ABSTRACT
The main theme in environmental economics is that nature is capital. Sustaining a steady stock of environmental capital (KN) is a necessary condition for economic sustainability. This is because KN acts as both a source and a sink for the economy. It is a source for the basic resources the economy needs and a sink for the wastes that the economy generates. When and where the contributions of KN to the economy are disregarded, the ability to produce and enjoy the goods and services generated by the economy are undermined.
