Knowledge itself is inevitable. You cannot control every single person's desire to know more and advance knowledge. I lived in 1980's Romania and the state tried everything it could to suppress knowledge about the outside world. People still found out things they were not supposed to know about. (An ironic example - the Romanian religion scholar Mircea Eliade died in exile during the 1980s. The Romanian state did not mention anything... and the next morning everyone was talking in the bus and at my high school. We were not even supposed to know this person existed...) I don't know if you realize, but you are cherry picking the subjects which we can talk about (climate change) versus the subject which we cannot talk about (nuclear power, WWW).