It's not just that. There's a religious component to it (only God can alter the Earth so dramatically, or Jesus is returning soon so it doesn't matter, or similar) as well as an ideological component (mitigating climate change can't be done with laissez-faire approaches).

At this point, it's self-reinforcing. One of our two major political parties has climate change denial as a fundamental part of its identity. Lots of people vote for that party because they share that belief. Those who benefit from that party's success are then motivated to spread that belief even further just to recruit more voters to the cause. And as that belief solidifies among their voters, the party becomes unable to change its position no matter how convincing the facts become.