I think the best way to de-Hitlerise this discussion is to observe that the worst excesses of human behavior towards other humans have been instigated by people who have been able to convince their followers that they are in possession of the "revealed truth" contained in some grand mystical theory and that therefore their beastliness is sanctified by the "the ends justify the means" argument.
German Fascism, Russian (pre WII) and Cambodian Communism are three examples of religions that did this, killing millions for their version of the greater good. Like others, I detect in Greta Thunberg that same messianic zeal that is quite capable of perverting Environmentalism into a homicidal, dictatorial, depopulation movement.
If I am right, the next stage is to proscribe all non carbon neutral recreational activities.