OP is talking about people who reject climate change. If you know many, youll likely note most do not deny climate change but instead deny that it is man made, which is an easier delusion to maintain.
It depends on which subset we're talking about though. Some are quite well educated and (IME) lately have taken the position that sure, it's happening and sure, it's human caused but that mitigation is far too expensive and economically disruptive to justify. Thus that we should simply let things run their course and deal with any fallout as necessary.
They are starting from the conclusion of "I'm not going to lift a finger to do anything related to the climate, and the society shouldn't, either," and then they're working backwards to find arguments that justify their position.
See how easily these people switch from "Nothing is happening" to "Oops it's too late to do anything."
Your vehicle is traveling straight and there's debris in the road in front of you. If you swerve left there's an oncoming vehicle. If you swerve right there's a ditch and a power poll. You're going to hit something no matter what you do. Which is the least bad option?
It's entirely possible some of them are merely paying lip service and don't really believe that it will ever affect them personally. But taking them at their word they accept that they will be impacted one way or another.
I don't happen to agree with them but I still think it's worthwhile to understand other's reasoning. The dismissiveness that's all too common drives dogmatic behavior and polarization.