I’m sorry but I don’t follow your argument. I’ll try and explain my own logic and perhaps you can point out the key step where I’m going wrong.
The 2014 WHO paper provides an estimate for the number of climate attributed deaths in 2030 and 2050. Let’s imagine that these estimates were 30 deaths and 50 deaths. The GWWC approach then assumes a linear relationship between CO2 emissions and deaths, producing a straight line passing through these estimates. So 2030 sees 30 deaths, 2031 sees 31 deaths, 2032 sees 32 deaths etc. The GWWC approach then subtracts the 2030 estimate from the 2050 estimate to give the change per year in the climate attributes deaths. In this toy example, that would be a figure of 1 death / year / year.
Now imagine that global emissions drop to zero for a single year in 2030, and that climate response was instantaneous—then we’d expect to see 30 deaths in 2030, 30 deaths in 2031, 31 deaths in 2032, 32 deaths in 2033 etc. So over a 50 year period, we’d see 50 saved lives.
However, the original GWWC spreadsheet simply takes a fraction of the deaths / year / year figure, and declares that the resulting total is the number of deaths averted over all time.
Ah, it looks like I was myself confused by the “deaths/year” in line 20 and onward of the original, which represent an increase per year in the number of additional deaths per year. My apologies. At this point I don’t understand the GWWC article’s reasoning for not multiplying by years an additional time.
My prior was that, since economists argue over the relative value of mitigation (at least beyond low hanging fruit) and present consumption, and present consumption isn’t remotely competitive with global health interventions, a calculation that shows mitigation to be competitive with global health interventions is likely to be wrong. But after looking it over another time, I now think that’s accounted for mostly by:
1. The assumption that climate change increases all causes of death by the same percentage as the causes of death investigated here, which, as the article notes, seems very pessimistic. If 57 million people worldwide died in 2016 (and population is increasing but death rate is decreasing), then 5 million additional deaths per year in 2030-2050 seems implausibly large: almost one in ten deaths would be due to climate change.
2. Cool Earth being estimated here to be orders of magnitude more efficient than the kinds of mitigation that economists usually study. (I have no opinion on whether this is accurate.)
since economists argue over the relative value of mitigation (at least beyond low hanging fruit) and present consumption
Do you have any particular sources in mind for this? My understanding is that economists are in strong agreement that action now is much cheaper than action in future.
Re: 1. I think it’s useful to consider concrete examples from history which have killed a large number of people. As per my writeup, in the 20th century, the largest famines killed 10-20M people/decade, so 1-2M people/year, all of which happened when the world had fewer than 4 billion people [source]. So if you think that 1-2M people is implausible, then you’re saying that climate change isn’t likely to cause the same kind of agricultural issues as we’ve previously faced, without serious climate issues.
I was thinking e.g. of Nordhaus’s result that a modest amount of mitigation is optimal. He’s often criticized for his assumptions about discount rate and extreme scenarios, but neither of those is causing the difference in estimates here.
According to your link, recent famines have killed about 1M per decade, so for climate change to kill 1-5M per year through famine, it would have to increase the problem by a factor of 10-50 despite advancing technology and increasing wealth. That seems clearly wrong as a central estimate. The spreadsheet based on the WHO report says 85k-95k additional deaths due to undernutrition, though as you mention, there are limitations to this estimate. (And I guess famine deaths are just a small subset of undernutrition deaths?) Halstead also discusses this issue under “crops”.
I’m sorry but I don’t follow your argument. I’ll try and explain my own logic and perhaps you can point out the key step where I’m going wrong.
The 2014 WHO paper provides an estimate for the number of climate attributed deaths in 2030 and 2050. Let’s imagine that these estimates were 30 deaths and 50 deaths. The GWWC approach then assumes a linear relationship between CO2 emissions and deaths, producing a straight line passing through these estimates. So 2030 sees 30 deaths, 2031 sees 31 deaths, 2032 sees 32 deaths etc. The GWWC approach then subtracts the 2030 estimate from the 2050 estimate to give the change per year in the climate attributes deaths. In this toy example, that would be a figure of 1 death / year / year.
Now imagine that global emissions drop to zero for a single year in 2030, and that climate response was instantaneous—then we’d expect to see 30 deaths in 2030, 30 deaths in 2031, 31 deaths in 2032, 32 deaths in 2033 etc. So over a 50 year period, we’d see 50 saved lives.
However, the original GWWC spreadsheet simply takes a fraction of the deaths / year / year figure, and declares that the resulting total is the number of deaths averted over all time.
Ah, it looks like I was myself confused by the “deaths/year” in line 20 and onward of the original, which represent an increase per year in the number of additional deaths per year. My apologies. At this point I don’t understand the GWWC article’s reasoning for not multiplying by years an additional time.
My prior was that, since economists argue over the relative value of mitigation (at least beyond low hanging fruit) and present consumption, and present consumption isn’t remotely competitive with global health interventions, a calculation that shows mitigation to be competitive with global health interventions is likely to be wrong. But after looking it over another time, I now think that’s accounted for mostly by:
1. The assumption that climate change increases all causes of death by the same percentage as the causes of death investigated here, which, as the article notes, seems very pessimistic. If 57 million people worldwide died in 2016 (and population is increasing but death rate is decreasing), then 5 million additional deaths per year in 2030-2050 seems implausibly large: almost one in ten deaths would be due to climate change.
2. Cool Earth being estimated here to be orders of magnitude more efficient than the kinds of mitigation that economists usually study. (I have no opinion on whether this is accurate.)
Do you have any particular sources in mind for this? My understanding is that economists are in strong agreement that action now is much cheaper than action in future.
Re: 1. I think it’s useful to consider concrete examples from history which have killed a large number of people. As per my writeup, in the 20th century, the largest famines killed 10-20M people/decade, so 1-2M people/year, all of which happened when the world had fewer than 4 billion people [source]. So if you think that 1-2M people is implausible, then you’re saying that climate change isn’t likely to cause the same kind of agricultural issues as we’ve previously faced, without serious climate issues.
I was thinking e.g. of Nordhaus’s result that a modest amount of mitigation is optimal. He’s often criticized for his assumptions about discount rate and extreme scenarios, but neither of those is causing the difference in estimates here.
According to your link, recent famines have killed about 1M per decade, so for climate change to kill 1-5M per year through famine, it would have to increase the problem by a factor of 10-50 despite advancing technology and increasing wealth. That seems clearly wrong as a central estimate. The spreadsheet based on the WHO report says 85k-95k additional deaths due to undernutrition, though as you mention, there are limitations to this estimate. (And I guess famine deaths are just a small subset of undernutrition deaths?) Halstead also discusses this issue under “crops”.