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 terrestrial radiation
emitted by the Earth’s surface, the atmosphere itself, 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). (1) The primary greenhouse gases in the Earth’s
atmosphere are water vapour, carbon dioxide, methane, nitrous oxide, and ozone.
[2] Greenhouse gas (GHG) is a gas, such as water vapour, carbon dioxide,
methane, chlorofluorocarbons (CFCs) and hydro chlorofluorocarbons (HCFCs), that
absorbs and re-emits infrared radiation, warming the Earth’s surface and contributing
to climate change. Greenhouse gases are gases as carbon dioxide, nitrous oxide,
methane, ozone and chlorfluorocarbons occurring naturally or from human
activities and are contributing to the greenhouse effect (global warming).
THE ABC FOR SUSTAINABLE CITIES
UNEP / UN HABITAT / FIDIC / GI-REC
