Greenhouse gases are water vapor, carbon dioxide, tropospheric ozone, nitrous oxide, methane, and chlorofluorocarbons (CFCs).

Gases which cause a greenhouse effect within the earth's atmosphere and are therefore responsible for global warming and climate change. The most damaging are carbon dioxide (CO₂), methane (CH4), nitrous oxide (N2O), sulfur hexafluoride (SF6), hydrofluorocarbons (HFCs) and fluorocarbons (PFCs).

Gases in the Earth's atmosphere that produce the greenhouse effect. Changes in the concentration of certain greenhouse gases, due to human activity such as fossil fuel burning, increase the risk of global climate change. Greenhouse gases include water vapor, carbon dioxide, methane, nitrous oxide, ozone, and various forms of fluorocarbon gas (used in air conditioners and refrigerators).