Here’s a journal article with some discussion of the Environmental Kuznets Curve, which is the idea that a developing country’s environment will slowly degrade, then improve again. Having breathed and drank in a variety of countries, it is pretty clear to me that the concept applies to air and water pollution, but not to overall ecological footprint, wildlife habitat, or long-term stability of our atmosphere and oceans. I suspect that this is because air and water pollution are things people can understand – they affect health, safety, and property values in pretty obvious ways. Over time, economic development starts giving people some money, education, and leisure time, and they become more politically active, generating pressure to clean up the immediate human environment. But people don’t understand or don’t care about the long-term ecological issues as much, so the political pressure does not develop.

The main purpose of this paper is to present a theoretical model incorporating the concept of circular economic activities. We construct a circular economy model with two types of economic resources, namely, a polluting input and a recyclable input. Overall, our results indicate that the factors affecting economic growth include the marginal product of the recyclable input, the recycling ratio, the cost of using the environmentally polluting input and the level of pollution arising from the employment of the polluting input. Our analysis also shows that, contrary to the Environmental Kuznets Curve (EKC), environmental quality cannot be maintained or improved via economic growth. Instead, the improvement in environmental quality, as measured by a reduction in pollution, can only be achieved by an increase in the environmental self-renewal rate or the recycling ratio.