Residual emissions may perpetuate community-scale inequalities in US air pollution

Abstract

Achieving net-zero targets reduces greenhouse gas emissions and their co-pollutants, thereby improving air quality; however, the magnitude and distribution of these improvements depend on the amount and location of residual emissions offset by carbon dioxide removal (CDR). Here we integrate a series of models and datasets to analyse community-scale particulate matter (PM2.5) impacts of different net-zero scenarios across the contiguous USA. These scenarios avoid many PM2.5-related deaths compared with a reference case, decreasing from around 200,000 to 160,000 and 130,000 deaths in 2050 in the high- and low-CDR scenarios, respectively. However, the low-CDR pathway leads to lower residual emissions and brings greater health improvements that disproportionately benefit non-white and low-income groups. Our results thus suggest that, in the absence of deliberate transition planning, large-scale CDR deployment could be at odds with the equitable distribution of climate mitigation-related health benefits in the USA. The scale of carbon dioxide removal (CDR) could determine the extent of co-emitted air pollutants in net-zero scenarios and potential health impacts. By linking a series of models and datasets, researchers find that low-CDR pathways lead to a more equitable distribution of health benefits across the USA.