Note that a lot of expected deaths from those estimates come from exacerbating current neglected tropical diseases like malaria and diarrhea, rather than “direct” climate effects like overheating or droughts.
Note also that 200k-2M puts us in the range of “normal” global health problems like malaria, traffic accidents, etc., rather than making it a uniquely terrifying problem.
3. Assuming a total, welfarist view about animals, to figure out whether climate change is good or bad for animal well-being, you literally need to have some reasonable estimates of *each* of the following questions:
- Whether climate change will increase or decrease the total biomass of animals in the wild.
- Whether climate change will increase or decrease the proportion of “moral beings with valence” per unit of biomass.
- Whether animals in the wild have net positive lives right now.
- How climate change will affect the average valence of animals in the wild.
People who talk about climate change’s impact on wild animal welfare focus on the sharp disequilibria, but I expect it to be relatively small on even a short timescale compared to the (basically unknown) level effects.
5. In addition to the citations above, a) this is my impression from informal discussions with people who I believe know a lot more about this topic than I do, and b) There is the meta-level evidence that EAs who think a lot about cause prioritization usually don’t focus on climate change.
6. For example, most (smart, educated) people I talk to are surprised at the balance of increased NTDs as the predominant cause of deaths from climate change, also I learned recently that temperature increases is proportional to log(ppm) rather than linearly, which is really obvious in retrospect but I didn’t think about, and I’m willing to bet that 80%+ of STEM college grads wouldn’t know.
7. This is a very high-level case. I don’t know your life, etc, and if you have an unusually good opportunity to make impact within climate change or if you have detailed models of how climate change affects the world that’s very different from my own, you should probably act on your own viewpoints.
In general, I feel like the burden of proof needed to make life decisions based primarily on some stranger on the internet is quite high, and I don’t think I have met it.
That said, some random brainstorming:
Care about helping poor people not die from malaria due to climate change → work on making sure poor people don’t die from malaria, period
Care about the long-term future → explore other long-termist stuff like AI Safety, biorisk, moral circle expansion etc.
care about animal welfare → factory farming and look into research on wild animal stuff. (Addendum: I think it’d be surprising but not crazy if climate change work is better for animal welfare than work on reducing factory farming, but in worlds where this is true, your priority in 2019 should probably be to study wild animal welfare rather than to assume the connection).
Less obvious stuff:
Generically care about the environment → Look into indoor and outdoor air pollution. (I’m less confident about this suggestion than the previous 3)
8. There are also likely similar values, like caring about the Global South, animals, and future people. It’s very difficult to communicate to someone that you think their life’s work is not necessarily the best thing to do with limited resources (and most people are less used to this criticism than EAs), and extreme prudence is recommended.
A secondary point is nuance. I think it’s bad from both an epistemic and PR perspective if the message will be distorted from “our best understanding of the situation is that mainline climate change mitigation is unlikely to be the marginal best thing to work on for most EA people with flexible career capital” to something more catchy but much less accurate.
It’s very difficult to communicate to someone that you think their life’s work is misguided
Just emphasizing the value of prudence and nuance, I think that this^ is a bad and possibly false way to formulate things. Being the “marginal best thing to work on for most EA people with flexible career capital” is a high bar to scale, that most people are not aiming towards, and work to prevent climate change still seems like a good thing to do if the counterfactual is to do nothing. I’d only be tempted to call work on climate change “misguided” if the person in question believes that the risks from climate change are significantly bigger than they in fact are, and wouldn’t be working on climate change if they knew better. While this is true for a lot of people, I (perhaps naively) think that people who’ve spent their life fighting climate change know a bit more. And indeed, someone who have spent their life fighting climate change probably has career capital that’s pretty specialized towards that, so it might be correct for them to keep working on it.
I’m still happy to inform people (with extreme prudence, as noted) that other causes might be better, but I think that “X is super important, possibly even more important than Y” is a better way to do this than “work on Y is misguided, so maybe you want to check out X instead”.
Yeah I think that’s fair. I think in practice most people who get convinced to work on eg, biorisk or AI Safety issues instead of climate change often do so for neglectedness or personal fit reasons.
Feel free to suggest a different wording on my point above.
EDIT: I changed “misguided”->”necessarily the best thing to do with limited resources”
I also think we have some different interpretations of the connotations of “misguided.” Like I probably mean it in a weaker sense than you’re taking it as. Eg, I also think selfishness is misguided because closed individualism isn’t philosophically sound, and that my younger self was misguided for not being a longtermist.
