Your idea is wrong--you still don't understand the greenhouse effect. Instead of saying that Elizabeth and I were answering the wrong question last time you should have tried to understand our answers. The more greenhouse gas molecules present then the greater the amount of energy returned to the planet's surface.
Try looking at Trenberth's energy diagram and understanding it. With no greenhouse gases then the downwelling radiation from the atmosphere would be zero, adding more gases increases the amount.
EDIT: The sun radiates energy at the Earth continuously--it's not like there's some fixed amount of energy that we're dealing with. Let's try a little thought experiment, where we start with an Earth like ours except without any greenhouse gases in the atmosphere, then slowly begin to add them.
Without any greenhouse gases in the atmosphere, after some time the Earth's surface will reach a temperature where it radiates away just as much energy as it receives from the sun. If you use the current solar flux and albedo then that temperature is something like 255 K. Now put a single water molecule in the atmosphere. Occasionally that water molecule will absorb a photon that was bound for space, stay excited for awhile, then radiate that energy away. A spectroscopist could tell you the details of all that--I'd have to research how long it takes and whether it has to collide with another molecule, etc.--but I think you accept that it does that. Now, since the diameter of the Earth is so large compared to the depth of the atmosphere, there is about a 50% chance that the photon radiated from the molecule will go to space and 50% that it will head back to the surface.
This process takes place again and again, and depending on how often it happens there will be a flux of energy from that water molecule that will ADD to the solar flux that the Earth's surface receives. That shifts the equilibrium temperature up ever so slightly from what it was before. Now add a second water molecule, since there are just two molecules in the whole atmosphere, we can think of them as independent, and that will double the effect. Three triples the effect and so on. Eventually (gigatonnes later) then they will start overlapping in their effective area and so the effect will not go up linearly--but it still goes up with the more that are added. We know that at current levels the effect goes up approximately logarithmically with concentration.
Note that these equilibria are determined from energy fluxes (power per unit area), not from a fixed amount of energy, so saying "No change in the energy" is not right.
Now let's think about this in terms of the Trenberth diagram. When there are no greenhouse gases, then the equilibrium flux from the Earth's surface would be equal to the flux from the sun, 341, minus what's reflected, 102, to give 239 watts per square meter. When you start adding in those water molecules, you increase the flux absorbed by the surface (239 + flux from one molecule, 239 + flux from two molecules, etc.), and you will also increase what's radiated from the surface. Outside the atmosphere it still has to be radiating 239 watts per square meter, but now that comes from the surface AND from the atmosphere. What you've done is change the INTERNAL equilibrium at the surface (and also at all the levels of the atmosphere).