Herman Daly, ecological economist, in an interview with Seed Magazine:

Elementary economic theory describes something called a circular flow diagram: Firms supply goods and services to households, which in turn supply labor and capital factors of production back to the firms. This flow goes around and around, and money flows in the opposite direction to pay for it.

The way it’s usually depicted is as a closed circulatory system. What’s imagined is the economy’s digestive system: the input of low-entropy raw materials from the environment and the expulsion of high-entropy waste products back into the environment. A fundamental assumption of those who treat the economy like a totally circular exchange is that the environment is infinite relative to us, that natural resources and space absorb our waste are not scarce. The assumption is no longer valid.

. . . we’re faced with two impossibilities. On one hand, it’s politically impossible to stop growth. On the other hand, it’s biophysically impossible to continue it ad infinitum.