I think when considering your estimates for 1. it is important to consider the boundaries given by those sources and to contextualise them.
The WHO is only looking at disease burden but even there they are expecting 250k to 2050 (not even looking to 2100) and they estimate that CC will exacerbate malnutrition by 3% of current values—this seems extremely conservative. They don’t seem to include the range increases for most other insect-transmitted diseases, just malaria, even within the extremely limited subset of causes they consider.
Impactlab’s “big data approach”—they don’t give their assumptions, parameters, or considerations—I think this should largely be discounted as a result. It seems to be based on historic and within-trend correlation data, not accounting for risk of any higher-level causes of mortality such as international conflicts, political destabilisation, famine, ecological collapse, climate migration, infrastructure damage etc. that will have an impact and I am guessing aren’t accounted for in their correlational databank.
Danny Bressler is only looking at extrapolating inter-personal conflicts. It doesn’t include famines, pandemics, increased disease burden, ecosystem collapse, great nation conflicts, etc. etc. etc. that are very likely to be much, much worse than the trends considered in his model. As such his 74 million estimate should be considered an extremely conservative lower bound to the estimated value. He is also showing a significant upwards trend per-year, so the burden should be considered to exacerbate over time.
Overall this seems to cast doubt on 1, 4 and 5. For 2. I have also critiqued John Halstead’s work in a previous post, and the Ozy Brennan post is refuting CC as an extinction risk, not as a global catastrophic risk as you use it. He is saying nothing about the chances of >10% likelihood of >10% population decrease. These combined should cause pause for thought when making statement 7.
I think while it’s some evidence that he considers his analysis still quite conservative, the most important contextualization of Danny Bresler’s analysis, for our very high-level purposes of understanding expert opinion as laymen, is that (iirc) he perceives it to be a new/contrarian position, where most estimates of climate change mortality burden is too low (from his perspective).
I also prefer the framing of things I hyperlink as “links I added that I thought might be helpful for helping to understanding the question further,” rather than “sources,” but I think that was my own fault for trying to write a short post at the possible expense of accuracy.
This doesn’t seem to be the context in which you were dropping the link, seeing as they all have top-level summary numbers that feed into your boundaries and point 1 doesn’t say anything about 2m/year being a lower bound, seeing as you are using it as the upper bound. I would like to see these other estimates of climate mortality as they aren’t referenced or seem to feed into point 1.
On a meta-level I think disconnecting sources with the context with which you are referencing them is very unfriendly to the reader as they have to wade through your links to find what you are saying where, but apparently these aren’t even sources for adding evidence to your claims. So I am further befuddled by your inclusion of incidental contextualising literature when you haven’t included references to substantiate your claims. I also think your edit comes across as quite uncharitable to readers (and self-defeating) if you don’t think you can change people’s minds.
If governments stick to their policies (which they have been notoriously bad at so far) then the reduction would only be 10-30%. I’d expect even a 10% decrease to have massive knock on effects to the nutrition and mortality of the world. I expect that is not included in the impact lab report because it is very hard to have papers that encompass the entire scope of the climate crisis.
Of course there could be a lot of changes to how and where we grow crops to avoid these problems, but making sure that we manage this transition well, so that people in the global south can adopt the appropriate crops for whatever their climate becomes seems like something that could use some detailed analysis. It seems neglected as far as I can tell, there may be simple things we can do to help. It is not mainstream climate change mitigation though, so might fit your bill?
You’d need to think there was a very significant failure of markets to assume that food supplies wouldn’t be adapted quickly enough to minimize this impact. That’s not impossible, but you don’t need central management to get people to adapt—this isn’t a sudden change that we need to prep for, it’s a gradual shift. That’s not to say there aren’t smart things that could significantly help, but there are plenty of people thinking about this, so I don’t see it as neglected of likely to be high-impact.
I’m expecting the richer nations to adapt more easily, So I’m expecting a swing away from food production in the less rich nations as poorer farmers would have a harder time adapting as there farms get less productive (and they have less food to sell). Also farmers with now unproductive land would struggle to buy food on the open market
I’d be happy to be pointed to the people thinking about this and planning on having funding for solving this problem. Who are the people that will be funding the teaching of subsistence rice farmers (of all nationalities) how to farm different crops they are not used to etc? Providing tools and processing equipment for the new crop. Most people interested in climate change I have met are still in the hopeful mitigation phase and if they are thinking about adaptation it is about their own localities.
