It’s a hoax and a pseudo-scientific/pseudo-religious cult. It has brainwashed billions of people.
Dr. Tim Ball: The Deliberate Corruption of Climate Science.
Still in print on Amazon.
Encouraging to see a candidate expressing skepticism so strongly, but I still don't trust him any farther than I can throw a Buick. He made his fortune with a stock market fraud, and now he's after bigger game.