Environmental & Resource Economics

What is the economic intuition behind the following statement, in your answer use all the topics and definitions learned in class. Let's say each household generates one kilo of garbage. And one kilo of garbage generates 500 grams of recyclable material. So, a thousand homes generate 500 kilos of material that could be recycled. That's 500 kilos less of material that would pollute the rivers, the lagoons that won't clog the sewers or be buried here in the landfill doing such great harm to nature and the environment. What people can recycle and what they can compost is of great importance. But people say that it is just one can, what difference does it make? One can is of great importance because 99 is not a 100 and that single can will make the difference.