Do you think Trump calls climate change a hoax because he believes that?

Trump is the best illustration of the Dunning-Kruger effect.

The issue is that society gets information about climate from the media, not from scientists. Furthermore, the media, with an end goal to appear to be fair-minded,

frequently line up one climate scientist against one denier to discuss their point. However, that doesn't imply that mainstream researchers are divided into equal

parts on climate change. As a matter of fact, it's more similar to 97/3." We'll let you guess what direction.

Isn't it because he wanted to support the coal mining industry over there?

I think it’s because it’s inconvenient to him as a businessman for that to be true. 

He doesn’t understand it, so he’s not in any position to believe it or not.

Even Donnie T himself has no idea what he believes.

It's one of the benefits of variable policy.

He's not even sure if he is still President.

It's difficult to know what a guy who lied 30,000+ times in 4 years really believes. It's probably safer to assume he's being dishonest for one reason or another.

You mean is he stupid or opportunistic? 

.

Bit of both 

I don't think even Trump knows what he really believes.  He answers every question the way he thinks will get him the most attention.  He might say climate change is a Chinese hoax one day, and the next day say it's our most pressing problem. 

What Trump believes is irrelevant. It's like wondering what Hitler believed.