Very good article into how they think, and their hypocrisy.
btt
Fanatics are always sincere, and show an unlimited credulity towards their leaders. Any liars in the global-warming movement are at the top. Even they might be lying to themselves.
Con men tend to respect people who see through their shinola. If you play them right, they'll admit the truth to you and even offer you a place in the con. Not so for the people who lie to themselves. Instead, they show a certain obtusity with respect to the truth. Instead of "all right, you got me", they tend to fog out or unveil a talking-point somewhat robotically unless they're polished and practiced at mollfying skeptics.
If you haven't, you should read The True Believer by Eric Hoffer. It's a short book, but packed with profundity.
Some cult leaders are "sincere" psychopaths.