Every totalitarian system tries to get rid of its naysayers and critics. Imprisonment is a potent tool. Gets rid of them immediately. China knows that the Nazis knew that, the Soviets knew that, and a huge number of dictators have always known that. the next step is killing them. Is that where we are headed? How was ISIS different from that?
The risk of severe sanctions including imprisonment for climate skeptics is no longer a purely hypothetical risk, though some academics worry punishing public climate wrongthink may impact free speech.