From my perspective the difference between believers and non-believers is invisible.
Rivers stopped catching on fire in the US not because individuals decided to stop dumping chemicals into rivers, but because Americans took collective action in the form or regulations and fines to force better behaviour through financial consequences.
The reality is pollution is an externality, and a very invisible one. Individuals are unlikely to make decisions that impact it because they don't directly bear the costs. And the reality is our societies aren't structured to make it easy to avoid polluting. Try living in an average American city without burning gas in a car, or oil/gas to heat or cool your home. It's an impossible ask for a typical middle class family, let alone someone lower on the socioeconomic scale.
There's a reason things like carbon taxes and green subsidies are very attractive: it allows you to incentivize the behaviour we want to see by baking in the cost of those externalities into people's decisions.
Why would politicians tax energy usage if no people demand it? Why would politicians tax meat if no one demands it?
This kind of appeal to futility only brings change when consequences happen.
But when a large portion of the populace (and thus elected officials) doesn't believe there's a problem in the first place, it's a little tough to take collective action, which brings us back to the original point.