Climate change denial seems to spring from a mix of two things: 1) conservative tendency to be knee-jerk anti-science about everything, since it does not fit their desired world view of evolution, abortion, and similar issues. There is a history of science repeatedly coming up on the side of the left on these issues, over many decades, if not longer, and I think the right, particularly the religious right, resents science, as an institution, because of it; and 2) for big business it means increased cost of abiding by regulation designed to arrest and reverse any man-made contribution.
We've seen this week the religious and big business sides of the GOP at odds with one another on the religious rights bill in Indiana. and you know that the business side of the party is constantly banging its collective head against the wall that the religious right keeps tethering the party to social issues that make it harder to get pro-business candidates elected.
Climate change denying, or at least climate change doubting, is the one issue where both sides of the party can seem to coalesce, albeit for different reasons.