The answer is incentive and positive reinforcement.
Ppl have shown to want to do good things, but it's hard to do good things when all the "good things" cost more or is harder to do than the alternative.
Many studies have proven this.
For example, when trash cans are plentiful in a city or a park ppl, will typically carry their garbage a little longer to dump it. If not they will just toss it anywhere.
If you see recycling bins in a food court ppl are more likely to recycle their recyclables rather than just dump it in the trash.
When their are financial incentives to use your electricity or water at certain times of the day ppl will hold off and wait....to save money.
Lots of ppl would love to have solar panels, electric cars, etc. But that shyt is just too expensive or inconvenient.
It's also about reframing the message. It needs to be personal, and it needs to apply to them right now. When they are told that in 1000 years the temperature will rise 3 degrees and ny will be Atlantis and shyt....no one cares, because no one will be around. There is no emotional attachment to it.