He has a professional climate change denier[1] being trial-ballooned to run the EPA.
I think of all the question marks about Trumps seriousness and commitment to specific policy areas (and there are lots -- the guy is a blank slate), environmental issues are the least uncertain. The guy is a straight up head-in-the-sand opponent of anything that looks or smells like it might be one of those hippie "clean" things.
[1] Literally! Myron Ebell's day job is to write papers for a conservative think tank "debunking" climate science.