The CO2 radiative forcing changes over the time periods you cite are far smaller than what would be caused by a doubling of CO2. (realclimate.org)
The climate sensitivity value tells us how much the planet will warm or cool in response to a given radiative forcing change. (skepticalscience.com)
radiative forcing a change in average net radiation at the top of the troposphere resulting from a change in either solar or infrared radiation due to a change in atmospheric greenhouse gases concentrations; perturbance in the balance between incoming solar radiation and outgoing infrared radiation (ipcc.ch)