Health, climate benefits of electric school buses | News

For immediate release: May 20, 2024

Boston, MA – Replacing diesel school buses with electric school buses could deliver up to $247,600 in climate and health benefits per individual bus, according to a new study by researchers at Harvard TH Chan School of Public Health. The researchers found that these benefits – including reduced greenhouse gas emissions and lower death rates among adults and asthma among children – and associated savings are strongest in large cities and among the fleet of old buses (2005 and before).

The study was published on May 20, 2024 in The Proceedings of the National Academy of Sciences.

While the health and climate benefits of switching from diesel vehicles to electric vehicles are well established, this is the first study to specifically quantify how electric school buses can improve the health of people and the planet.

“Research on air pollution and climate change should strive to quantify health benefits,” said senior author Kari Nadeau, John Rock professor of climate and population studies and chair of the Department of Environmental Health. “Our findings can inform policymakers that greenhouse gas emissions and air pollution are reduced by implementing solutions such as the use of electric vehicles. Our data provides strong evidence that accelerating the ongoing transition to electric school buses will benefit individual, public and planetary health.”

There are approximately half a million school buses in use in the US and a substantial portion of them are older, highly polluting diesel buses. Switching to electric buses is a difficult decision for local, state and federal officials because they are expensive and the health benefits are not well known.

To quantify how diesel and electric school buses affect the climate, the researchers compared the amounts of carbon dioxide emitted from the tailpipes of diesel school buses and from the electricity generation and battery production of electric school buses. To assess the health impacts of the buses, the researchers compared how their respective emissions contribute to fine particulate air pollution (PM2.5), which is linked to adult mortality and the onset of asthma in children.

The study found that replacing the average diesel school bus in the U.S. fleet with an electric bus in 2017 yielded a total of $84,200 in benefits per individual bus. Each electric school bus emits 181 tons less carbon dioxide than its diesel counterpart, amounting to $40,400 in climate benefits. Meanwhile, each electric school bus was associated with $43,800 in health savings, thanks to less air pollution and lower rates of death and childhood asthma.

The study also found that the health benefits of electric school buses vary depending on the location and age of the diesel bus being replaced. Large urban areas – defined as areas with more than a million residents – derive the most significant health benefits from electrifying school buses, given the greater number of people whose air quality is improved. The researchers calculated that replacing a 2005 diesel school bus with an electric bus in a major city would provide $207,200 in health benefits per bus.

“In a dense urban environment where old diesel buses still make up the majority of school bus fleets, the savings from electrifying these buses outweigh the cost of replacement,” Nadeau said. “Not to mention how the tangible benefits of electric school buses can improve lives – especially for racial minorities and people living in low-income communities that are disproportionately affected by the daily health risks of air pollution.”

Nadeau and her co-authors noted that the study did not answer one important question: how electric school buses affect children’s exposure to cabin air pollution while riding the bus. Additional research on this topic could further inform policy decisions.

Ernani Choma, research associate in the Department of Environmental Health, and Lisa Robinson, senior research scientist and deputy director of the Center for Health Decision Science, were co-authors.

“Adopting Electric School Buses in the United States: Health and Climate Benefits,” Ernani F. Choma, Lisa A. Robinson, Kari C. Nadeau, The Proceedings of the National Academy of Sciences, May 20, 2024, doi: 10.1073/pnas.2320338121

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photo: iStock/stu99

For more information:

Maya Brownstein
[email protected]


Harvard TH Chan School of Public Health brings together dedicated experts from many disciplines to train new generations of global health leaders and produce powerful ideas that improve the lives and health of people around the world. As a community of leading scientists, educators and students, we work together to bring innovative ideas from the laboratory to people’s lives – not only to achieve scientific breakthroughs, but also to change individual behavior, public policy and healthcare practices. Each year, more than 400 Harvard Chan School faculty members teach more than 1,000 full-time students from around the world and train thousands more through online and executive education courses. Founded in 1913 as the Harvard-MIT School of Health Officers, the school is recognized as America’s oldest professional training program in public health.