the other gases hydrofluorocarbons hfcs perfluorocarbons pfcs and sulphur hexafluoride sf account for less than but their total emissions are growing these gases differ in terms of their warming effect and their longevity in the atmosphere apart from these six ghgs there are several other atmospheric substances that lead to warming eg chlorofluorocarbons or cfcs and black carbon see box or to cooling eg sulphate aerosols