Pollution is not treated separately here, because it is simply raw materials with the opposite sign convention: Pollution is the consumption of the raw materials known as "clean air," "available land," "clean water," etc. And those raw materials usually fall into one of the categories above.

Although it may be necessary to break each of the preceding distinctions further down: "Clean air," for example, can mean air without sulfuric acid (which is renewable - sulfuric acid washes out) or air without greenhouse gas pollutants (which is largely consumable).

- Jake

Friends come and go. Enemies accumulate.