With regards to climate change, most people are living in cognitive dissonance ("bad conscience") -- we know that things are really bad, and that we're a big part of the problem, but we do not want to act accordingly.
That makes it very easy for naysayers and people with an agenda (big oil/coal/gas) to sabotage any public relations effort. I.e. if you tell people "it's not that bad, it's all fake news, etc." they're more than ready to believe you because it relieves their cognitive dissonance.
Also, the main driver here would be consuming less, a lot less, and that goes directly against the grain of market capitalism, which is founded on blatant consumerism, as well as "romantic consumerism" (e.g. you have to travel to foreign lands in a jet plane to be a truly complete person).