This might not be a pressing problem now[1], but it could be worth having charities learning in the space about how to do it well (or how to help with migration if land becomes uninhabitable).
The way climate scientists use those terms, I think of safeguarding soil quality and genetically engineering or otherwise modifying new crops for the heat as more of climate change adaption than mainstream mitigation problem.
Tony Allan who I quoted in a different comment also believed that there are a bunch of other ecological problems with the future of our current soil quality. This does seem important?
I don’t know nearly enough about the field to have any opinions on tractability or neglectedness (David Manheim who commented below seems to know more).
That said, I personally would be quite surprised if worldwide crop yields actually ended up decreasing by 10-30%. (Not an informed opinion, just vague intuitions about econ).
That said, I personally would be quite surprised if worldwide crop yields actually ended up decreasing by 10-30%. (Not an informed opinion, just vague intuitions about econ).
I hope they won’t too, if we manage to develop the changes we need to make before we need them. Economics isn’t magic
But I wanted to point out that there will probably be costs associated with stopping deaths associated with food shortages with adaptation. Are they bigger or smaller than mitigation by reducing CO2 output or geoengineering?
This case hasn’t been made either way to my knowledge and could help allocate resources effectively.
I found this report on adaptation, which suggest adaptation with some forethought will be better than waiting for problems to get worse. Talks about things other than crops too. The headlines
Without adaptation, climate change may depress growth in global agriculture yields up to 30 percent by 2050. The 500 million small farms around the world will be most affected.
The number of people who may lack sufficient water, at least one month per year, will soar from 3.6 billion today to more than 5 billion by 2050.
Rising seas and greater storm surges could force hundreds of millions of people in coastal cities from their homes, with a total cost to coastal urban areas of more than $1 trillion each year by 2050.
Climate change could push more than 100 million people within developing countries below the poverty line by 2030. The costs of climate change on people and the economy are clear. The toll on human life is irrefutable. The question is how will the world respond: Will we delay and pay more or plan ahead and prosper?
(Caveat here is that I understand much less climate science than I would like, and there are gaps in my knowledge that someone who recently took a few undergrad classes on climate science can fill).
The equilibrium climate sensitivity (ECS) refers to the equilibrium change in global mean near-surface air temperature that would result from a sustained doubling of the atmospheric equivalent CO2 concentration (ΔT2×).
I think the best way to make sense of that is to think of temperature as proportional to log concentration.
(My actual original source is neither, but from an extended discussion with someone else who’s much more knowledgeable about climate science than I am, but also not a real expert)
I skimmed your linked article and I don’t really understand the discrepancy. I could think of some possible reasons (eg, there’s the trivial sense in which all differentiable functions are locally linear) but I’m not confident in them so I’ll sleep on this and see if maybe someone else could comment on it in the meantime.
In the current regime (i.e. for increases of less than ~4 degrees C), warming is roughly linear with cumulative carbon emissions (which is different from CO2 concentrations). Atmospheric forcing (the net energy flux at the top of the atmosphere due to changes in CO2 concentrations) is roughly logarithmic with CO2 concentrations.
How temperatures will change with cumulative carbon emissions at temperatures exceeding ~4 degrees C above pre-industrial is unknown, but will probably be somewhere between super-linear and logarithmic depending on what sorts of feedback mechanisms we end up seeing. I discuss this briefly in at this point in this talk: https://youtu.be/xsQgDwXmsyg?t=520
Some additional notes/clarification/sources for each of the above points:
1. Experts seem (understandably, but rather frustratingly) leery of giving exact death tolls, but here are some examples:
https://www.who.int/news-room/fact-sheets/detail/climate-change-and-health
http://www.impactlab.org/news-insights/valuing-climate-change-mortality/
https://www.youtube.com/watch?v=yXqnKzZiuaE&feature=youtu.be
Note that a lot of expected deaths from those estimates come from exacerbating current neglected tropical diseases like malaria and diarrhea, rather than “direct” climate effects like overheating or droughts.
Note also that 200k-2M puts us in the range of “normal” global health problems like malaria, traffic accidents, etc., rather than making it a uniquely terrifying problem.
