This is fantastic to finally have a cost-effectiveness model for the long-term future for climate change!
This conclusion would hardly change due to including effects of removing GHG emissions which do not lead to trajectory changes.
I do think that trajectory changes such as making it more likely that worse values end up in AI, perhaps caused by an abrupt climate change catastrophe triggering a cascade, could be a significant multiplier for cost-effectiveness. I don’t think you clarified whether when you say tonnes of carbon whether you actually mean carbon (which academia typically uses), or CO2 (which industry/popular typically uses). I think it makes sense that you do cost-effectiveness, e.g. of CCF as (2 kt/$), because of issues dealing with uncertainty. But I think it’s worth pointing out that this cost-effectiveness is around five orders of magnitude higher than typical climate actions, such as subsidizing renewable energy or electric vehicles (~$100/tC). For the cost-effectiveness bar (bp/G$) estimates, it seems to me that the people were answering a different question than Open Phil, where the former were referring to the bar now, and the latter was referring to the last dollar. I think the last dollar of Open Phil is more appropriate (especially because the last dollar of EA would be significantly lower cost effectiveness than this), and would allow climate change to be about two orders of magnitude less cost-effective and still meet the bar.
In addition, it should be noted there seem to be opportunities whose cost-effectiveness is above the bar of 2 bp/G$. Denkenberger 2021 and Denkerberger 2022 estimate the following 5th and 95th percentiles[14] (in bp/G$):
To be clear, these resilience cost-effectiveness estimates include not just the amelioration of climate catastrophes, but also nuclear and others (and they include trajectory changes).
I don’t think you clarified whether when you say tonnes of carbon whether you actually mean carbon (which academia typically uses), or CO2 (which industry/popular typically uses).
I meant tonnes of GHG, namely CO2e. I have now clarified this in the 1st footnote.
But I think it’s worth pointing out that this cost-effectiveness is around five orders of magnitude higher than typical climate actions, such as subsidizing renewable energy or electric vehicles (~$100/tC).
I agree. The 1st bullet point of the Discussion now addresses this.
I think the last dollar of Open Phil is more appropriate (especially because the last dollar of EA would be significantly lower cost effectiveness than this), and would allow climate change to be about two orders of magnitude less cost-effective and still meet the bar.
I think the cost-effectiveness of the last dollar of OP’s longtermist projects is similar to that of the last dollar of other organisations in the EA space funding longtermist projects, because I believe the money of OP and such organisations is fungible to a reasonable extent. I would say OP’s estimate of 0.05 bp/G$ is lower than the others mostly because it is an underestimate.
I’m asking to get a sense of what the current margin of funding looks like, as a way to help researchers and others prioritize our efforts.
So I don’t think they were answering for last dollar. I believe Open Phil said that it is willing to fund anything that meets its last dollar bar now, but their current bar could be higher now. I guess you could argue that there is uncertainty in what the last dollar bar will be, so we should stay at the current bar for the foreseeable future. However, if something is urgent, that is we could miss out on the X-risk reduction if we don’t do it in the next few years, I think that we should be using the last bar for current decisions. The case of climate change is complicated because the impacts are mostly a century or so in the future, but you could argue that there are opportunities to decarbonize now that will be gone in the future because that carbon will already be emitted. I think the case is clearer for resilience to catastrophes that could happen in the next few years, such as nuclear war, that they are urgent. Another way to think about it is if you would eventually fund these things because they are above the last dollar bar, you get a better benefit to cost ratio by doing it now because you have more overall X-risk reduction (assuming the interventions are long lived).
This is fantastic to finally have a cost-effectiveness model for the long-term future for climate change!
I do think that trajectory changes such as making it more likely that worse values end up in AI, perhaps caused by an abrupt climate change catastrophe triggering a cascade, could be a significant multiplier for cost-effectiveness. I don’t think you clarified whether when you say tonnes of carbon whether you actually mean carbon (which academia typically uses), or CO2 (which industry/popular typically uses). I think it makes sense that you do cost-effectiveness, e.g. of CCF as (2 kt/$), because of issues dealing with uncertainty. But I think it’s worth pointing out that this cost-effectiveness is around five orders of magnitude higher than typical climate actions, such as subsidizing renewable energy or electric vehicles (~$100/tC). For the cost-effectiveness bar (bp/G$) estimates, it seems to me that the people were answering a different question than Open Phil, where the former were referring to the bar now, and the latter was referring to the last dollar. I think the last dollar of Open Phil is more appropriate (especially because the last dollar of EA would be significantly lower cost effectiveness than this), and would allow climate change to be about two orders of magnitude less cost-effective and still meet the bar.
To be clear, these resilience cost-effectiveness estimates include not just the amelioration of climate catastrophes, but also nuclear and others (and they include trajectory changes).
Thanks, David!
I meant tonnes of GHG, namely CO2e. I have now clarified this in the 1st footnote.
I agree. The 1st bullet point of the Discussion now addresses this.
I think the cost-effectiveness of the last dollar of OP’s longtermist projects is similar to that of the last dollar of other organisations in the EA space funding longtermist projects, because I believe the money of OP and such organisations is fungible to a reasonable extent. I would say OP’s estimate of 0.05 bp/G$ is lower than the others mostly because it is an underestimate.
In that EA forum post in a comment, Linch says:
So I don’t think they were answering for last dollar. I believe Open Phil said that it is willing to fund anything that meets its last dollar bar now, but their current bar could be higher now. I guess you could argue that there is uncertainty in what the last dollar bar will be, so we should stay at the current bar for the foreseeable future. However, if something is urgent, that is we could miss out on the X-risk reduction if we don’t do it in the next few years, I think that we should be using the last bar for current decisions. The case of climate change is complicated because the impacts are mostly a century or so in the future, but you could argue that there are opportunities to decarbonize now that will be gone in the future because that carbon will already be emitted. I think the case is clearer for resilience to catastrophes that could happen in the next few years, such as nuclear war, that they are urgent. Another way to think about it is if you would eventually fund these things because they are above the last dollar bar, you get a better benefit to cost ratio by doing it now because you have more overall X-risk reduction (assuming the interventions are long lived).