Greenhouse gases are those that absorb and emit infrared radiation in the wavelength range emitted by Earth. In order, the most abundant greenhouse gases in Earth's atmosphere are:Water vapor (H₂O) Carbon dioxide (CO₂) Methane (CH₄) Nitrous oxide (N₂O) Ozone (O₃) Chlorofluorocarbons (CFCs) Hydrofluorocarbons (incl. HCFCs and HFCs)