Greenhouse gases are those gases in the earth’s atmosphere that trap the heat from getting escape back into space and, instead, reflect it back to the surface of the earth. As they produce a greenhouse effect in trapping the heat, they are called greenhouse gases. Greenhouse gases consist of gases such as carbon dioxide, ozone, water vapor, methane, nitrous oxide, chlorofluorocarbons, sulphur hexafluoride and other fluorinated gases.