The credible scientific journals have long since noted that man–made climate change is not only a fact, but has been the consensus amongst climate scientists since 2004 (Science Magazine). Whilst I can just about imagine someone with no interest in the subject being ignorant of these facts, I do not see how it is possible that someone who has expressed interest is unaware of them, excepting the unfortunate psychological explanation.
On that psychological explanation: I do hope the deniers are aware that they’re regarded as a fruitful subject for psychological research, conspiracist ideation. The essential paper is behind a paywall, so here’s a blog where the authors discuss the matter.
My take is slightly different. If I am challenged by facts that contradict my belief, I will challenge those facts. That’s fair enough: no one likes being wrong. But part of being an adult is admitting to yourself that you may be wrong, so when the facts are plain I swallow my ego and admit my error, I hope. I have never, since my childhood, been so egotistical that I believe that because I can’t be wrong, then all those horrible facts must be the product of a mass conspiracy. Masses of people simply can’t keep a secret. If nothing else, human nature makes a genuine mass secret impossible; talking is a core part of being human, so people talk, so the secret gets out. That’s why people who subscribe to such theories are asserting those with whom they disagree are not subject to human nature, are not human: e.g. mass conspiracy theorists and their hangers–on are bigots.
And, beyond that, climate change denial represents a great failure of the political right. They have left the solution to others, rather than swallowing their pride and coming up with an answer that suites their belief. I do not recall in my history classes great conservative philosophers refusing to address questions that they did not like, rather I recall great conservatives shaping the answer to the distasteful problem in their image. Did Disraeli run away from Reform and assert reformists were mass conspirators? No, he faced the problem and chose the solution that did least damage to the right of the time. Why, then, do these current right–wingers not face the problem, why do they leave the solution to others? They shame themselves. The irony is a right–wing solution is not difficult, it’s clear and obvious: just change market regulation so actors clear up after themselves, then let the market get on with it. Yes, you’ve got the usual problems of policing regulation, etc., but so what? Regulation is solved problem.