Considering that they can’t seem to get global warming straight, I’ll reserve judgement on anything more complicated.
I would reserve judgment, too. But "Global Warming" is much, much more complicated. This is basic physics. We can attempt direct measurements and model the mathematics on the back of an envelope. The conceptual hurdles required for the human mind to grasp the physics are far more daunting than the cartoonish caricature of "Global Warming" presented by Al Gore and the mainstream media.
Global Warming Theory involves a string of concatenated hypotheses (what was it Willian of Occam had to say about these?), some of which are straightforward basic physics (e.g., carbon dioxide absorbs infrared radiation) and easily validated. Some of the hypotheses associated with GWT, are dependent on tenuous and poorly understood large scale atmosphere physics and involve critical parameters whose values are not known with enough precision to reliably even predict the sign of their effect.
A simple analogy might be eclipses and rain. Astronomers can reliably predict eclipses 10,000 years into the future. Meteorologists cannot tell you if it is going to rain two weeks from today. Basic physics is like astronomy; GWT is like meteorology.