Air Pollution

What to know

Climate change is increasing ground-level ozone and particulate matter air pollution in some locations. This leads to many negative impacts on human health.

A young girl in a white T-shirt using an inhaler outside.

Health impact


Climate change is projected to harm human health by increasing ground-level ozone and/or particulate matter air pollution in some locations. Ground-level ozone (a key component of smog) is associated with many health problems:

  • Decreased lung function
  • Increased hospital visits
  • Increased emergency room visits for asthma
  • Increases in premature deaths

Ozone formation

Factors that affect ozone formation include heat, concentrations of precursor chemicals, and methane emissions. Wildfires, air stagnation, and other factors affect particulate matter concentrations.

Climate change intensifies these factors, projecting higher ozone and particulate matter concentrations in specific regions.

Increases in global temperatures could cause associated increases in premature deaths related to worsened ozone and particle pollution.

Health outcome predictions

By 2050, researchers predict that there could be an increase of 1,000 to 4,300 premature deaths annually in the United States due to the combined effects of ozone and particle pollution. This is assuming no changes in regulations or population characteristics. The impact of climate change on airborne particles is less certain compared to ozone.

The current health costs of ozone pollution, which surpass national standards, have resulted in an estimated $6.5 billion nationwide in 2008. These estimates are based on a U.S. assessment of health impacts from ozone levels between 2000 and 2002.

Watch a short video about air quality changes, and learn what communities can do to prepare.


Air Quality – information and resources on air pollutants, particle pollution, and other relevant topics.

Asthma – guidance on asthma symptoms, triggers, and management.

Air Quality and Asthma Data – Data Explorer – interactive maps, tables, and charts.

Climate Change Decreases the Quality of the Air We Breathe