[_delirium]

In my case, I'd be more skeptical of AGW if there were better theoretical explanations of how large changes in atmospheric CO2 concentration might not cause macroscopic climate changes. As far as I can tell, most of the debate is over the instrumental record, i.e. an argument that as an empirical fact, warming isn't happening. But we do know that CO2 concentrations have increased (I don't think those measurements are controversial), and as far as I can tell the theoretical understanding is that this ought to produce a warming effect. Are there contrary theoretical models that predict that CO2 levels could increase at magnitudes approximately around those we see and yet not produce a warming effect? (Not a rhetorical question; I'm curious if there are.)