You know how Hollywood and other media can lead people on the environment?
They can write characters that act environmentally as a matter of course–that is, without calling attention to it. Not to make an environmental superhero or character that makes a big deal about it.
Make characters eat sustainably, put sweaters on in the winter, bring bags shopping, take public transit, choose to vacation close to home, and things like that.
Making it showy, I suspect would make the effect preachy. Making it normal, I expect would lead people to feel times have changed.
It may sound small, but I bet they could make a big measurable effect with little effort. Every contribution helps.