Lead by example, let market forces play out, raising fuel prices will change behavior. Europe has had the equivalent of $6 gasoline, and slightly cheaper diesel for years. So KPL (MPG) is a selling factor, yet a small few still drive Land Rovers and Ferraris in Europe. Interesting no real Electric or H cars even with $6 gas for years. Go figure.
Behavior is also driven by cause and effect. As fast as the US could push away from carbon based transport, China and India will fill the gap, so in the end it will still get worse, not better.
So the hard sell is change your ways and things will still get worse or don't change your ways and things will get worse faster. For many, that isn't a great selling point. And we have seen time and again Government intervention in market forces doesn't work as planned.
Give people choices and educate them on the impacts of their carbon footprint, combine that with raising Oil prices, and the market will shift.
And if you have a wide open green lawn, plant some tress. We can do more than just slow down our CO2 emissions, we can help clean up the air with our actions too. CO2 isn't created, it is just stored (plants to oil) and liberated (oil to combustion). So liberate less and store more!