yes water vapour is a very powerful green house gas, infrared is is radiated from earths surface and nothing else in the earths atmosphere stops as much of the suns energy reaching the earths surface as clouds do.. plus the cooling effect of evaporation. my point is water forms it’s own equilibrium so to speak if it didn’t we would have a runaway greenhouse effect from the thousands of cubic kilometres that evaporate ever singe week of the year.
