead stocks, nuclear winter research, etc, I think nuclear war isn’t an x-risk either.
I’m also rather doubtful that climate change significantly increases the probability of nuclear war. Regional conflicts and insurgencies in certain places, sure. But the pathway from there to nuclear war is very unclear. You can point to the Indo-Pakistani dyad as a possible flashpoint, but both of them have few nuclear weapons. And their historical conventional conflicts did not escalate to involve other countries.
But remember, X-risk is not just extinction—there are many routes to long term future impacts from nuclear war—some are mentioned here.
But it is outcomes that are morally close to extinction, the loss of most of humanity’s capacity and potential. Nuclear winter of a few degrees would not impact agriculture so adversely to cause this to happen. At this point you are multiplying so many small probabilities in series that you cannot call climate change a real x-risk without doing the same for so many other things that are equally likely to set a chain of bad events in motion.
I think it is useful to discuss qualifies as an X-risk. Asteroid/comet impact is widely regarded as an X-risk, but a big one that could cause human extinction might only have a one in a million probability in the next 100 years. This is a 0.0001% reduction in humanity’s long term value. However, if you believe 80,000 Hours that nuclear war might have a ~3% chance in the next 100 years and this could reduce the long term future potential of humanity ~30%, that is a ~1% reduction in the future of humanity this century. So practically speaking, it is much more of an X-risk than asteroids are. Similarly, if you believe 80k that extreme climate change has a ~3% chance in the next 100 years and it reduces the long run potential by ~20%, that is a 0.6% reduction in the long term future of humanity. This again is much larger than asteroids. I personally think the nuclear risk is higher and the climate risk is lower than these numbers. It is true that some of the long-term impact could be classified as trajectory changes rather than traditional X risk. But I think most people are interested in trajectory changes as well.
I don’t think the 80k estimate on climate change is based on a thorough investigation of the science. I just don’t see how from the impacts estimated in the next 100 years, extreme climate change could be thought to be a greater than 0.1% ex risk. The heat stress of >4 degrees would be bad but if things started going that badly, I think the world would take action. In a few decades it will be much cheaper to abate GHGs and everyone will have an interest in doing so
I generally agree. The question is whether we should call something an X-risk by the impact if it happens alone or by the impact*probability. If the latter, and if comets are an X-risk, then we should call extreme climate change (and definitely nuclear war) an X-risk.
I see, yes good point.
By that logic you are turning the idea of an x-risk into anything that really matters in the long run. So poverty is an x-risk too in this definition. That makes it not a useful definition and is also very different from how most people think about the term.
Extinction (or something just as bad): x-risk. I go by that.
“Normal” nuclear war could be only only a first stage of multistage collapse. However, there are some ideas, how to use exiting nuclear stockpiles to cause more damage and trigger a larger global catastrophe—one is most discussed is nuking a supervolcano, but there are others. In Russian sources is a common place that retaliation attack on US may include attack on the Yellowstone, but I don’t know if it is a part of the official doctrine.
Future nuclear war could be using even more destructive weapons (which may exist secretly now). Teller has been working on 10 gigaton bomb. Russians now making Poseidon large torpedo system which will be probably equipped with 100 Mt cobalt bombs.
Absurd. Why would anyone do that?
I’m sure it isn’t. Also, scientifically speaking it doesn’t even seem possible to ignite a supervolcano with nukes: https://www.iflscience.com/environment/what-would-happen-if-a-nuclear-bomb-was-dropped-on-yellowstone-supervolcano/
Even the most destructive historical weapons (e.g. Tsar Bomba) have not been deployed. Warheads have gotten smaller over recent decades. No reason for this trend to reverse.
Theoretical reasons for Doomsday weapon was laid by Herman Khan in “On Thermonuclear war”. I scanned related chapter here: https://www.scribd.com/document/16563514/Herman-Khan-On-Doomsday-machine
The main idea is that it is ideal defence weapon, as no body will ever attack a country owning such a device.
