I think its because they see it as something that wont effect current kids WHEN they are kids. When they get older they can deal with it but right now they value the paycheck that keeps their kids fed over a shift in our energy economy. That is the argument anyway.

There are lots of idiosyncratic issues that ended up on one side of the political spectrum with little direct correlation to the advertised philosophy of the group. In the case of Climate this is due to heavy investment by fossil fuel within the media right leaning people consume.