2. See prior EA writings by Ozy Brennan:
https://forum.effectivealtruism.org/posts/eJPjSZKyT4tcSGfFk/climate-change-is-in-general-not-an-existential-risk
and John Halstead:
https://docs.google.com/document/d/1qmHh-cshTCMT8LX0Y5wSQm8FMBhaxhQ8OlOeRLkXIF0/edit#
This article has quotes that seem representative of what experts believe:
https://climatefeedback.org/claimreview/earth-is-not-at-risk-of-becoming-a-hothouse-like-venus-as-stephen-hawking-claimed-bbc/
EDIT 2020/1/15: Niel Bowerman estimates the direct risk as real but less than 1⁄10,000 in the next few centuries:
https://forum.effectivealtruism.org/posts/NLJpMEST6pJhyq99S/notes-could-climate-change-make-earth-uninhabitable-for#2pgNMBikjYTkrGuec
3. Assuming a total, welfarist view about animals, to figure out whether climate change is good or bad for animal well-being, you literally need to have some reasonable estimates of *each* of the following questions:
- Whether climate change will increase or decrease the total biomass of animals in the wild.
- Whether climate change will increase or decrease the proportion of “moral beings with valence” per unit of biomass.
- Whether animals in the wild have net positive lives right now.
- How climate change will affect the average valence of animals in the wild.
People who talk about climate change’s impact on wild animal welfare focus on the sharp disequilibria, but I expect it to be relatively small on even a short timescale compared to the (basically unknown) level effects.
4.
https://forum.effectivealtruism.org/posts/GEM7iJnLeMkTMRAaf/updated-global-development-interventions-are-generally-more
5. In addition to the citations above, a) this is my impression from informal discussions with people who I believe know a lot more about this topic than I do, and b) There is the meta-level evidence that EAs who think a lot about cause prioritization usually don’t focus on climate change.
6. For example, most (smart, educated) people I talk to are surprised at the balance of increased NTDs as the predominant cause of deaths from climate change, also I learned recently that temperature increases is proportional to log(ppm) rather than linearly, which is really obvious in retrospect but I didn’t think about, and I’m willing to bet that 80%+ of STEM college grads wouldn’t know.
7. This is a very high-level case. I don’t know your life, etc, and if you have an unusually good opportunity to make impact within climate change or if you have detailed models of how climate change affects the world that’s very different from my own, you should probably act on your own viewpoints.
In general, I feel like the burden of proof needed to make life decisions based primarily on some stranger on the internet is quite high, and I don’t think I have met it.
That said, some random brainstorming:
Care about helping poor people not die from malaria due to climate change → work on making sure poor people don’t die from malaria, period
Care about the long-term future → explore other long-termist stuff like AI Safety, biorisk, moral circle expansion etc.
care about animal welfare → factory farming and look into research on wild animal stuff. (Addendum: I think it’d be surprising but not crazy if climate change work is better for animal welfare than work on reducing factory farming, but in worlds where this is true, your priority in 2019 should probably be to study wild animal welfare rather than to assume the connection).
Less obvious stuff:
Generically care about the environment → Look into indoor and outdoor air pollution. (I’m less confident about this suggestion than the previous 3)
8. There are also likely similar values, like caring about the Global South, animals, and future people. It’s very difficult to communicate to someone that you think their life’s work is not necessarily the best thing to do with limited resources (and most people are less used to this criticism than EAs), and extreme prudence is recommended.
A secondary point is nuance. I think it’s bad from both an epistemic and PR perspective if the message will be distorted from “our best understanding of the situation is that mainline climate change mitigation is unlikely to be the marginal best thing to work on for most EA people with flexible career capital” to something more catchy but much less accurate.
Just emphasizing the value of prudence and nuance, I think that this^ is a bad and possibly false way to formulate things. Being the “marginal best thing to work on for most EA people with flexible career capital” is a high bar to scale, that most people are not aiming towards, and work to prevent climate change still seems like a good thing to do if the counterfactual is to do nothing. I’d only be tempted to call work on climate change “misguided” if the person in question believes that the risks from climate change are significantly bigger than they in fact are, and wouldn’t be working on climate change if they knew better. While this is true for a lot of people, I (perhaps naively) think that people who’ve spent their life fighting climate change know a bit more. And indeed, someone who have spent their life fighting climate change probably has career capital that’s pretty specialized towards that, so it might be correct for them to keep working on it.
I’m still happy to inform people (with extreme prudence, as noted) that other causes might be better, but I think that “X is super important, possibly even more important than Y” is a better way to do this than “work on Y is misguided, so maybe you want to check out X instead”.
Yeah I think that’s fair. I think in practice most people who get convinced to work on eg, biorisk or AI Safety issues instead of climate change often do so for neglectedness or personal fit reasons.
Feel free to suggest a different wording on my point above.
