I have a vague idea how believing in a flat earth may work. (Not enough to write it down)
But it still irritates me that an appreciable fraction of the general population in the US deny that climate change is caused mainly by human influences. Even more so as it seems to be a fraction large enough to be politically relevant.
I see that this question has a strong political connotation, which is opinion based. But that is not part of the question.
It is somehow culture-related, as it's different in Europe, at least in Germany.
I would expect it is a fringe group like people assuming a flat earth. There is a related, but different kind of group. People denying that the Holocaust happened. This has a strong political association to extreme right groups.
Is assuming flat earth and denying climate change the same kind of phenomenon?