I am not quite sure of your point. So more CO2 increases the temperature of the atmosphere and eventually the temperature (and the acidity) of the oceans. The warming also increases the release rate of methane. As the atmosphere and the oceans heat up, more water vapor enters the atmosphere. Now we have CO2, Methane and water vapor at higher concentrations in the atmosphere and heating accelerates. The glaciers and ice caps melt, resulting in even more surface to absorb solar radiation.

Any way you cut this, humans are driving unprecedented warming of planet earth, and we must stop using fossil fuels ASAP (or in any event, we will soon run out of them anyway). Once fossil fuels are gone, we will have no way to support 8 billion humans on earth, and the earth will be much less hospitable to life in any event. Not a good scenario.