According to various reports of the Intergovernmental Panel of Climate Change (IPCC), the so-called anthropogenic radiative forcing can be related through a linear relationship to the global mean equilibrium temperature change at the surface by ΔT_s = λ* RF, where λ* is the climate sensitivity parameter. This parameter is the reciprocal of the climate feedback parameter λ commonly used in the global energy balance model of Schneider and Mass (1975). In my presentation I will discuss the pros and cons of this model. I will also demonstrate that its solution differs from the equilibrium temperature derived from the planetary radiation balance relation. This equilibrium temperature also serves to quantify the greenhouse effect. I will argue that this commonly accepted quantification of the greenhouse effect is rather insubstantial.