You might think there is little more to add here. But a new study in the Journal of Personality and Social Psychology, by Troy Campbell and Aaron Kay of the Duke University Fuqua School of Business, teases out a key factor that, while not inconsistent with many of the above explanations, definitely helps us better understand what is going on. Namely, the researchers show that Republicans reject climate science a lot more when they perceive it to support ideologically inconvenient policy solutions (like, say, the EPA's Clean Power Plan) than when they don't. In other words, the authors argue, this "solution aversion" feeds back into conservatives' perception of science itself.
The paper shows the significance of “solution aversion” through a series of four experiments -- the final of which also catches liberals engaging in the behavior. But first, let's look at this phenomenon as it manifests on the right.
In one of the paper's experiments, politically diverse research subjects were separated into two groups, one of whose members read about a climate change solution that involved regulatory action to reduce emissions (much like the EPA's approach), while the other group read about "how the United States could help stop climate change and profit from leading the world in green technology." Afterwards, subjects were asked how much they agreed that humans are causing climate change.
The result was that whether or not they'd read about a "free market" climate solution or a "government regulatory" climate solution, Democrats believed in the science of climate change about equally. But for Republicans, which solution they'd read about seemed to have a very big effect on their feelings about the science:
A similar result, incidentally, has been found by Yale researcher Dan Kahan and his colleagues: Framing climate solutions around either nuclear power or geoengineering (artificial interference with the climate system in order to slow the rate of warming, a technological fix) also seems to make conservatives more accepting of climate science. This is presumably because these solutions are also perceived as being based on the free market and individual ingenuity, rather than a command and control government regulatory approach.
Thus, the new paper definitely adds to the mountain of evidence suggesting that conservatives reject modern climate science because they think that it implies a series of policies that they find unacceptable. But interestingly, Duke's Campbell and Kay also show in the final study of their paper that liberals, too, can change their views of the facts because they don't like what those facts seem to imply.
In this last experiment, individuals were first asked for their opinions about gun control, and then either read 1) an essay arguing that the availability of weapons helps citizens fight off home intruders (an anti-gun control view) or 2) an essay suggesting that having guns around worsens intruder violence and deaths in home invasions (a pro-gun control view). Finally, the study subjects were asked about how severe they thought the problem of violent break-ins or home invasions actually was.
In this case, views about the home invasion problem seemed to swing wildly among gun control supporters depending upon whether they had been put in a pro- or anti-gun control state of mind:
In other words, gun control supporters -- liberals, we presume -- were less likely to take the problem of violent home invasion seriously if they had previously read an essay suggesting such evidence would favor a pro-gun or anti-gun control point of view. To be sure, whether this actually counts as a case of "science denial" depends on the actual facts at issue -- and there is reason to think that deadly gun violence in home invasions is relatively rare. Nonetheless, gun control supporters did see their views of the problem change depending upon their perception of the solution, suggesting a pretty clear case of "solution aversion."
Granted, the new study has its weaknesses. For instance, we probably shouldn't assume based on this paper that running out and singing the praises of clean energy and green tech, framed as a free-market solution, would actually work to depolarize the climate issue. Other research, for instance, implies that the issues of clean energy and energy efficiency have also become infected with partisan emotions, to a significant extent.
Still, it is very useful to bear in mind that often, when we appear to be debating science and facts, what we're really disagreeing about is something very different.