Interesting, appreciate your reply! I think you raised a couple of concerns:
Bringing an additional child into the world results in them essentially taking from a limited resource (the finite share of carbon emissions that can be captured, mitigated, or tolerated), reducing the resource available for everyone else.
It’s plainly wrong to argue life won’t be substantially worse than today
Have I understood your argument right?
I think (1) is complicated. Even if it’s true that bringing an additional child into the world results in less for everyone else, the primary beneficiary isn’t the parents of the child, but the child themselves (although this depends on whether you take a “total view” or “person-affecting” view of population ethics. It’s true under the total view, which is my own perspective. If you take the person-affecting view, you could disagree). The key point I was trying to make in my post is the benefits accruing to that one child are greater than the total sum of harm that additional child does by existing and producing a carbon footprint. I think other commenters were right to say I haven’t made a strong affirmative case, but at least, I’d appeal to you to consider whether the calculations need to be done.
I’ll attempt a brief calculation, though. I don’t necessarily stand by these figures, but my point is that (from a consequentialist point-of-view) doing a calculation like this is important for understanding whether anti-natalism is a good response to climate change.
The largest impact of climate change on human beings in expectation seems to be forcing people out of their homes and communities to migrate, possibly across thousands of miles to different countries. Many will die of famine, thirst, or other acute problems, but all have their lives uprooted. Understanding the number of people this will impact is difficult, but the best estimate I can find is roughly 200 million. If this scales linearly with the number of people in the world, roughly 8 billion now, then for every 40 new people in the world, we’ll have 1 new climate refugee. Is it worth coming into the world if you have a one in forty chance of being a climate change refugee, or causing someone else to be? Of course no one can actively make that choice, but we can make that choice for someone “in expectation” if we’re in a position to decide whether to bring them into the world. To me a 1 in 40 chance of a bad outcome is worth a 39 out of 40 chance of a good outcome.
But even though that still seems a worthwhile gamble, in reality, I think the situation is much, much less dire than that. The impact of climate change won’t scale linearly, because as we get more people, we’ll spend more resources on carbon capture and transitioning to a zero emission economy. This does impose costs on people, but the sacrifice of driving a bit less, or spending a bit more money on solar panels, or other forms of getting to carbon zero, seem less of a sacrifice than not existing at all. This isn’t completely obvious, because the burden is across the whole of society, but I’ll have to leave that exercise for the future.
For the second point (2): people have done their best to work out the economic impact of climate change. The best indications are in the range of 2-10% of world GDP. On average, the US and other developed economies grow about 1-2% a year, or 10-20% a decade. So the impacts of climate change, and responding to it, will cost us a decade of growth and rise in living standards,. But, overall, it seems like living standards will still be higher in future than they are now, even accounting for the impact of climate change.
Yes, but 2 applies to rampant CC (climate change) and 1 within the CC argument.
If I understand it right, your reply challenges the idea that the net effect of having progeny is exacerbate CC, at least in the long run, which I thought you deliberately intended not to do in the post. I think this is a completely different argument, one that I don’t want to go to because it lacks any end: CC is a continuum, its effects are not linear, tipping points are not well understood, its effects will knock-on other effects, it all depends on technology and infrastructure (effective EROIs from alternatives to fossil fuels are lower than we could wish, it is at least very hard to change the infrastructure of the whole society to accommodate a complete change in energy sources, carbon capture and storage at scale may be possible or may not...), unknown unknowns...
I guess my central point was that you cannot argue that CC should not be a significant factor deciding on having children or not (if you care for total happiness), without arguing whether having children is something that will effectively exacerbate CC in the long run or not. And I think you were trying to do that.
If having children does effectively exacerbate CC in the long run, even if its effects in the happiness of the very next (few?) generation(s) may still be net-positive, in the long run this is overwhelmingly negative (in the far off limit, Earth is like Venus). If having children does not effectively exacerbate CC in the long run, there is no debate. And everything in between (now it does but later not, it does but up to a certain point, it does but actual human population will decrease...) is a hugely messy debate.
