GREENHOUSE GAS (GHG)

A gas that absorbs infra-red radiation (i.e. the sun’s heat and energy) in the atmosphere. Greenhouse gases include water vapour, carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), halogenated fluorocarbons (HCFCs), ozone (O3), perfluorinated carbons (PFCs), and hydrofluorocarbons (HFCs). These gases contribute to the ‘greenhouse effect’.