However, the problem is that the direct, 'bare' effect of CO2 can be calculated, but there is considerable uncertainty in the net effect when feedback effects are included.
The climate modelers assume a large positive feedback, because it suits their purposes, but it could be negative, thereby reducing the effect of CO2 well below the levels assumed by the AGW activists/'scientists'. A small temperature increase can increase the humidity, thereby adding water-vapor effects to the CO2 effect, but the increased humidity can also increase cloud-cover which blocks the sun and thus reduces the effect.
No-one knows whether it is positive or negative, but the best guess IMO is that the feedback is NEGATIVE in the tropics and positive near the poles. This would give a net negative effect since most of the outward IR radiation is coming from the warmest regions of the globe.
Thanks for the detailed reply - my scientific background is well-removed from atmospheric physics, but I still follow what I can of it because of the political implications there.
I’ve always been suspicious of the feedback equation - not just because it seemed like the sign of that particular coefficient was chosen to give positive feedback, but also that its magnitude was conveniently large enough to give a significant warming increase, but not so large as to imply an irreversible runaway affect.
I’d never seen anyone propose that the feedback might vary with latitude. For what it’s worth, I think that’s a really neat approach, and I hope you have some success chasing it down.
And especially thanks for plugging away at the problem objectively in the face of whatever political crap you folks in the field have to deal with.