Kyoto basket includes these six greenhouse gases : carbon dioxide (CO ₂ ), methane (CH ₄ ), nitrous oxide (N ₂ O) and so-called F-gases (fluorocarbons and perfluorocarbons) and sulfur fluoride (SF ₆₎ . ). Each gas is weighted by its global warming potential and aggregated to give total greenhouse gas emissions in CO equivalents _{2 .}