Stopping debate on a question before you're convinced that anyone can know the answer

The marvellously asymmetrical Megan McArdle, who's guest-blogging at InstaPundit, strikes me as a smart and articulate and appealing person. I don't know the details of her education in science, but I don't find it implausible to presume that it exceeds my own. And perhaps in this post, Ms. McArdle expressed herself with less than her typical care — trying to get into that "Insta" mode? But I have two reactions to this bit:

I think there are a lot of questions about global warming: how much, and what, should be done. However, I regard two questions as basically no longer worth debating, at least by people with my level of science education:

1) Is AGW [Anthropogenic Global Warming] happening?
2) Should we do something about it?

The first is a technical question that seems to be largely settled; when you've convinced Ron Bailey it's happening, you've convinced me.

First reaction: If you genuinely have a thorough-going education in the science relevant to issues regarding claims of dangerous man-made global warming (a phrase I'm using without at all accepting its premise, mind you), then why does your being convinced depend on proponents of the theory convincing someone else, be that Mr. Bailey or anyone else? Isn't that another way of saying that you don't have the thorough-going education in the relevant science? (In Ms. McArdle's case, I reject the alternative explanation, which is laziness.)

Second reaction: My own training and profession includes evaluating highly credentialed "experts" in all sorts of subjects daily. Specifically, I examine, and sometimes cross-examine, them with an eye toward helping jurors (and me) understand the gist of what they're saying, and usually with an eye toward either supporting their credibility or else pointing out reasons why their expert conclusions ought to be suspect (even to jurors or other non-experts who lack their expertise).

I don't have to be a climatologist, for example, to understand this two-part argument made by some well-credentialed climatologists: First, current science is still a long way from having any thorough-going understanding of the mechanisms of long-term climate change or short-term weather, and such understanding as we do have can lead to calculations that tie up the most powerful supercomputers for weeks on end. Second, the margin of error for the extrapolations being made from the very limited amount of genuinely reliable historical data on weather and climate which we do have substantially exceeds the degree of climate change being postulated as attributable to man-made causes (as opposed to climate cycles that have occurred before man could even arguably have much affected them).

That amounts to an argument being made by some (granted, not all) well-credentialed scientists to the effect that not even well credentialed scientists have enough reliable data to be sure enough about the conclusions of dangerous man-made global warming theory proponents to justify turning national economies upside down over it. Even more succinctly: At least some presumably smart scientists are saying, "Ain't none of us smart enough yet to bet the ranch on this stuff, and we don't have the data of sufficient reliability that we'd need if we were."

Until someone persuades me that that is wrong, I'm not going to bet the ranch based on Al Gore's or [fill-in-the-blank with the name of your favorite smart person or "expert"]'s say-so. I'm more than a bit worried that doing so would be like betting my health on an expert who prescribes radical treatments to readjust my phlogiston or chakra balances, or to vent some of my admitted ill humours (I'm especially prone to an excess of splentic black bile).

And precisely because Megan's own professional expertise is, broadly speaking, the value of the ranch which is being bet (economics), I'm surprised that she's willing to, either. She writes: "I think America needs a whopping big carbon tax (and am braced for the flood of mail I know this declaration will trigger)." Oy. Count me as whoppingly-bigtime opposed. But I do generally agree with her observations about the unlikelihood of political solutions to the problem, if there indeed is one.