I'm familiar with some of his statements, but I can't claim to know them all.

Could you please refer me to where he said that 'all climate change science is a hoax'? I would agree that would be a factually incorrect statement though I could not find anything where he said that. My interpretation of what I've read from what Trump has said, is that Trump believes that Climate Change Alarmists (from his perspective) utilize it to for political/policy reasons beyond the purely environmental reasons that they claim.

Trump and many other people don't seem to clearly understand the difference between the 'settled science' part of climate change and the 'unclear science' part. As such Trump and many others have very muddled and confused responses to those advocating various public policy changes due to climate change.

Some clarity about what is and isn't 'settled' would certainly improve the public debate on policy but I'm not holding my breath.