In most countries the public "believes" in climate change. But it don't matter: People still consume much more than the planet can bear. Because they like to consume. And because they don't want to change "if no one else does it" (tragedy of the commons). So you're asking the wrong question (maybe not for a US audience, I give you that). The real question would be: How to change the behavior of a population? My best guess would be: by reforming capitalism (and/or democracy), e.g. carbon tax (imo best way would be that there's a second currency next to money for the carbon effect of every good/service). But good luck with that.

Disclaimer: For myself, I do believe in personal changes, e.g. consuming less (red meat, flights, gas etc). Not because it makes a big impact but because that's just my personal morality and it makes me feel better to do it. On a societal level it's tougher because most/many people's brains don't work like that (I think).