These climate models are FUBAR, and a scientist with any integrity would divulge this up front. What they are left with is "we have no idea what the climate will be like ten years from now" - but it is likely to be much the same as it is now - yawn! As it was 50 years ago by my limited experience.
GW from CO2 and increased CO2 is a pretty well-tested theory. The simplest models are just a small slice of atmosphere and the radiation is calculated and more is trapped as more CO2 is added. The models you are talking about are global circulation models that are too coarse (in both time and space) to properly model weather. So they are fed parameters instead of figuring out the weather. But the weather will change with warming (see Eschenbach's writings). Also the models don't consider external influences on weather, like the Russian heat wave caused by blocking which can be caused by our current low solar ultraviolet levels or other solar/celestial factors (the link is imprecise but real and there is no link from CO2 to blocking).
So the models can easily be jiggered (by the parameters) to match whatever temperature series they want, both backwards and forwards. It is simple GIGO.
In other words, their computer models are the computational equivalent of an unreplicable experiment. The cold-fusion duo, Pons and Fleischmann, got hoofed out of the scientific pale because their results couldn't be replicated.
Is it I, or is there some sort of double standard here? Why is it that two guys who promised to help solve the energy crisis got the old-fashioned heave-ho, while a tight-knit citation circle of doomsayers get the new-fashioned coddle for substantially the same lacuna?