Reducing the ability to shed energy will raise temperature just as surely as raising the power source.
CO2 raises the emissivity of the atmosphere....it doesn't reduce the ability of the atmosphere to shed energy...it increases it.
Without CO2 all the surface produced 15 micron radiation directly escapes to space at the speed of light. Maximum efficiency.
But you think the meagre portion that atmospheric CO2 finally released to space from high altitude and ~-50C is more than the surface 15 micron radiation produced at 15C which is totally absorbed within a few metres.
I suppose you need to believe the unbelievable to keep your bizarre theory of physics working.