BTW, the GDP calculations are useless without knowing its assumptions. And if they come from Nordhaus, his calculations seem to be really, really bad, with utterly unrealistic assumptions. Things like calculating the differences in GDP of regions with, XºC average temperature difference and extrapolating it to CC without accounting, for example, that many regions on Earth will be inhabitable if their average temperature increases XºC. Note that, although he’s got a Nobel price for it, basically no one in fields related to sustainability research (except for some economists, I guess) accept them.
Some great points, and you’ve got me thinking again, honestly. I’ll concede that if the GDP impact or human life impact were quite a bit different, and they absolutely could be, I’d be...at least thinking a lot harder about this.
I guess my central point was that you cannot argue that CC should not be a significant factor deciding on having children or not (if you care for total happiness), without arguing whether having children is something that will effectively exacerbate CC in the long run or not. And I think you were trying to do that.
That a fair criticism. Trying to sum up, I think the point I’m trying to get across (poorly expressed in my OP, I have to say) is that
(1) one should (under a total view of happiness) include the enjoyment one’s potential child will get out of life in the calculations
(2) the enjoyment one’s potential child will get out of life is almost certainly still positive, and
(3) to make a new person’s existence net-negative, the marginal impact of climate change of an extra person would have to be large to outweigh the total utility of an extra person living, say 40-80 well-being adjusted life-years. While we can all see the impact of climate change as a whole is large, that is the combined impact of 8 billion people; the individual impact of each marginal person is much smaller than the WALYs they experience through existing.
On my understanding of impacts, I had thought (2) and (3) would be uncontroversial given the evidence. Thus, I mainly wanted to point out the analytical argument outlined in the previous paragraph, and that would be enough. But now you’ve told me true GDP impact could be much greater than 10%, I’m much less certain about that! I guess you are right at least that the debate is “messy”.
Do you have any sources you can recommend that contain more reliable estimates of (a) GDP impact, (b) human life impact, or (c) long-run exacerbation where things become “overwhelmingly negative”? All of that would concern me, particularly the long-run overwhelmingly-negative scenario.
I understand this is getting into an entirely new argument I didn’t make originally, so appreciate if you don’t want to stray, but at some point, I think the “climate cost” to grow the population by some amount is the lesser of the mitigation of their carbon footprint by other means, or the actual effects of their carbon footprint. That makes the assumption that “we” (whoever the imagined “we” is) will choose the lesser cost option, which is problematic, but on the other hand, I’m not sure how much moral responsibility you can build into the choice to have a child if a less impactful alternative to mitigation exists which society as a whole chooses not to pursue.
Hi. Thinking about it, I probably overstated a bit about Nordhaus’ acceptance. Instead of saying “basically no one in fields related to sustainability research” I think “many do not” is probably more accurate. I’m in my bubble and there may be very different bubbles around. And I guess a bad model is better than no model, as one can improve it instead of starting from scratch.
About what you ask for:
(a) I’m not sure. Steve Keen (@ProfSteveKeen in Twitter) is very vocal about how bad Nordhause’s model is, maybe he’s got something. But (rightly) pointing that something is wrong is much easier than building something better, so I’m not sure if he’s got anything. I know he was working on one (several?) paper(s) with Tim Garrett. But Tim is physicist, so it may be something beyond GDP (Tim has a model showing that CO2 emissions energy demand correlates very well with historically cumulative GDP somehow implying that we are actually not decoupling from resource needs).
In general, the problem is that any meaningful CC will have knock-on effects that are ultimately impossible to predict. One can put numbers on those, but then for each ΔTemp there have to be at least different scenarios (only ΔTemp, plus X damage from more extreme environmental phenomena, plus Y effect of war, plus Z from migrations, combinations, degrees...). And on top of that, there are unknown unknowns (e.g. last summer hat heatwaves that melted infrastructure in some parts of the US [I think], which AFAIK basically no one had predicted).
(b) and (c)… maybe the people in the SCER and in the Global Catastrophic Risk Institute? These folks study knock-on effects that CC could produce. Beard from SCER spoke about it in the FLI podcast and I think Luke Kempt also has worked on related topics. I’m less familiar with the people in GCRI. But in general, these all look at overwhelmingly-negative scenarios (CC triggering a nuclear war and so on), so it sounds like what you want.
