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 (PM2.5) 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. More efficient and targeted climate mitigation policies require an improved understanding of how the associated air quality and health benefits will be distributed. This study assesses, at the country level, the health effects of a global carbon price under different future scenarios.

Automated summary

Climate mitigation efforts can have positive impacts on air quality and health. However, the distribution of these health benefits across countries is uncertain. This study uses a comprehensive model to assess the country-specific health effects of a global carbon price under different future scenarios. The results show consistent reductions in air pollution and associated mortality risks for countries with high levels of pollution, but potential increases in mortality risks for less-polluted countries due to emissions from bioenergy use and land-use changes. Improving the representation of uncertainties, country-specific characteristics, and cross-sector interactions is crucial for better understanding the distributional outcomes of climate mitigation policies.