Above and Beyond

UCLA’S SUSTAINABLE LA GRAND CHALLENGE aims to lead Los Angeles County into a future in which it obtains all of its energy from renewable resources by 2050 — a transition viewed as essential to the effort to slow the effects of climate change. And if any more incentive to fulfill the ambitious target is needed, a Fielding School-led study underway as part of the Grand Challenge will lay out the significant public health gains that are expected to result from replacing conventional fossil fuels with renewable energy.

Yifang Zhu (PhD ’03), FSPH professor of environmental health sciences and the study’s principal investigator, explains that the shift toward complete reliance on renewable energy — the county was at 22 percent renewable energy usage as of 2015 — is likely to bring an important co-benefit: improved regional air quality. “The sources contributing to the greenhouse gases that drive climate change are the same sources that are contributing to air pollution,” explains Zhu, who also serves as the Fielding School’s associate dean for academic programs. “Additionally, hotter temperatures create conditions that enhance ozone formation, an important pollutant for L.A. smog. For both of these reasons, we expect to find that the process of reducing carbon dioxide emissions in the transition to renewable energy will result in cleaner air.”

At the population level, cleaner air means better health. A substantial body of research has documented the public health impact of air pollution — it is linked to increased risk of respiratory and cardiovascular diseases, neurological problems, certain cancers, and adverse pregnancy outcomes, and contributes to an estimated 8.9 million premature deaths worldwide each year, Zhu notes. Although air quality in Los Angeles has significantly improved over the last several decades thanks to environmental strategies to reduce harmful emissions, Zhu points out that much of L.A. County remains out of compliance with the National Ambient Air Quality Standards for fine particles and ozone, which are associated with the adverse public health impacts.

For their Grand Challenge study, Zhu and her colleagues — including Michael Jerrett, professor and chair of FSPH’s Department of Environmental Health Sciences, as well as researchers from UCLA’s Department of Atmospheric and Oceanic Sciences and the Jet Propulsion Laboratory — will L.A. County’s move toward renewable energy, critical to slowing climate change, would bring an added benefit — cleaner air. FSPH researchers are calculating the potential public health gains. employ state-of-the-art atmospheric chemistry models to estimate future emission trends under different renewable energy scenarios. They will then calculate how those emission reductions would translate into improved regional air quality, and the public health benefits that would result from such improvements.

“Our study will show the extent to which going to renewable energy can not only reduce the impact of climate change, but also have positive health effects by improving air quality,” Zhu says. “The methods we are developing and the knowledge we gain can also help us to address these same questions in other parts of the world that have significant emissions and air pollution concerns, such as China.”

“Conventional cost-benefit policy analyses value future benefits at a discounted rate,” Jerrett notes. “But if our study demonstrates that efforts to mitigate climate change will also save lives in the short term, the policy incentive becomes more compelling.”