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.
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/