Transforming the bio-based sector towards a circular economy - What can we learn from wood cascading?

The circular economy has become the focus of a recent major EU policy program, which aims at the transformation towards environmentally sustainable modes of production and consumption. This has moved parts of the forest and related bio-based industries to envision their operations in terms of a circular economy. However, the meaning and implementation pathways of the concept often remain vague and ambiguous. At the same time, bio-based industries have a long history of discussing and partly realizing wood cascading. This concept strongly overlaps with circular economy ideas as it describes activities to increase the efficiency of biomass utilization. This article takes stock of wood cascading research and identifies major influencing factors for its realization to provide a comprehensive knowledge base for discussions about the circular economy in forest and related bio-based industries. Based on a review of peer-reviewed literature, we find substantial knowledge available on the factors influencing the realization of wood cascading. These factors largely resemble what is currently being discussed as barriers and enablers of circular economy. Some crucial influencing factors, like policy limitations, are frequently highlighted but remain barely investigated. In addition, the various influencing factors are interdependent, making a conclusive assessment of the environmental impacts of a change to certain cascading activities extremely challenging. The challenges of quantitative assessments combined with the substantial knowledge gaps on political and socio-economic factors result in certain assumptions and political recommendations that hardly appear to be based on empirical evidence. We therefore suggest scrutinizing these assumptions and filling knowledge gaps, especially related to product design, potentials and limitations of long-lived products, and avoidance of waste generation