Good air quality is critical for maintaining life on Earth. But what is air quality and why does it change?

Air is a mixture of naturally occurring gases and human-made air pollutants. Learn more about these gases and the role they play in our atmosphere.

Learn about the six main types of human-made air pollutants and their sources.

Air pollution affects all things. It is harmful to our health, and it impacts the environment. Greenhouse gas pollution affects the entire planet.

While air pollution is a serious problem, it is a problem that we can solve! Lean about actions people can take to reduce emissions and improve air quality.

Air pollutants have an impact on our planet's climate. Some pollutants cause the climate to warm, while others cause a temporary cooling effect.

How is air pollution affected by weather? Some types of pollution are worse in the summer heat, while others are worse in cold winter weather.