Several commentators have noted recently that the GOP is the only conservative party in a democratic state which denies the science of climate change. This has occurred since 2008, when John McCain supported cap and trade. While some of their motivation obviously revolves around the economic importance of fossil fuel industries, conservative parties in other countries with similar economic structures (Australia and Canada are the analogies) have shown more flexibility on the subject. Why?
I would suggest a number of reasons:
1. The importance of money in US elections, particularly after Citizens United: Campaigns are regulated more stringently in other countries. Contributions are a great way of enforcing the party line on this and other issues.
2. The role of evangelical right-wingers: There are climate change deniers in this country who base their views, not on science, but on their understanding that God promised no more great floods in the Bible. These kinds of opinions are less prevalent in other, less religious countries.
3. America has more small government DNA due to its history: Australia and Canada did not fight a war for independence against what was perceived to be an oppressive central government. Any solution to climate change will inevitably require an increase in the size of the state, which is anathema to the GOP unless it involves the military.