Climate economists have used a concept known as the social cost carbon over the years to calculate the dollar value of each ton of carbon dioxide added to the atmosphere. The White House announced in February that the government will be considering the social cost carbon when drafting new environmental regulations.A researcher has now created a mortality cost for carbon that includes the death toll from climate-related heat loss. Today's Nature Communications paper published a new estimate that to save one person, we would need to stop 4,434 metric tonnes of carbon dioxide being released into our atmosphere. This amount is equivalent to the lifetime carbon dioxide emissions of 3.5 Americans.Graduate student Daniel Bressler at Columbia University in sustainable development and the study's author estimates that global heat-related deaths would be reduced by 74 million if all countries could decarbonize, i.e. eliminate carbon emissions by 2050. Bressler says that there are many lives that can be saved by reducing carbon emissions at all levels: at the individual, company, national, and global level.Bressler's research focuses on climate-driven extreme heat. This can cause heat stroke, dehydration and respiratory and organ problems, particularly among elderly and vulnerable populations. Bressler said that he used an existing model for the social cost carbon, originally developed by William Nordhaus at Yale University. This figure was initially set at $37 per tonne. He then updated the model with new research that describes how climate change affects public health and increases the number of heat-related deaths. The scenario assumed that industrial emissions would continue to rise through 2050, before easing off for the remainder of the century.Bressler said that I compared the Nordhaus model to the updated climate information and that I came to the conclusion that less than 5% of the original damages were caused by mortality. A heat dome that erupted over the Pacific Northwest in June resulted in more than 100 deaths in Washington, Oregon and almost 500 deaths in British Columbia.Bressler's paper changes the social cost of carbon to $37 per ton and past the White Houses current value $51, to $258 per metric tons. This number represents all the social damages that come from releasing each ton carbon, such as lost productivity due to storms and agricultural losses, damages caused sea level rise, and money spent on climate-related flooding.It is common for people to die from heat-related causes each summer, such as lack of air conditioning or preexisting conditions. There is now more evidence to support this calculation. Researchers from the UK's London School of Hygiene and Tropical Medicine published in March a study in Nature Climate Change. It found that climate change was responsible for 37% of all heat-related deaths worldwide. To estimate the mortality consequences of the increased heat exposure caused by human-induced warming between 1991 and 2018, they used data from 43 countries.
