There's been a very well coordinated propaganda campaign around climate change denial. This campaign improved upon the tactics that tobacco industry lobbyists used to deny the connection between smoking and cancer.

In particular, by tying climate change denial to political identity, and casting climate research as immoral for its lying, it created a passionate base of climate change denalists to call into every radio show, to swarm message boards, and to harass those who speak publicly about climate change.

If you can listen to podcasts, the best summary of this is from the Drilled podcast, in my opinion:

https://www.criticalfrequency.org/drilled