You said "as more water is added, wet air gets less dense; causing CO2 to settle faster on the ground -> if CO2 is a greenhouse gas, then it is sitting on the earths surface only, not in the atmosphere. The upper atmosphere can only be mostly dry and wet air and lighter gases."
The reason why "not a single paper I have come across bothers to deal with it" is because it is simply not the case. CO2 in the atmosphere is not all "sitting on the earths surface only". As I said, if this were the case, we would all be dead.
As for CO2 following temperature in the earth's geological past - there is a very simple explanation which you have conveniently ignored - as the temperature went up due to say an inter-glacial period cause by a Milankovitch cycle, the oceans warmed and CO2 was expired into the atmsophere. (Less CO2 is able to be dissolved in warm water.) The oceans are a vast CO2 sink. I think that is about the 50th time I have explained it here on HC.
Lighthouse, I will try and be diplomatic here - don't you think your time would be better spent learning about the science of climate change rather than postulating scenarios which are not based on reality or fact? I believe we are all interested in finding out the true facts of the matter, no matter what our political persuasion or our stance on climate change.
