Not at all ian...energy passing through hardly notices the CO2 molecule...it passes through like it wasn't even there.
You are correct that radiation in the Atmospheric Window bands escapes freely to space, almost as if the air was not there. But our topic is the bands where GHGs do absorb radiation. And then what happens to that absorbed energy.
Makes no difference...any energy that makes it through a so called greenhouse gas molecule in the form of IR is still moving freely into space...energy can not move spontaneously anywhere other than towards a cooler area.
IR does not warm the air...the air is warmed via conduction..therefore, the greenhouse effect, and all that you attribute to it is nothing more than model based fantasy.
And by the way...energy does not move back towards the earth via conduction either. Energy, in all its forms can only move towards a more disorganized state...never in the other direction...unless, of course, you are providing work to make movement towards a more organized state happen. No back radiation, no back convection, no back conduction..