CFC vs greenhouse gas

CFC and greenhouse gas both are nouns.

Word	Noun	Adjective	Verb	Adverb
CFC	Yes	No	No	No
greenhouse gas	Yes	No	No	No

As nouns, greenhouse gas is a hypernym of CFC; that is, greenhouse gas is a word with a broader meaning than CFC:

CFC: a fluorocarbon with chlorine; formerly used as a refrigerant and as a propellant in aerosol cans
greenhouse gas: a gas that contributes to the greenhouse effect by absorbing infrared radiation

Other hypernyms of CFC include pollutant, fluorocarbon, greenhouse emission.

CFC (noun)	greenhouse gas (noun)
a fluorocarbon with chlorine; formerly used as a refrigerant and as a propellant in aerosol cans	a gas that contributes to the greenhouse effect by absorbing infrared radiation