classification of garbage

I was  surprised at my friend's classification of garbage when I saw the scene my friend throw away garbage. He threw garbage away without classification. In my hometown Nagano, we must classify garbage when we throw away garbage. For example, combustible and incombustible, can, glass, and so on. So, I was very surprised at my friends action. In my opinion,wakayama people doesn't classify garbage. I think classification is very good for environment. If we throw away plastic production, many CO2 are emitted. So, I think people should classify garbage more, and the administrations should force people to classify garbage strictly. Classification is very small thing, but it's very important action.