Investigation of Circular Economy from Sustainability Point of View Using a Global Integrated Model

Research in the field of the circular economy is mainly focused on economic benefits [1,2]. Hence, its holistic assessment from a sustainability point of view, specifically addressing the ecological implications, is essential. This research gap is addressed here.

An integrated global socio-economic-ecological model originally developed by the US-EPA is selected for this work [3,4]. This is based on a food web model with multiple trophic levels, and human-essential industries including one producing consumer goods. The economic dimension is integrated using the macro-economic price setting model.

Simulations are carried out for different levels of consumption (2 to 10 times) over a period of 200 years. The industrial sector depends on agriculture for raw materials. The collapse of the agricultural sector because of over-exploitation is observed. After incorporating the circular economy in the form of an industry that recirculates the used consumer goods, with a constant circulation of 17%, this collapse is delayed by at least 20 years.

The maximum level of circulation, the delay before adoption and the rate of adoption define the pathways for the adoption of the circular economy. 810 scenarios, 90 pathways with 9 consumption levels, are simulated. Aggressive adoption of the circular economy delayed the collapse of the agricultural sector further, in several cases leading to sustainable behaviour throughout the simulation horizon of 200 years. However, for very aggressive adoption pathways, the open access grassland (which competes with the agricultural sector for nutrients) collapses because of high agricultural demand. The set of solutions that provides sustainable pathways form a sustainability corridor which becomes narrower with increasing consumption, thus reducing the operating space for the policymakers.

This work, thus, establishes the benefits of incorporation of the circular economy from sustainability point view and underlines the importance of the dynamics of adoption of the circular economy.