Climate-driven temperature shifts will kill more people in 2100 that infectious diseases do today, making health and safety impacts an important factor in calculating the social cost of carbon, says University of Chicago economist Michael Greenstone, co-director of the university’s Climate Impact Lab.
Testifying before the U.S. Congress in December, Greenstone said his lab’s search for “an updated, data-driven social cost of carbon” calculation had led it to analyse a full suite of data from 40 countries, seeking “to project changes in mortality, energy use, agricultural yields, labour productivity, and coastal vulnerability due to an additional ton of CO2; and then monetize those costs to society,” Forbes reports.
The lab calculated the “full mortality risk” due to climate change at an additional 85 deaths per 100,000 in 2100, compared to 75 per 100,000 from infectious disease in 2018.
While temperature-driven mortality comprises “only a fraction of the total social cost of carbon,” he said that fraction alone will cost society US$23.60 per metric ton of carbon emitted—a figure wildly at odds with the Trump administration’s current estimate of the total social cost of carbon at $1 to $7 per ton.
The Trump calculation—which gutted Obama-era social cost of carbon values ranging from $40 to $51 per ton—is “based on two faulty sets of assumptions,” Greenstone explained. It uses higher discount rates “which are likely inconsistent with the expected nature of real-life payoffs on climate mitigation,” and “fails to account for damages incurred outside the U.S., and therefore discourages other countries from making CO2 reductions that benefit United States citizens.”
Greenstone said his lab’s final estimate for the social cost of carbon will likely be higher than the Obama-era high-water mark, a finding that could help influence recommendations for a meaningful price on carbon.