Colorado

When I moved to Uruguay, once-used plastic grocery bags (mostly) were everywhere around the city blowing in the wind, hanging from trees, piling up along the walls, dancing in the curious whirls caused by buildings.

A law was passed requiring nearly all stores to charge 4 pesos per bag; the neighborhood and environmental problem went away almost overnight. Seems that a bit of a personal stake (about 10 cents US- but more like 50 in relation to low wages) changed behavior.
People have backpacks, cloth sacks, reuse their 4-peso plastic or, ubiquitous here, have a small-wheeled frame with fabric sack for shopping.

I get to see a much cleaner parque below my balcony.