If you care to ready "Dark Money" by Jane Mayer, you'll see that a very organized network of think tanks funded by billionaires like the Koch Brothers hires people to create blogs, assert falsehoods as if they were true, and generally counter any narrative that might win support to strengthen the EPA or any regulatory agency that might cut into the huge profits that corporations now take as their "birthright." After all, they have won "citizen" status and become enshrined in the onerous Supreme Court ruling known as "Citizens United." Ultimately that ill-named ruling allows corporations the right to purchase political muscle... sans apology.
When mass media carries hundreds of TV stations (most owned by the same SIX Titan Broadcast corporations), there's more disinformation than truth being relayed to people/viewers 24/7.
Thus in an atmosphere utterly thick with deception, it's impossible for most viewers to separate truth from fiction. I've made the analogy before that what passes for "food for thought" is just as tainted as real food. In both instances, the genuine article has been so thoroughly melded in with the counterfeit, that never again shall the twain be separated.
The result is that people think they are entitled to both their own opinions and their own truths. Consider that probably 40% of Americans do not believe in Evolution and take the Bible for absolute truth. Small wonder that many from that faith-based persuasion might question the truth of global warming.