Interesting, appreciate your reply! I think you raised a couple of concerns:
Bringing an additional child into the world results in them essentially taking from a limited resource (the finite share of carbon emissions that can be captured, mitigated, or tolerated), reducing the resource available for everyone else.
It’s plainly wrong to argue life won’t be substantially worse than today
Have I understood your argument right?
I think (1) is complicated. Even if it’s true that bringing an additional child into the world results in less for everyone else, the primary beneficiary isn’t the parents of the child, but the child themselves (although this depends on whether you take a “total view” or “person-affecting” view of population ethics. It’s true under the total view, which is my own perspective. If you take the person-affecting view, you could disagree). The key point I was trying to make in my post is the benefits accruing to that one child are greater than the total sum of harm that additional child does by existing and producing a carbon footprint. I think other commenters were right to say I haven’t made a strong affirmative case, but at least, I’d appeal to you to consider whether the calculations need to be done.
I’ll attempt a brief calculation, though. I don’t necessarily stand by these figures, but my point is that (from a consequentialist point-of-view) doing a calculation like this is important for understanding whether anti-natalism is a good response to climate change.
The largest impact of climate change on human beings in expectation seems to be forcing people out of their homes and communities to migrate, possibly across thousands of miles to different countries. Many will die of famine, thirst, or other acute problems, but all have their lives uprooted. Understanding the number of people this will impact is difficult, but the best estimate I can find is roughly 200 million. If this scales linearly with the number of people in the world, roughly 8 billion now, then for every 40 new people in the world, we’ll have 1 new climate refugee. Is it worth coming into the world if you have a one in forty chance of being a climate change refugee, or causing someone else to be? Of course no one can actively make that choice, but we can make that choice for someone “in expectation” if we’re in a position to decide whether to bring them into the world. To me a 1 in 40 chance of a bad outcome is worth a 39 out of 40 chance of a good outcome.
But even though that still seems a worthwhile gamble, in reality, I think the situation is much, much less dire than that. The impact of climate change won’t scale linearly, because as we get more people, we’ll spend more resources on carbon capture and transitioning to a zero emission economy. This does impose costs on people, but the sacrifice of driving a bit less, or spending a bit more money on solar panels, or other forms of getting to carbon zero, seem less of a sacrifice than not existing at all. This isn’t completely obvious, because the burden is across the whole of society, but I’ll have to leave that exercise for the future.
For the second point (2): people have done their best to work out the economic impact of climate change. The best indications are in the range of 2-10% of world GDP. On average, the US and other developed economies grow about 1-2% a year, or 10-20% a decade. So the impacts of climate change, and responding to it, will cost us a decade of growth and rise in living standards,. But, overall, it seems like living standards will still be higher in future than they are now, even accounting for the impact of climate change.
Yes, but 2 applies to rampant CC (climate change) and 1 within the CC argument.
If I understand it right, your reply challenges the idea that the net effect of having progeny is exacerbate CC, at least in the long run, which I thought you deliberately intended not to do in the post. I think this is a completely different argument, one that I don’t want to go to because it lacks any end: CC is a continuum, its effects are not linear, tipping points are not well understood, its effects will knock-on other effects, it all depends on technology and infrastructure (effective EROIs from alternatives to fossil fuels are lower than we could wish, it is at least very hard to change the infrastructure of the whole society to accommodate a complete change in energy sources, carbon capture and storage at scale may be possible or may not...), unknown unknowns...
I guess my central point was that you cannot argue that CC should not be a significant factor deciding on having children or not (if you care for total happiness), without arguing whether having children is something that will effectively exacerbate CC in the long run or not. And I think you were trying to do that.
If having children does effectively exacerbate CC in the long run, even if its effects in the happiness of the very next (few?) generation(s) may still be net-positive, in the long run this is overwhelmingly negative (in the far off limit, Earth is like Venus). If having children does not effectively exacerbate CC in the long run, there is no debate. And everything in between (now it does but later not, it does but up to a certain point, it does but actual human population will decrease...) is a hugely messy debate.
