First, I’m highly amused by the fact that the UN experts are at one time unequivocal that humans are causing GW, and simultaneously 90% confident. How can you be 90% unequivocal?

And how on earth did they arrive at the fudge-figure 90%?

(Seems to me that our experts want the public to be “unequivocal,” while leaving themselves ample wiggle-room. But that’s just my cynical self.)

Personally, I’m 90% sure that GW is a happening thing, but I’m very, very skeptical that humans are the primary factor driving it, as the UN-approved panel would have us “unequivocally” (or is it 90%?) believe.

For starters, there is a vast difference between “association” and “causation;” “plausible” is not the same as “proven;” “best guess” can only take into account what is known; and irrespective of what “scientific consensus” might be, scientific truth is not subject to the democratic process.

Also, the earth has undergone huge climate changes without human intervention, as in the ice ages, and we have a remarkable un-Earthly control in the planet Mars, which is itself undergoing global warming and link).

Now, the solar system is about 4.5 billion years old — what are the odds that Mars and Earth would pick this exact nano-instant of their respective histories to undergo global warming, for entirely different reasons, the Earth’s warming due to human activity, that of Mars due to “other” — like cosmic radiation, sun effects or “unknown”? — and how do we separate human influence on GW from other non-human influences?

But all that’s trivial.

It’s much more disturbing to me that by decreeing that GW is “unequivocally” the product of human agency, the panel have preempted any questioning of their findings. If it human agency is “unequivocally” responsible for GW, skeptics are either fools or knaves. This is a classic example of poisoning the well, a logical fallacy which seeks to discredit a skeptic’s motives, thus making his arguments dismissible even without considering the quality of his case.

One needs only to watch Mr. Gore’s movie “An Inconvenient Truth” to appreciate the lack of room he affords to skeptics who question the role of humans in driving GW, and to understand how deeply political — and downright nasty — the issue of GW has become.

When the UN panel declares it to be “unequivocal” that Global Warming is anthropogenetic, it is making a political statement, one designed to present one side of an argument as if it were incontrovertible when it is not. No scientific conclusion is unequivocal — if you need “unequivocal truth,” find it in religion.

In taking such a position, the UN leaves no room in the public’s collective mind for honest skepticism, no room for honest folks questioning the authority of their experts, their “90% certain” statement, buried deep in the article, not withstanding: in the public’s mind, which will be what determines policy, any disagreement will be perceived as dishonest, and to have come from the loopy fringe, from liars or from their dupes. At least that’s my reading of the article.

Such a position shuts down reasoned debate, and is itself the antithesis of science.

To me, that’s the important issue here — not what might or might not be causing GW.

Brian