EPA works with states, communities, and tribes to assure healthy outdoor air quality.  Great progress has been made in achieving national air quality standards, which EPA established in 1971 and which it updates periodically based on the latest science. Climate change complicates efforts to attain and/or maintain safe air quality.

Ground-level ozone and particulate matter are of particular concern. Both pollutants are the result of emissions from diverse sources, travel long distances and across state lines. And both are likely to worsen with the changing climate.

Ground-level ozone

Warming temperatures complicate efforts of many communities to attain and/or maintain the health-based air quality standard.

Particulate matter

Longer and more intense droughts and extreme heat events increase the likelihood of wildfires. As a result, wildfires are expected to increase in many parts of the country. Such fires release significant amounts of particulate matter into the air and threaten public health.