Association for Public Policy Analysis & Management

California’s set of climate policies is hailed as one of the most important sub-national steps to limit the effects of climate change. These climate programs, which include the cap-and-trade program and the low-carbon fuel standard, are also seen as a critical mechanism to reduce local air pollution in California. Mitigating climate change and reducing local air pollution are generally seen as mutually reinforcing at the aggregate level, but this is not necessarily the case at the local level. Debate surrounding the extension and expansion of California’s climate policies (e.g. AB 398) has drawn attention to the environmental justice argument that flexible market-based mechanisms do not guarantee reduced local air pollution emissions in “hotspots” and may disproportionately affect low-income and minority communities. In other words, while flexible policies like cap-and-trade may cost-effectively achieve carbon emission reductions, they may not cost-effectively address air quality issues in all local communities.

Recent studies of California’s cap-and-trade program have begun to address the intersection of climate policy and local air quality. These studies have focused on carbon and local air pollutant emission trends across communities in California but have not explored the tangible air quality and health implications for specific communities. This research studies the distribution of air pollution co-benefits (or co-harms) resulting from shifts in local pollutant emissions induced by California’s climate change policies. We model the emissions behavior of more than 500 facilities regulated under Mandatory Greenhouse Gas Reporting Regulation, which account for approximately 80% of carbon emissions across the state. We develop bounded emission scenarios through 2030 to estimate the prospective criteria air pollutant emissions from these facilities under different policy regimes. By coupling this emissions data with a reduced-complexity air pollution model, InMap, we assess how changes in criteria air pollutant emissions impact premature mortality due to chronic exposure to PM_2.5 concentrations in disadvantaged communities.

Because local air pollutants, PM_2.5 in particular, impact individuals disproportionately (e.g. due to differential exposure or preexisting conditions), emergency room visit records from Healthcare Cost and Utilization Project State Emergency Department Databases (SEDD) are used to assess individual-level air pollution-related health damages. Such a granular dataset allows us to disaggregate impacts for low-income and minority groups. This research will provide a comprehensive evaluation of the local health effects of California’s climate policies on air pollution exposure across subpopulations and can inform the design of evidence-based policies to simultaneously address global climate change and local air quality.