Climate Matters•August 6, 2025
Burning Fossil Fuels Worsens Air Quality
KEY FACTS
Burning fossil fuels creates heat-trapping pollution as well as air pollutants, both of which can worsen air quality and put health at risk.
Air pollutants like PM2.5 and ground-level ozone can cause health issues and premature death — and burning fossil fuels is a key contributor to both pollutants.
Climate change threatens to stall or reverse decades of progress on air quality as it increases the frequency and intensity of weather events, like extreme heat and wildfires, that contribute to poor air quality.
There are climate solutions that also benefit air quality by avoiding harmful air pollutants from burning fossil fuels.
Burning fossil fuels warms the planet and worsens air quality
Air pollution is the leading environmental health threat to people worldwide. According to the World Health Organization, outdoor air pollution causes over 4 million premature deaths each year — primarily due to fine particle pollution exposure. This global disease burden disproportionately affects people living in low- and middle-income countries.
In the U.S., air quality has improved significantly since the Clean Air Act of 1970, which is aimed at reducing emissions of hazardous air pollutants.
Despite major air quality improvements in recent decades, approximately 156 million people in the U.S. currently live in counties with air pollution levels above national health standards.
The continued use of fossil fuels (primarily coal, oil, and methane gas) and their warming effect on our climate are threatening the air quality improvements made in the U.S. Fossil fuel use is responsible for the majority of U.S. greenhouse gas emissions and at least half of all U.S. deaths due to fine particle pollution.
Heat-trapping pollution from burning fossil fuels has caused the planet to warm rapidly — fueling dangerous extreme weather events, like wildfires or extreme heat, that can degrade outdoor air quality.
Burning fossil fuels releases more than heat-trapping pollution; it’s also a major direct source of air pollutants, like fine particulate matter, that worsen air quality and put health at risk.
Harmful air pollution
The Clean Air Act sets standards for six common air pollutants that harm health. Of these, fine particulate matter (PM2.5) and ground-level ozone affect the most people in the U.S. — and burning fossil fuels is a key contributor to both. Levels of both PM2.5 and ground-level ozone have decreased in recent decades, but millions of people across the country still breathe in harmful levels of these pollutants.
Children, elderly people, and pregnant women are more susceptible to air pollution-related diseases and face higher risks from exposure.
Climate Central’s fact sheet, Climate Change & Children's Health: Air Quality, details the ways in which climate change is worsening air pollution and putting children’s health at risk.
Air pollution also has disproportionate impacts among different racial and socioeconomic groups. People with low incomes and people of color are among those who may be at increased risk of premature death from fine particle pollution.
Climate change drives extreme weather that worsens air quality
Climate change is increasing the frequency and intensity of weather events that affect air quality, including extreme heat that forms unhealthy ground-level ozone and wildfires that produce harmful smoke. These are a few of the ways that the warming climate worsens air quality (see Chapter 14 in the Fifth National Climate Assessment).
More extreme heat promotes unhealthy ground-level ozone formation.
Climate change is increasing dangerous extreme heat for billions of people across the globe, creating the hot, sunny conditions necessary for ground-level ozone formation. Additionally, persistently hot weather can trap air pollutants in the lower atmosphere, in a phenomenon known as stagnation. These nearly stationary domes of hot air may hold harmful particulates and unhealthy ground-level ozone.
Exposure to ground-level ozone pollution can cause eye and lung irritation, coughing or shortness of breath, an increased risk of asthma attacks, cardiovascular damage, and increased susceptibility to infections.
Ground-level ozone, an ingredient in smog, is a byproduct of chemical reactions between other pollutants (namely, nitrogen oxides and volatile organic compounds) that take place on hot, sunny days. These so-called precursor pollutants come from sources such as gas-powered vehicles, fossil fuel-burning power plants, and industrial facilities. Depending on the level of exposure, ground-level ozone can cause health issues ranging from mild to severe.
More wildfire leads to more harmful smoke pollution.
