Effects of global climate mitigation on regional air quality and health

Climate mitigation can bring air quality and health co-benefits. How these health impacts might be distributed across countries remains unclear. Here we use a coupled climate–energy–health model to assess the country-varying health effects of a global carbon price across nearly 30,000 future states of the world (SOWs). As a carbon price lowers fossil fuel use, our analysis suggests consistent reductions in ambient fine particulate matter (PM_2.5) levels and associated mortality risks in countries that currently suffer most from air pollution. For a few less-polluted countries, however, a carbon price can increase the mortality risks under some of the considered SOWs due to emissions increases from bioenergy use and land-use changes. These potential health co-harms are largely driven in our model by the scale and method of deforestation. A robust and quantitative understanding of these distributional outcomes requires improved representations of relevant deep uncertainties, country-specific characteristics and cross-sector interactions.