Integration of Multiple Climate Change Mitigation Actions and Health Co-Benefits: A Framework Using the Global Calculator.

Background: The Global Calculator is an open-source model of the world's energy, land, and food systems. It is a pioneering online calculator to project the impact of interventions to mitigate climate change on global temperature. A few studies have been conducted to evaluate the health co-benefits of climate change mitigation, though they are still fragmentary.

Objectives: Our objectives are to identify which sectors could yield the greatest results in terms of climate change mitigation and suggest whether existing evidence could be used to weight mitigation actions based on their ancillary impacts on human health or health co-benefits.

Methods: Using the International Energy Agency (IEA) 4DS scenario as a referent (i.e., the "4-degree Celsius increase scenario"), we simulated changes in different policy "levers" (encompassing 43 potential technological and behavioral interventions, grouped by 14 sectors) and assessed the relative importance of each lever in terms of changes in annual greenhouse gas emissions in 2050 and cumulative emissions by 2100. In addition, we examined existing estimates for the health co-benefits associated with different interventions, using evidence from the Lancet Pathfinder and four other tools.

Discussion: Our simulations suggest that-after accounting for demographic change-transition from fossil fuels to renewables and changes in agriculture, forestry, land use, and food production are key sectors for climate change mitigation. The role of interventions in other sectors, like carbon capture and storage (CCS) or nuclear power, is more modest. Our work also identifies mitigation actions that are likely to have large health co-benefits, including shifts to renewable energy and changes in land use as well as dietary and travel behaviors. In conclusion, some of the sectors/interventions which have been at the center of policy debate (e.g., CCS or nuclear power) are likely to be far less important than changes in areas such as dietary habits or forestry practices by 2050. https://doi.org/10.1289/EHP14906.