Is ‘I don’t have an opinion on AGW’ a valid scientific position?

In amongst the sound and fury which accompanied last week’s fight to the death between Phil Plait’s Bad Astronomy and Steve McIntyre’s Climate Audit in the 2007 Weblog Awards (which was eventually declared a draw), I noticed an interesting attitude amongst the Climate Audit supporters invading certain threads around here (the more polite ones, anyway). In response to the characterisation of McIntyre as a ‘AGW (anthropogenic global warming) denialist’, most argued that he offered no opinion on the question of human influence on the climate, and furthermore, that this was a good thing. For example:

Well no. He makes no statements about [AGW] and rightly so, because he only makes a statement about something that he checked thoroughly. So he doesn’t deny it nor confirm it.


We were also pointed to this (somewhat dated – note the reference to the 2001 IPCC report) statement from McIntyre himself (my emphasis):

Does your work disprove global warming?

We have not made such a claim. There is considerable evidence that in many locations the late 20th century was generally warmer than the mid-19th century. However, there is also considerable evidence that in parts of the Northern Hemisphere, the mid-19th century was exceptionally cold. We think that a more interesting issue is whether the late 20th century was warmer than periods of similar length in the 11th century. We ourselves do not opine on this matter, other than to say that the MBH [the original Mann et al. hockey stick paper]

I find this attitude rather curious, not least because it takes the idea of scientific neutrality to rather ludicrous extremes. “I don’t know” is, of course, a perfectly valid scientific position – but only in the absence of any data. Take dark matter, for example: we have many observations that suggest that what we see out in the cosmos is only a small fraction of what’s actually there, but we have no data regarding what the rest of it might be composed of. So cosmologists are perfectly justified in admitting that they don’t know what dark matter is*. In contrast, we have plenty of data pertinent to climate change; and the idea that someone who, for better or worse, has spent a large amount of time and effort ‘auditing’ climate data has absolutely no opinion on what it all means strains the limits of my credulity somewhat. In science, you should start off sitting on the fence, but the whole point of research is to work out which way you should jump.
It is also clear that McIntyre does have opinions on at least some aspects of the AGW debate, even if he chooses not to articulate them. Scientists will not devote time and effort picking apart other scientists’ data and methods unless they believe them to be flawed. Thus the targets of McIntyre’s ‘auditing’ indicate that he has some doubts regarding the accuracy of instrumental records which indicate a rapid increase in average global temperatures in the past 25-30 years (given these); and that he’s a tad (just a tad, mind) sceptical about proxy records that indicate that this warming is unprecedented in the last few hundred years, and possibly the last millennium, although I’d argue this issue is somewhat tangential to the question of what’s happening to the climate right now**.
I think it’s this contradiction that raises suspicions of the motives behind Climate Audit. Scepticism is one thing, but by determinedly hiding behind a facade of studied neutrality, it’s hard to pin down exactly what McIntyre thinks is wrong with the current consensus (and the reasons, based on his understanding of climate science, why he things so), other than that he doesn’t believe it’s right. Does he think that the instrumental record is fundamentally flawed, or that it’s basically right but that its accuracy could be improved? Does he think that the Industrial Revolution has done nothing to the climate that wouldn’t have happened anyway, or does he think that we are warming the climate, but have yet to push it beyond the bounds of natural variability? Perhaps close reading of his site will eventually give me a better idea, but the fact that his criticisms seem fairly divorced from any discussion of their possible impact on the wider scientific picture mean that out-and-proud denialists can project their own certainties onto his doubts, and suddenly the Climate Audit project is demolishing the whole edifice of the AGW consensus, rather than contributing minor refinements. And suddenly, rather than grappling with important questions like what, if anything, we should be doing about our inadvertent CO2 forcing experiment, we’re having a rather more pointless debate over what should be indisputable: whether we’re having an effect at all.
*and even in this case, they’re likely to have an opinion on what it might be. How else do you guide your research programme?
** I find the conflation of these two arguments extremely annoying – the question of whether “hockey stick” reconstructions are flawed has very little bearing on the question of whether humans are materially affecting the present climate.

Categories: antiscience, climate science

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