The Kyoto Protocol lists six such materials, including CO2, methane, nitrous oxide, hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), and sulfur hexafluoride (SF6). Of these six, CO2 is easily the one most produced by human activity. But when it comes to potential for creating the greenhouse effect, the other five gases are all far beyond CO2.
在京都議定書規定管制的六種溫室氣體中，人類排放二氧化碳的數量最龐大，但論起造成溫室效應的潛力，其他五種氣體都遠高過二氧化碳。