Greenhouse gases are those gaseous constituents of the atmosphere, both
natural and anthropogenic, that absorb and
emit radiation at specific wavelengths within the spectrum of infrared radiation
emitted by the Earth’s surface, the atmosphere and clouds.
This property causes the greenhouse effect.
Water vapour (H2O), carbon dioxide (CO2), nitrous oxide (N2O), methane
(CH4), and ozone (O3) are the primary greenhouse gases in the
Earth’s atmosphere. Moreover there are a number of entirely human-made
greenhouse gases in the atmosphere, such as the halocarbons and other chlorine
and bromine containing substances, dealt with under the Montreal Protocol.
Beside CO2, N2O and CH4, the Kyoto Protocol deals with the greenhouse
gases sulphur hexafluoride (SF6), hydrofluorocarbons (HFCs) and
perfluorocarbons (PFCs).
