"Skeptic" carries with it a connotation of prudence, a studied approach to a question, but most of the self-styled anthropogenic global warming (AGW) skeptics have a tendency away from this, towards believing everything they hear, or at least everything that could be naively taken to mean that the climatological consensus is incorrect. There is thus a tendency towards a petulant "Gotcha!"-ism, whereby countless individuals with little technical training, who haven't searched the literature for explanations, and who usually haven't even reasoned quantitatively about their objection, come to believe that they've outwit the dozens of working scientists (paid skeptics!) who've devoted careers to this problem.
To a scientist, even one like myself who specializes in something else, this looks like bad behavior behavior. Coming from economists like Dwight Lee and Jeffrey Clark it could be called unprofessional intellectual misconduct--pure hubris!--to assume that climatologists have simply "ignore[d] what seems to be a warming trend on Mars." But, pace Dawkins, we should not assume the lay denialist (reflexive rejector of the thesis that Man is a significant contributor to global warming) to be wicked.
That's a difficult proposition. Whereas a few generally stick with a calm albeit premature bandwagonism, the norm is venom, perhaps motivated by the crank belief that AGW is a conspiratorial hoax devised as a backdoor route to socialism.
We must remember that both scientific humility and the capacity to be a skeptic regarding technical issues are learned, not innate. Most of the public does not understand quantitative arguments, even more are so confused about science that they can't distinguish good from bad, and treat bumper-sticker flim-flam such as "Mars is warming!" as as solid an argument as anything found in Geophysical Journal. The tendency to translate quantitative uncertainties to categorical ones--to take the basic truth that climatologists are not always 100% correct, that there are error bars, and that they disagree with each other at the margins as evidence that the AGW thesis itself is in doubt--is perhaps instinctual. Some carry with them another misconception about science itself, no doubt picked up in grade school, which causes them to doubt climatology beyond reason climatology simply beacause it is an historical and observational science. "Control group, experimental group, laboratory..." These folks will not be satisfied until an experiment is run on a separate Earth we have on reserve and, in 500 years, one is shown to have warmed. Years of miseducation compound with arrogance to make bringing people to at least make cogent arguments an uphill battle. How can someone who doesn't even understand science be brought to argue scientifically?
I can't answer that one, but for other would-be skeptics, I offer an algorithm of sorts for prudence and responsibility, and that will ultimately help their case if their argument turns out to have merit:
- Give a little thought to the nature of your objection, and then state it clearly. For example, "Mars is warming!", if taken to be a prospective argument contra AGW, is a statement that what climatologists call AGW is actually caused by the sun, since solar irradiance and solar activity are what Mars and the Earth have in common. Similarly, if the small error in US climate data uncovered last Friday would falsify AGW or reopen the scientific debate, it would mean that, after revision, the global mean temperature would contradict the models and attribution studies on which the AGW thesis is based.
- Check the FAQs. Many of the common arguments contra AGW have been addressed and most do not deserve repetition. Do your part in lowering the noise level by refusing to spread any objection that lacks merit. Informed layman (climate skeptic) Coby Beck has done much of your homework for you by compiling an FAQ entitled "How to talk to a climate skeptic." The IPCC report itself has an associated FAQ document; New Scientist magazine and the Logical Science weblog have also put up high-quality FAQs which reference the technical literature.
A weblog, Real Climate is maintained by a group of climatologists for the purpose of communicating with the educated public. Searching it with Google is usually a good way to find discussion of climate controversies. Had the angry mob waited six hours last Friday, they'd have found there a definitive argument for why the error uncovered by McIntyre was a molehill, not a mountain.
- If the FAQs don't hold an answer, search the literature.
This is a prerequisite for the next step, anyway, and it's been made ridiculously easy by Google Scholar, which indexes most academic journals. I have found it an invaluable tool in my day-to-day biophysics research.
- If the answer cannot be found in the technical literature, write your argument as if to convince an expert in the field. The best way to do this is to prepare an article for submission to a mainstream scientific journal, so that it will pass the BS-check that is peer review.
In short, think like a scientist.
It's been brought to my attention that it's somewhat difficult to be a bona fide lay climate skeptic, as most people don't have access to a university library and can't afford to purchase article after article. There are admittedly few resources for the intellectual self-starter other than the technical literature. Even the Wikipedia article on the Greenhouse Effect doesn't present the underlying physics in anything more than a qualitative fashion. Real Climate is perhaps the best source for the educated layman. but Real Climate, being a weblog, doesn't start from the beginning.
I can certainly lay a lot of blame on the "skeptics" for not doing their homework, for believing conspiracy theories about the scientists, for claiming (contra common sense) that they're statist shills, and for general bad behavior, but climatologists could stamp out a good deal of this if they made a better effort at explaining AGW's peculiar logical structure and its underlying physics to interested, quantiatively competent free marketeers. Reflexive deniers abound, but not all doubters are denialists, even if it appears as though they don't even bother to check their concerns against the literature. All the majority of the public sees are hand-waving, qualitative arguments, most of them coming from journalists and activists, not scientists. They don't necessarily know that there's any deeper to dig!