In this article we explore the quantitative challenges posed by the intended circular biobased economy. To do this, we present the relative sizes, in terms of mass and energy, of the agro-food and fossil production system, and the interrelations in the system of transformation to food, feed, materials, and energy. We deduce that the flows in the fossil system are of a comparable magnitude to the agricultural / biomass production in terms of mass and energy. This implies that replacing a significant fraction of fossil-derived products by biobased products will be a huge challenge. Solving this challenge will require both efficiency improvements and circular innovations. The analysis reveals major inefficiencies in the current system. In terms of mass, the pathways from agricultural production to food seem quite inefficient, on average less than 10%. This suggests space for efficiency improvement. The relatively low efficiency of livestock production confirms the relevance of diet change. Likewise, enhanced utilization of side streams appears significant. However, we show that in the current system of linear chains, such solutions are insufficient to provide an alternative to the current volume of fossil use. We argue that, next to biobased solutions, multifunctional use and recycling will be essential if we want to maintain current living standards and reduce dependence on fossil feedstock. We reflect on this consideration, and define four different cycles in the combined biomass / fossil system. These circles may be optimized and extended to improve the circularity of our carbon-based production systems and to fight climate change. (c) The Authors. Biofuels, Bioproducts and Biorefining published by Society of Chemical Industry and John Wiley & Sons, Ltd.
