November 14, 2023

Better air quality and health are achievable through actions to address climate change, according to the Fifth National Climate Assessment (NCA5), released today by the United States Global Change Research Program.

Published periodically as part of a congressional mandate, the assessment is a summary of the latest climate science, informed by experts in health, energy, environmental sciences and more. It’s also an evaluation of how climate change is affecting the U.S. economy and its populations.

Dr. Jason West

Dr. Jason West

Air quality is an important part of that assessment, says Jason West, PhD, professor of environmental sciences and engineering at the UNC Gillings School of Global Public Health, who is lead author on the NCA5 chapter on air quality.

Because the major sources of greenhouse gases are also major sources of air pollution, the NCA5 report’s chapter on air quality highlights the opportunity to coordinate actions that address both climate change and air quality simultaneously.

Strategies identified in the chapter include policies that reduce use of fossil fuels and replace them with renewable energy, reduce short-lived climate pollutants like methane, and improve energy efficiency across the economy. This includes actions like increasing use of solar electricity, electric vehicles and energy-efficient appliances. The benefits for air quality and public health that these strategies provide would outweigh the cost of implementation, according to the report.

“It really is a two-for-one,” says West. “Taking action on climate change can get us a long way toward cleaner air. The smart approach would be to factor both slowing climate change and cleaning our air in our decisions. Reducing fossil fuel use is at the top of the list.”

Data in the new report also show that climate change will increase air pollution in many parts of the U.S., affecting fine particle and ozone air pollution. These increases in air pollution can worsen health conditions and even lead to premature death. They will also make it harder to reach air quality goals.

The health harms from air pollutants are not evenly distributed. The chapter finds that people of color and those with low socioeconomic status are currently exposed to higher levels of pollution in both urban and rural areas. Major sources of pollution – traffic exhaust, industrial facilities, oil and gas infrastructure, agricultural burns, and animal feeding operations – are often found in communities of color and low-income areas, and systemic racism in historical practices and policies have contributed to these ongoing inequities.

“Climate change will worsen air pollution in many U.S. regions, with impacts on health,” West explains, “especially for vulnerable populations that are already exposed to poor air quality.”

The chapter calls attention, in particular, to the threat of wildfire smoke that has been increasing in frequency and severity due to climate change, particularly in the western U.S. Wildfire smoke is a major source of harmful particulate matter (called PM2.5) and gases that can increase the risk of death, asthma, other respiratory problems and other health impacts. “Recently, we’ve seen cases where smoke from wildfires in the West is blown across the country, affecting huge populations,” explains West.

Changes in climate also affect the levels of pollen and mold that can cause allergic reactions and disease, and the report finds that multiple regions in the U.S. are experiencing longer and more intense pollen seasons. Exposure to high levels of pollen and air pollution can exacerbate respiratory diseases and increase susceptibility to viral infections.

“This report gathers input from scientific experts and the public, and it presents the data in a way that is accessible to general audiences while still remaining true to the science,” West says. “We hope it will be useful in helping decision-makers in every sector create a game plan that can address climate change while improving air quality and health.”

View the full report online.

Contact the UNC Gillings School of Global Public Health communications team at

Visit our communications and marketing team page.
Contact with any media inquiries or general questions.

Communications and Marketing Office
125 Rosenau Hall
CB #7400
135 Dauer Drive
Chapel Hill, NC 27599-7400