About Research in Atmospheric Chemistry

Although they are invisible to the human eye, chemical compounds in the atmosphere influence life on Earth. Even slight variations in the concentrations of water vapor or carbon dioxide, methane, ozone, and other greenhouse gases—not to mention variations in the two main atmospheric components, oxygen and nitrogen—can have dramatic repercussions.

NCAR scientists in the Atmospheric Chemistry Division of the Earth & Sun Systems Laboratory are focusing on understanding how these compounds influence, among other things, past, present and future climate, and regional and global air quality.

Highlighted Topics

• The Chemistry of our Atmosphere

  Understanding the composition of the atmosphere, the processes that modify and control atmospheric composition, and how they may change in time both from natural causes and due to human activity is an important part of understanding our Earth.

• What is air pollution?

  The air we breathe contains many impurities, ranging from smoke that comes from open fires to invisible gases emitted by the tailpipes of cars. These and other pollutants affect human health, damage fragile ecosystems, reduce visibility, and even damage property. They also have profound impacts on climate.

• Pollution around the world

  If pollution stayed in one place, scientists could easily determine where it formed. But, along with the rest of the atmosphere, pollution moves around the globe. This creates a challenge for politicians and others who are trying to control the sources of pollution.

• How does pollution get out of the atmosphere?

  Some types of pollutants break down in sunlight or react with other molecules, dropping out of the air only a few days after they enter it. Others remain in the atmosphere for years or even centuries. While longer-lived pollutants affect the entire globe, those with shorter lives have time only to cause regional impacts before cycling out of the atmosphere.

• Air chemistry and climate

  Scientists know that pollutants have profound impacts on climate. Teasing out all of their effects is difficult because some pollutants, such as sulfate particles, have both warming and cooling effects, and we still lack

• Ozone in the atmosphere

  Pollution is creating two types of problems with ozone, one in the lower atmosphere (troposphere) and the other high in the stratosphere. Ozone depletion in the stratosphere could expose us to unhealthy levels of ultraviolet radiation. At ground level, increasing ozone is a major contributor to health-damaging smog.