The concept of natural capital emerged more than three decades ago; it is defined as “a stock of natural resources (i.e., ecosystems) that yield a flow of goods and services (i.e., ecosystem services).” We present as well a definition of ecosystem services: “the benefits that people obtain from ecosystems”; as we describe, these can be economically valued through a wide variety of methods, each one depending on the service that needs to be valued. Economic valuation has been criticized, perhaps because of a misunderstanding of the concept of value, which we also define here. We also present some difficulties in conducting these studies. We finish this chapter with a reflection of the approach of natural capital within sustainable development.

JEL Classifications: Q00, Q57