BTW, the GDP calculations are useless without knowing its assumptions. And if they come from Nordhaus, his calculations seem to be really, really bad, with utterly unrealistic assumptions. Things like calculating the differences in GDP of regions with, XºC average temperature difference and extrapolating it to CC without accounting, for example, that many regions on Earth will be inhabitable if their average temperature increases XºC. Note that, although he’s got a Nobel price for it, basically no one in fields related to sustainability research (except for some economists, I guess) accept them.
Some great points, and you’ve got me thinking again, honestly. I’ll concede that if the GDP impact or human life impact were quite a bit different, and they absolutely could be, I’d be...at least thinking a lot harder about this.
That a fair criticism. Trying to sum up, I think the point I’m trying to get across (poorly expressed in my OP, I have to say) is that
(1) one should (under a total view of happiness) include the enjoyment one’s potential child will get out of life in the calculations
(2) the enjoyment one’s potential child will get out of life is almost certainly still positive, and
(3) to make a new person’s existence net-negative, the marginal impact of climate change of an extra person would have to be large to outweigh the total utility of an extra person living, say 40-80 well-being adjusted life-years. While we can all see the impact of climate change as a whole is large, that is the combined impact of 8 billion people; the individual impact of each marginal person is much smaller than the WALYs they experience through existing.
On my understanding of impacts, I had thought (2) and (3) would be uncontroversial given the evidence. Thus, I mainly wanted to point out the analytical argument outlined in the previous paragraph, and that would be enough. But now you’ve told me true GDP impact could be much greater than 10%, I’m much less certain about that! I guess you are right at least that the debate is “messy”.
Do you have any sources you can recommend that contain more reliable estimates of (a) GDP impact, (b) human life impact, or (c) long-run exacerbation where things become “overwhelmingly negative”? All of that would concern me, particularly the long-run overwhelmingly-negative scenario.
I understand this is getting into an entirely new argument I didn’t make originally, so appreciate if you don’t want to stray, but at some point, I think the “climate cost” to grow the population by some amount is the lesser of the mitigation of their carbon footprint by other means, or the actual effects of their carbon footprint. That makes the assumption that “we” (whoever the imagined “we” is) will choose the lesser cost option, which is problematic, but on the other hand, I’m not sure how much moral responsibility you can build into the choice to have a child if a less impactful alternative to mitigation exists which society as a whole chooses not to pursue.
Hi. Thinking about it, I probably overstated a bit about Nordhaus’ acceptance. Instead of saying “basically no one in fields related to sustainability research” I think “many do not” is probably more accurate. I’m in my bubble and there may be very different bubbles around. And I guess a bad model is better than no model, as one can improve it instead of starting from scratch.
About what you ask for:
(a) I’m not sure. Steve Keen (@ProfSteveKeen in Twitter) is very vocal about how bad Nordhause’s model is, maybe he’s got something. But (rightly) pointing that something is wrong is much easier than building something better, so I’m not sure if he’s got anything. I know he was working on one (several?) paper(s) with Tim Garrett. But Tim is physicist, so it may be something beyond GDP (Tim has a model showing that
CO2 emissionsenergy demand correlates very well with historically cumulative GDP somehow implying that we are actually not decoupling from resource needs).In general, the problem is that any meaningful CC will have knock-on effects that are ultimately impossible to predict. One can put numbers on those, but then for each ΔTemp there have to be at least different scenarios (only ΔTemp, plus X damage from more extreme environmental phenomena, plus Y effect of war, plus Z from migrations, combinations, degrees...). And on top of that, there are unknown unknowns (e.g. last summer hat heatwaves that melted infrastructure in some parts of the US [I think], which AFAIK basically no one had predicted).
(b) and (c)… maybe the people in the SCER and in the Global Catastrophic Risk Institute? These folks study knock-on effects that CC could produce. Beard from SCER spoke about it in the FLI podcast and I think Luke Kempt also has worked on related topics. I’m less familiar with the people in GCRI. But in general, these all look at overwhelmingly-negative scenarios (CC triggering a nuclear war and so on), so it sounds like what you want.
I hope this helps.
I haven’t really read it, but the title made me think you may (still) be interested: https://news.harvard.edu/gazette/story/2024/08/revising-the-cost-of-climate-change/