The idea of attacking the Yellowstone is discussed very often in Russian blogosphere (like here https://izborskiy-club.livejournal.com/310579.html), and interest to the geophysical weapons was strong in the Soviet Union (details here: http://nvo.ng.ru/armament/2006-04-21/6_weapontheyfear.html) - this interest ended up in creating Poseidon artificial tsunami system which is now under testing.
I’ve read that US has an instrument to attack hardened underground facilities by multiple heavy nuclear strike in one place, which allows creating much deeper crate than a single nuclear explosion and destroy targets around 1 km deep. The same way an volcanic caldera cover could be attacked, and such multiple strikes could weaken its strength until it blow up by internal pressure—so you don’t need to go through the whole caldera’s cover. no new weapons for it is needed—just special targeting of already exiting.
Russian Poseidon system has 100-200 Mt bombs delivered by a very large torpedo and is in final stages of construction. https://en.wikipedia.org/wiki/Status-6_Oceanic_Multipurpose_System
I don’t think this is indirect and unlikely at all; in fact, I think we are seeing this effect already. In particular, some of the 2nd-order effects of climate change (such as natural catastrophe-->famine-->war/refugees) are already warping politics in the developed world in ways that will make it more difficult to fight climate change (e.g. strengthening politicians who believe climate change is a myth). As the effects of climate change intensify, so will the dangers to other x-risks.
In particular, a plausible path is climate change immiserates poor/working class + elite attempts to stop climate change hurting working class (eg war on coal) --> even higher inequality --> broad-based resentment against elite initiatives. X-risk reduction is likely to be one of those elite initiatives simply because most X-risks are uninutitive and require time/energy/specialized knowledge to evaluate, which few non-elites have
Beware brittle arguments.
That’s a good point, but I don’t think my argument was brittle in this sense (perhaps it was poorly phrased). In general, my point is that climate change amplifies the probabilities of each step in many potential chains of catastrophic events. Crucially, these chains have promoted war/political instability in the past and are likely to in the future. That’s not the same as saying that each link in a single untested causal chain is likely to happen, leading to a certain conclusion, which is my understanding of a “brittle argument”
On the other hand, I think it’s fair to say that e.g. “Climate change was for sure the primary cause of the Syrian civil war” is a brittle argument
AFAIK this is not how the current refugee crisis occurred. The wars in the Middle East / Afghanistan were not caused by climate change.
If climate change increases, that will convince people to stop voting for politicians who think it is a myth.
You’re also relying on the assumption that leaders who oppose immigration will also be leaders who doubt climate change. That may be true in the US right now but as a sweeping argument across decades and continents it is unsubstantiated. It’s also unclear if such politicians will increase or decrease x-risks.
I’d previously read that there was substantial evidence linking climate change-->extreme weather-->famine--> Syrian civil war (a major source of refugees). One example: https://journals.ametsoc.org/doi/10.1175/WCAS-D-13-00059.1 This paper claims the opposite though: https://www.sciencedirect.com/science/article/pii/S0962629816301822.
“The Syria case, the article finds, does not support ‘threat multiplier’ views of the impacts of climate change; to the contrary, we conclude, policymakers, commentators and scholars alike should exercise far greater caution when drawing such linkages or when securitising climate change.”
I’ll have to investigate more since I was highly confident of such a ‘threat multiplier’ view.
On your other two points, I expect the idea of anthropogenic global warming to continue to be associated with the elite; direct evidence of the climate changing is likely to convince people that climate change is real, but not necessarily that humans caused it. Concern over AGW is currently tied with various beliefs (including openness to immigration) and cultural markers predominantly shared by a subsection of the educated and affluent. I expect increasing inequality to calcify tribal barriers, which would make it very difficult to create widespread support for commonly proposed solutions to AGW.
PS: how do I create hyperlinks?
Highlight your text and then select the hyperlink icon in the pop-up bar.