I don't think you got it right, the rate of warming depends on the concentration (i.e. the total amount) of GHGs in the atmosphere, not the rate at which they're emitted. GHGs basically reflect (actually absorb and re-emit) some of Earth's thermal radiation back to the surface, they act as an "insulator" (a greenhouse) just by being there.
https://en.wikipedia.org/wiki/Greenhouse_effect