A basic feature of the utility function (demand curve) is the law of diminishing marginal utility. That is, as a person consumes an item or a product, the satisfaction or utility that they derive from the product wanes as they consume more and more of that product. In other words, the price a person is willing to pay (or the demand) for that product decreases with consumption. However, our demand for some environmental goods (e.g., clean air/water) does not wane with quantity.

Does this mean utility function theory does not apply to environmental goods? If it applies, how would you use the utility function theory to explain the supply of and demand for clean air/water?