EDIT: I changed “misguided”->”necessarily the best thing to do with limited resources”
I also think we have some different interpretations of the connotations of “misguided.” Like I probably mean it in a weaker sense than you’re taking it as. Eg, I also think selfishness is misguided because closed individualism isn’t philosophically sound, and that my younger self was misguided for not being a longtermist.
I think when considering your estimates for 1. it is important to consider the boundaries given by those sources and to contextualise them.
The WHO is only looking at disease burden but even there they are expecting 250k to 2050 (not even looking to 2100) and they estimate that CC will exacerbate malnutrition by 3% of current values—this seems extremely conservative. They don’t seem to include the range increases for most other insect-transmitted diseases, just malaria, even within the extremely limited subset of causes they consider.
Impactlab’s “big data approach”—they don’t give their assumptions, parameters, or considerations—I think this should largely be discounted as a result. It seems to be based on historic and within-trend correlation data, not accounting for risk of any higher-level causes of mortality such as international conflicts, political destabilisation, famine, ecological collapse, climate migration, infrastructure damage etc. that will have an impact and I am guessing aren’t accounted for in their correlational databank.
Danny Bressler is only looking at extrapolating inter-personal conflicts. It doesn’t include famines, pandemics, increased disease burden, ecosystem collapse, great nation conflicts, etc. etc. etc. that are very likely to be much, much worse than the trends considered in his model. As such his 74 million estimate should be considered an extremely conservative lower bound to the estimated value. He is also showing a significant upwards trend per-year, so the burden should be considered to exacerbate over time.
Overall this seems to cast doubt on 1, 4 and 5. For 2. I have also critiqued John Halstead’s work in a previous post, and the Ozy Brennan post is refuting CC as an extinction risk, not as a global catastrophic risk as you use it. He is saying nothing about the chances of >10% likelihood of >10% population decrease. These combined should cause pause for thought when making statement 7.
I think while it’s some evidence that he considers his analysis still quite conservative, the most important contextualization of Danny Bresler’s analysis, for our very high-level purposes of understanding expert opinion as laymen, is that (iirc) he perceives it to be a new/contrarian position, where most estimates of climate change mortality burden is too low (from his perspective).
I also prefer the framing of things I hyperlink as “links I added that I thought might be helpful for helping to understanding the question further,” rather than “sources,” but I think that was my own fault for trying to write a short post at the possible expense of accuracy.
This doesn’t seem to be the context in which you were dropping the link, seeing as they all have top-level summary numbers that feed into your boundaries and point 1 doesn’t say anything about 2m/year being a lower bound, seeing as you are using it as the upper bound. I would like to see these other estimates of climate mortality as they aren’t referenced or seem to feed into point 1.
On a meta-level I think disconnecting sources with the context with which you are referencing them is very unfriendly to the reader as they have to wade through your links to find what you are saying where, but apparently these aren’t even sources for adding evidence to your claims. So I am further befuddled by your inclusion of incidental contextualising literature when you haven’t included references to substantiate your claims. I also think your edit comes across as quite uncharitable to readers (and self-defeating) if you don’t think you can change people’s minds.
On 1) not being able to read the full text of the impactlab report, but it seem they just model the link between heat and mortality, but not the impact of heat on crop production causing knock on health problems. E.g. http://dels.nas.edu/resources/static-assets/materials-based-on-reports/booklets/warming_world_final.pdf suggests that each degree of warming would reduce the current crop yields by 5-15%. So for 4 degrees warming (baseline according to https://climateactiontracker.org/global/temperatures/ ), this would be 20-60% of world food supply reduction.
If governments stick to their policies (which they have been notoriously bad at so far) then the reduction would only be 10-30%. I’d expect even a 10% decrease to have massive knock on effects to the nutrition and mortality of the world. I expect that is not included in the impact lab report because it is very hard to have papers that encompass the entire scope of the climate crisis.
Of course there could be a lot of changes to how and where we grow crops to avoid these problems, but making sure that we manage this transition well, so that people in the global south can adopt the appropriate crops for whatever their climate becomes seems like something that could use some detailed analysis. It seems neglected as far as I can tell, there may be simple things we can do to help. It is not mainstream climate change mitigation though, so might fit your bill?
You’d need to think there was a very significant failure of markets to assume that food supplies wouldn’t be adapted quickly enough to minimize this impact. That’s not impossible, but you don’t need central management to get people to adapt—this isn’t a sudden change that we need to prep for, it’s a gradual shift. That’s not to say there aren’t smart things that could significantly help, but there are plenty of people thinking about this, so I don’t see it as neglected of likely to be high-impact.
