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).
