The NYT had a very good article on how the fossil fuel industry and other rich donors got the Republican party to be committed to denying the reality of global warming, Unfortunately, the article carried a headline that asserted the Republicans "view" climate change as fake science.
There is nothing in the article to indicate what Republicans actually believe about climate change. There is no reason not to assume that the Republican leadership believes anything different about climate change than the vast majority of educated people in the United States. The article explains how in order to advance their careers in politics they have an interest in denying the reality of climate change. It says nothing about what they believe to be true.