In addition to the other answers here, let me throw another one out there:

Republicans have been conditioned for decades now to never work with Democrats on anything, to the point that it wouldn’t be inaccurate to diagnose all of them with oppositional-defiance disorder. They don’t need (or want) to know why they are against the things they are; it’s enough to know the people they hate are for those things.

Democrats don’t deny the reality of the changing climate, therefore they must.