What change in behavior did you observe? What made the difference?
People seem to be more likely to pick up after their dogs than they did ten years ago. I would guess that social pressure has a lot to do with that. Also, greater availability of bag dispensers in neighborhood parks. I don't get the sense that people are more aware of the environmental problems caused by dog waste. That seems about the same as before, but the behavior has changed.
I've noticed an increase in hand dryers or single portioned serrated paper towels in more bathrooms which completely removes or at least reduces the paper waste being generated when people wash their hands. The change seems to be brought about by companies or organizations wanting to reduce costs within their businesses. The environmental concern is 2nd to the economic value i think.
I have observed behavior change in relation to people installing more energy efficient equipment when they realize there is an incentive (normally financial) to implementing a change. Also, the process to receive the incentive, which is normally filling out a rebate form, needs to be simple and quick to complete, otherwise people will not even bother. Where I work, we have recently changed how we advertise rebate programs and the accessibility of the forms and have seen a marked increase of forms submitted.
I noticed that my mom started to believe her social media friends regarding the benefits of local/organic farming. This transition happened long after I moved out of her house. While still living with her, I would often talk about the need to make smart consumer choices, including local/organic foods (which often were more expensive). Because I was a 'young, naïve child' my ideas were quickly dismissed. Hearing the same information, from a different source made a huge difference.