Climate change is causing more frequent fire weather — a combination of hot, dry, windy conditions that prime the landscape for wildfires to ignite and spread — and therefore, more wildfire smoke and unhealthy PM2.5 pollution. The increases of wildfire smoke since 2016 have either stalled or reversed decades-long air quality improvements in 30 U.S. states.
Wildfire smoke is a complex mix of pollutants, but fine particle pollution, which accounts for about 90%, is the main threat to human health. When people breathe in wildfire smoke, PM2.5 particles can make their way deep into the lungs and even into the bloodstream, causing a range of health effects from minor irritation to serious cardiovascular and respiratory illness. From 2006 to 2020, climate change contributed to approximately 15,000 wildfire particulate matter deaths in the U.S.
Fine particle pollution, or PM2.5, includes particles with a diameter of 2.5 micrometers or smaller. That’s less than 5% of the width of a human hair. Most particulate matter forms as a result of chemical reactions between air pollutants emitted from burning fossil fuels. Wildfire smoke is largely composed of PM2.5, which can cause a range of health issues when it enters the lungs and bloodstream, including cardiovascular and respiratory illness.
Climate solutions can be air quality solutions
There are climate solutions that can reduce both heat-trapping pollution and air pollutants, thereby slowing warming while also improving air quality. The Fifth National Climate Assessment (see Figure 14.7) identifies emissions-reducing actions can benefit the climate, air quality, and health, including:
Electric vehicles. About 80% of transportation-related emissions come from fueling cars and trucks with gasoline and diesel. Gas-powered vehicles emit unhealthy smog-forming pollutants from their tailpipes. Replacing those with electric vehicles can reduce tailpipe emissions, avoid additional warming, and improve air quality and health.
Wind and solar power. Coal- and gas-fired power plants currently produce one-quarter of U.S. greenhouse gas emissions. Fossil fuel-fired power plants are also the largest source of multiple types of air pollution in the U.S. Renewable energy sources like wind and solar provide an alternative to burning fossil fuels for electricity production.
Electrification in homes and businesses. Swapping fossil-fuel powered appliances (like gas stoves or furnaces) for electric alternatives (like electric stoves or heat pumps) can reduce direct greenhouse gas emissions.
Actions that reduce planet-warming greenhouse gases can directly benefit air quality, but many do not. Biomass, for example, can be an alternative to fossil fuels that produces less carbon pollution, but biomass burning can contribute to air pollution without appropriate controls.
Similarly, not all air quality improvements will reduce or slow warming. For example, the reduction of the global emissions of aerosols is very beneficial to air quality and human health, but it potentially accelerates warming by removing planet-cooling aerosols from the atmosphere.
LOCAL STORY ANGLES
View real-time data about air quality near you.
The U.S. Air Quality Index, AirNow, provides air quality data for your neighborhood, including local ozone and PM2.5 levels. The AirNow Fire & Smoke Map provides local fire and smoke plume detection.
See areas that do not meet national air quality standards.
The EPA collaborates with state, local and tribal agencies to identify areas of the U.S. that do not meet the national ambient air quality standards (NAAQS). These nonattainment areas must develop plans to reduce air pollution to meet the NAAQS. See if locations in your state are nonattainment areas.
Check the air quality at national parks
Hazy air quality can affect visibility at some of our nation’s most scenic locations. Find live ozone and PM2.5 levels for national parks near you with the National Park Service’s Live Weather & Air Quality Data website.
CONTACT EXPERTS
J. Jason West, PhD (he/him)
Professor
Department of Environmental Sciences & Engineering
University of North Carolina
Relevant expertise: climate change and air pollution, co-benefits of air quality improvements and climate solutions
Contact: jasonwest@unc.edu
FIND EXPERTS
Submit a request to SciLine from the American Association for the Advancement of Science or to the Climate Data Concierge from Columbia University. These free services rapidly connect journalists to relevant scientific experts.
Browse maps of climate experts and services at regional NOAA, USDA, and Department of the Interior offices.
Explore databases such as 500 Women Scientists, BIPOC Climate and Energy Justice PhDs, and Diverse Sources to find and amplify diverse expert voices.
Reach out to your State Climate Office or the nearest Land-Grant University to connect with scientists, educators, and extension staff in your local area.