You're getting stupider by the minute.
CO2 feeds the greenhouse effect. The radiative forcing factor for the amount of CO2 present in the atmosphere is, as you know, calculable. The net sum of such forcing factors is sufficient to produce the observed warming. Your idea that CO2 cannot initiate warming but can only reinforce it is simply unsupportable - and you've really made no attempt to do so anyway. The behavior of the Earth's climate in the geological record does not restrict what processes can take place. The record only tells us what processes HAVE taken place.
No other candidate exists that could have produced the observed warming. Isotopic analysis shows that the CO2 added to the atmosphere during the Industrial Revolution is almost entirely from the human combustion of fossil fuels.
The world's climate scientists - thousands of PhDs actively conducting research in this topic - agree that human GHG emissions is the primary cause of the observed warming. They know this topic far, far better than do you. I'm going with mainstream science.