The Yellow School Bus and Kids' Health: A Social Cost-Benefit Analysis

Abstract

Abstract Improving the air quality for schoolchildren riding aboard public school buses in Montgomery County, Maryland, has been the goal of this project from the outset. As the school district mulled whether to transition its all-diesel school bus fleet to electric, this research strove to provide policymakers with the analysis necessary to make informed decisions for the betterment of public air quality and children’s health. Balancing the health needs of an immediate community and the long-lasting consequences of a changing climate is an issue policymakers are expected to face in their efforts to mitigate climate change. This thesis offers a microlevel look at a Maryland school bus fleet in the beginning stages of replacing its all-diesel bus fleet with electric buses. The Alternative Fuel Life Cycle Environmental and Economic Transportation (AFLEET) tool was used to calculate the emissions of the diesel bus fleet and projected change in emissions as the diesel fleet transitions to an electric school bus fleet. Marginal damages were calculated using the Air Pollution Emission Experiments and Policy (APEEP) analysis tool for NOx, SO2, PM2.5, and VOC. Additionally, CO2 marginal damages were calculated using federal and Maryland Social Costs of Carbon. The analysis showed that the do-nothing option, that is, replacing aging diesel buses with new diesel buses, would continue to contribute upwards of USD275,500 in social costs just from a year’s worth of schoolyard bus engine idling; another USD793,000 in social costs can be attributed to the annual driving of the buses. The proposed 10- and 15-year plans of replacing diesel buses with electric was projected to reduce marginal damages significantly. The 10-year plan came with a 38.2% reduction in emissions-based social costs from driving the bus and the 15-year plan came with a 46.3% reduction. In the case of 30 minutes per trip of idling, the phasing out of diesel was similar for both the 10- and 15-year plans, about a 38% reduction. The electric buses, however, revealed significant social costs also, although not ones that directly impact Montgomery County schoolchildren. The results varied widely, depending on whether calculating for a minimal renewable energy scenario or the more progressive one touted by policymakers. In the best-case scenario, and following Maryland renewable energy mandates, social costs for the energy needed to power the electric school bus fleet in the 10-year plan would amount to USD56.6 million; in the worst case, with the state unable to purchase renewable energy credits to meet its mandate, its social cost under the 15-year plan was projected to be USD129.9 million. Results revealed a potential conundrum for policymakers. Electric school buses do, indeed, remove ground-level pollutants from the community, sparing schoolchildren from exposure. But a fossil fuel heavy electric grid increases the social costs exponentially, forcing greenhouse gases and other pollutants into other communities. The consequences for the world-at-large could be much more dire if the county and state don’t move aggressively to transform the fossil fuel-heavy energy grid into one that is generated primarily by renewable energy sources. Simply put, the move to electrify the transportation sector is not sustainable without a clean energy grid.