As you noted with McKinsey’s GHG abatement curve, there are many interventions that have a negative abatement cost (though some many nitpick and say we need to account for the opportunity cost for the time it takes to change a lightbulb). Marginal mitigation at present is something we can influence, with the best interventions being <$1/ton.
$30/ton seems like the right order of magnitude if we integrate over all abatement costs to get to net zero emissions. Emission reductions are cheap now but will become much more expensive later; that suggests we may want to use the average abatement cost in our calculations assuming we are committed to solving the problem in its entirety. That leaves a high cost per life saved.
I think there is much more we can do on the abatement side. I remember the discussion when the WHO report came out and also read the recent DICE report. These reports assume deaths with no adaptation. Adaptation is something we can influence. Most of the deaths in the WHO report come from issues of poverty: undernutrition, malaria, dengue, diarrhoeal disease. Heat is also listed, but since the mortality rate from cold temperatures is much greater than from hot temperatures, 1-3C of warming may reduce overall temperature-related deaths (https://robjhyndman.com/hyndsight/seasonal-mortality-rates/). Eradicating malaria in the next several decades removes ~1/4 of the mortality risk in the WHO report. Eradicating extreme poverty gets rid of almost all the mortality risk through better nutrition, medical services, and cooling equipment. These are things we can address and are cheaper than mitigation on a per-life-saved basis. This strongly suggests that if your primary concern is human impacts of climate change, it’s best to spend your money now on global health and anti-poverty development.
As you noted with McKinsey’s GHG abatement curve, there are many interventions that have a negative abatement cost (though some many nitpick and say we need to account for the opportunity cost for the time it takes to change a lightbulb). Marginal mitigation at present is something we can influence, with the best interventions being <$1/ton.
$30/ton seems like the right order of magnitude if we integrate over all abatement costs to get to net zero emissions. Emission reductions are cheap now but will become much more expensive later; that suggests we may want to use the average abatement cost in our calculations assuming we are committed to solving the problem in its entirety. That leaves a high cost per life saved.
I think there is much more we can do on the abatement side. I remember the discussion when the WHO report came out and also read the recent DICE report. These reports assume deaths with no adaptation. Adaptation is something we can influence. Most of the deaths in the WHO report come from issues of poverty: undernutrition, malaria, dengue, diarrhoeal disease. Heat is also listed, but since the mortality rate from cold temperatures is much greater than from hot temperatures, 1-3C of warming may reduce overall temperature-related deaths (https://robjhyndman.com/hyndsight/seasonal-mortality-rates/). Eradicating malaria in the next several decades removes ~1/4 of the mortality risk in the WHO report. Eradicating extreme poverty gets rid of almost all the mortality risk through better nutrition, medical services, and cooling equipment. These are things we can address and are cheaper than mitigation on a per-life-saved basis. This strongly suggests that if your primary concern is human impacts of climate change, it’s best to spend your money now on global health and anti-poverty development.