Learn how air pollution can harm your health and the environment, and what EPA is doing to protect the air we breathe.

Understanding and addressing climate change is critical to EPA’s mission of protecting human health and the environment.

EPA’s indicators use the best available observed data to show how the climate is changing.

Greenhouse gases from human activities are the most significant driver of observed climate change since the mid-20th century.1 

This indicator describes how the levels of major greenhouse gases in the atmosphere have changed over time.

This indicator measures the “radiative forcing” or heating effect caused by greenhouse gases in the atmosphere.

This indicator examines U.S. and global surface temperature patterns over time.

This chapter focuses on observed changes in temperature, precipitation, storms, floods, and droughts.

This indicator describes trends in unusually hot and cold temperatures across the United States.

This indicator describes trends in average precipitation for the United States and the world.

This indicator tracks the frequency of heavy precipitation events in the United States.

This indicator examines changes in the size and frequency of inland river flood events in the United States.

This indicator examines the frequency, intensity, and duration of hurricanes and other tropical storms in the Atlantic Ocean, Caribbean, and Gulf of Mexico.

This indicator measures drought conditions of U.S. lands.

This feature provides a closer look at trends in temperature and drought in the southwestern United States.

Covering about 70 percent of the Earth’s surface, the world’s oceans have a two-way relationship with weather and climate.

This indicator describes trends in the amount of heat stored in the world’s oceans.

This indicator describes how sea level has changed over time. The indicator describes two types of sea level changes: absolute and relative.

This indicator describes changes in the chemistry of the ocean that relate to the amount of carbon dioxide dissolved in the water.

This indicator describes global trends in sea surface temperature.