Robust modeling of material flows to end-uses under uncertainty: UK wood flows and material efficiency opportunities

In this study we quantify wood flows from raw materials to end-uses for the United Kingdom in a robust way using a new material flow analysis (MFA) model with uncertainty. This is important to identify opportunities for efficiency given constraints on wood supply. We have developed a new "ProbPACTOT" MFA model which introduces a systematic method to handle mixed units during reconciliation and uncertainty in data observations, conversion factors, and process recipes. This makes it possible to track material flows all the way to end-uses, which is otherwise difficult because the diverse materials, data types, and units used to quantify end-products are hard to integrate into standard allocation-based MFA models. We apply the model for the case of wood in the United Kingdom by defining 56 process recipes and reconciling 117 data observations from various sources. The results quantify upstream production and trade flows, through to 19 specific end-uses of wood fibers. We use this to show the potential scale of savings by enhancing material efficiency; for example, if pallets were used 25% more intensively, 0.49 +/-$\pm$0.2 Mm3${\rm M}\mathrm{m<^>3}$ of wood fibers could be saved, corresponding to 4%-7% of the total soft sawnwood consumption of the United Kingdom. Judging the scale of opportunities for wood material efficiency in the United Kingdom is important domestically, and has global significance as the United Kingdom is the second largest net importer of wood products in the world. Moreover, this study proposes an important advancement in MFA giving a structure for modeling uncertain material flows up to end-uses, applicable to any material. This article met the requirements for a gold-gold JIE data openness badge described at .