I’m expecting the richer nations to adapt more easily, So I’m expecting a swing away from food production in the less rich nations as poorer farmers would have a harder time adapting as there farms get less productive (and they have less food to sell). Also farmers with now unproductive land would struggle to buy food on the open market
I’d be happy to be pointed to the people thinking about this and planning on having funding for solving this problem. Who are the people that will be funding the teaching of subsistence rice farmers (of all nationalities) how to farm different crops they are not used to etc? Providing tools and processing equipment for the new crop. Most people interested in climate change I have met are still in the hopeful mitigation phase and if they are thinking about adaptation it is about their own localities.
This might not be a pressing problem now[1], but it could be worth having charities learning in the space about how to do it well (or how to help with migration if land becomes uninhabitable).
[1] https://blogs.ei.columbia.edu/2018/07/25/climate-change-food-agriculture/ suggests that some rice producing regions might have problems soon
The way climate scientists use those terms, I think of safeguarding soil quality and genetically engineering or otherwise modifying new crops for the heat as more of climate change adaption than mainstream mitigation problem.
Tony Allan who I quoted in a different comment also believed that there are a bunch of other ecological problems with the future of our current soil quality. This does seem important?
I don’t know nearly enough about the field to have any opinions on tractability or neglectedness (David Manheim who commented below seems to know more).
That said, I personally would be quite surprised if worldwide crop yields actually ended up decreasing by 10-30%. (Not an informed opinion, just vague intuitions about econ).
I hope they won’t too, if we manage to develop the changes we need to make before we need them. Economics isn’t magic
But I wanted to point out that there will probably be costs associated with stopping deaths associated with food shortages with adaptation. Are they bigger or smaller than mitigation by reducing CO2 output or geoengineering?
This case hasn’t been made either way to my knowledge and could help allocate resources effectively.
I found this report on adaptation, which suggest adaptation with some forethought will be better than waiting for problems to get worse. Talks about things other than crops too. The headlines
Without adaptation, climate change may depress growth in global agriculture yields up to 30 percent by 2050. The 500 million small farms around the world will be most affected.
The number of people who may lack sufficient water, at least one month per year, will soar from 3.6 billion today to more than 5 billion by 2050.
Rising seas and greater storm surges could force hundreds of millions of people in coastal cities from their homes, with a total cost to coastal urban areas of more than $1 trillion each year by 2050.
Climate change could push more than 100 million people within developing countries below the poverty line by 2030. The costs of climate change on people and the economy are clear. The toll on human life is irrefutable. The question is how will the world respond: Will we delay and pay more or plan ahead and prosper?
For #6, what is your source that temperature increases are proportional to log(CO2 ppm)? This paper indicates that it’s a simple proportional relationship, no log: https://iopscience.iop.org/article/10.1088/1748-9326/11/5/055006#erlaa23b8f1
(Caveat here is that I understand much less climate science than I would like, and there are gaps in my knowledge that someone who recently took a few undergrad classes on climate science can fill).
https://www.ipcc-data.org/guidelines/pages/reporting.html says it’s logarithmic.
I think this is widely known in the field, for example see here: https://en.wikipedia.org/wiki/Climate_sensitivity#Equilibrium_climate_sensitivity
I think the best way to make sense of that is to think of temperature as proportional to log concentration.
(My actual original source is neither, but from an extended discussion with someone else who’s much more knowledgeable about climate science than I am, but also not a real expert)
I skimmed your linked article and I don’t really understand the discrepancy. I could think of some possible reasons (eg, there’s the trivial sense in which all differentiable functions are locally linear) but I’m not confident in them so I’ll sleep on this and see if maybe someone else could comment on it in the meantime.
In the current regime (i.e. for increases of less than ~4 degrees C), warming is roughly linear with cumulative carbon emissions (which is different from CO2 concentrations). Atmospheric forcing (the net energy flux at the top of the atmosphere due to changes in CO2 concentrations) is roughly logarithmic with CO2 concentrations.
How temperatures will change with cumulative carbon emissions at temperatures exceeding ~4 degrees C above pre-industrial is unknown, but will probably be somewhere between super-linear and logarithmic depending on what sorts of feedback mechanisms we end up seeing. I discuss this briefly in at this point in this talk: https://youtu.be/xsQgDwXmsyg?t=520