Atmospheric Gases

The earth's atmosphere is composed of a mixture of gases that we call air. The most abundant of these gases, molecular nitrogen and molecular oxygen, are not being greatly affected by human activities and are unlikely to be so in the foreseeable future. However, many of the other gases, like carbon dioxide and ozone, are being affected by human activities. Although there are only trace amounts of these gases in the atmosphere, many of them are extremely important to life on Earth and to biodiversity. This article describes many of the important atmospheric gases, their role in affecting the planet, and the factors affecting their changing concentrations in the atmosphere.