What an ordinary person does — as consumer, voter, or participant in public discussions — is too inconsequential to affect either the climate or climate-change policymaking. Accordingly, if her actions in one of those capacities reflects a misunderstanding of the basic facts on global warming, neither she nor anyone she cares about will face any greater risk. But because positions on climate change have become such a readily identifiable indicator of ones’ cultural commitments, adopting a stance toward climate change that deviates from the one that prevails among her closest associates could have devastating consequences, psychic and material. Thus, it is perfectly rational — perfectly in line with using information appropriately to achieve an important personal end — for that individual to attend to information in a manner that more reliably connects her beliefs about climate change to the ones that predominate among her peers than to the best available scientific evidence. (Dan Kahan, “Climate-Science Communication and the Measurement Problem”)
Kahan’s empirical claim is that disbelief in global warming or evolution is not evidence of scientific ignorance. If you separate groups on a left/right basis, belief in warming increases with increasing scientific intelligence in the group predisposed to believe in it (left), decreases with increasing scientific intelligence in the group predisposed not to believe in it (right). Similarly with evolution if you divide the groups into more or less religious. The effect is shown in these graphs, where “Ordinary Science Intelligence” is a measure of to what extent someone understands how science works.
There is “solid evidence” of recent global warming due “mostly” to “human activity such as burning fossil fuels.” [agree, disagree]
His explanation ...:
If that person happens to enjoy greater proficiency in the skills and dispositions necessary to make sense of such evidence, then she can simply use those capacities to do an even better job at forming identity-protective beliefs.
The article has lots of interesting stuff in it. Among other things, if you test people to see how much they understand about the theory of evolution, those who believe in it do no better than those who don't. Similarly for global warming.
That fits my observation. Back before I gave up on arguing climate change issues on Facebook I concluded that almost nobody there on any side of the argument understood the mechanism of greenhouse gas warming. They thought of CO2 as an insulator, like a blanket. If that were all it was it would block incoming heat from the sun as well as outgoing from the Earth. The essential characteristic of a greenhouse gas is selective transparency, the fact that it is more transparent to the short wavelength light coming down from the sun than to the long wavelength light going up from the Earth.
The ignorance is not limited to Facebook. There is a video online that purports to demonstrate the greenhouse effect with a simple experiment performed by a young student. What it actually demonstrates is that CO2 is less transparent than ordinary air, not that it is selectively transparent, which is what being a greenhouse gas requires. The video is presented by the Cleveland Museum of Natural History and the Clean Air Conservancy.
The same pattern of how people choose what to believe was described in more detail in an old post by Scott Alexander about the way in which beliefs and attitudes tie into ideology. Each side of the political spectrum has a view of the world. When something happens that makes a good fit with one side's view that side pays a lot of attention to it, the other does its best to pretend it never happened. When something more ambiguous happens, each side interprets it in a way that fits their narrative. Someone's attitudes on issues ranging from global warming to Ebola can, to a considerable extent, be predicted by whether he self-identifies as conservative or liberal.
The Red Tribe and Blue Tribe have different narratives, which they use to tie together everything that happens into reasons why their tribe is good and the other tribe is bad.
After giving an imaginative account of how global warming should have been presented if the objective was to play into the conservative narrative instead of the liberal:
If this were the narrative conservatives were seeing on TV and in the papers, I think we’d have action on the climate pretty quickly. I mean, that action might be nuking China. But it would be action.
I blame the media, I really do. Remember, from within a system no one necessarily has an incentive to do what the system as a whole is supposed to do. Daily Kos or someone has a little label saying “supports liberal ideas”, but actually their incentive is to make liberals want to click on their pages and ads. If the quickest way to do that is by writing story after satisfying story of how dumb Republicans are, and what wonderful taste they have for being members of the Blue Tribe instead of evil mutants, then they’ll do that even if the effect on the entire system is to make Republicans hate them and by extension everything they stand for.
Which demonstrates that the Scott understands the logic of situations where individual rationality fails to produce group rationality.
Kahan’s conclusion applies to himself as well as to others. One of his questions to test knowledge of warming was whether “human-caused global warming will result in flooding of many coastal regions.” He took it for granted that the answer was “yes.” In fact, the high end of the range for the projection of global sea level rise by the end of the century in the high emissions scenario of the fifth IPCC report is about a meter, less than the difference between high tide and low. Kahan had accepted exaggerated claims by the side of the global warming controversy that prevails among his closest associates, the one that it could have “devastating consequences, psychic and material,” for him to reject.
This is fantastic, right until the end. A meter of sea-level rise *will* cause more flooding in many coastal regions. The rise doesn't happen only at low tide. High tide will be that much higher. (As will storm surges, etc.)
But I love the larger point. I've gotten the most hate for https://www.losingmyreligions.net/ from people angry about the environmental chapters. And there are people who agree with it but won't put up a public review because they don't want to be associated with those views.
Interesting graphs. Couple of observations:
* Very stupid people's opinions actually seem to slightly negatively correlate with those of their group! I.e. unintelligent people in religious communities are *less* likely to be religious than unintelligent people in non-religous ones. That's very weird- possibly a statistical artefact that isn't really supported by the data. Or are very unintelligent people unusually contrarian?
* If the two tribes are of equal size, it looks like unintelligent people mostly get the answers wrong, averagely intelligent people very slightly skew correct, and very intelligent people skew correct slightly more (although not nearly as much as one might hope). Assuming intelligence is itself uncorrelated with tribe, it looks like overall correctness does increase with intelligence (if right-wing and religious people are significantly more intelligent that might not be true). This is because the effect of increasing intelligence is stronger for the tribe with the correct answer than the tribe with the wrong one (which make some intuitive sense).