Circular wood use can accelerate global decarbonisation but requires cross-sectoral coordination

The forestry value chain plays a crucial role in the circular economy (CE) as a significant source of renewable biomaterial, offering multifaceted climate-change mitigation benefits through carbon sequestration and avoided emissions from substituting fossil-fuel-derived products. Global primary processed wood product consumption is projected to increase substantially by 2050, but current value chains are inefficient and unsustainable under the prevailing linear economy model. There's significant potential to enhance the sustainability of forestry value chains and their contribution to net-zero greenhouse gas (GHG) emissions, aligning with Paris Agreement goals. Current decarbonization and CE policies often have a narrow sectoral focus, lacking cross-sectoral integration and neglecting the circular use and recycling of wood within a cohesive decarbonization strategy. This study employs prospective lifecycle assessment (LCA) with broad boundaries to quantify the additional mitigation potential of implementing CE principles in the forestry value chain, providing crucial evidence for systemic change needed for rapid and sustained climate-change mitigation. Transitioning to a CE presents a complex challenge requiring substantial socio-economic structural changes and industrial reorganization. To optimize climate-change mitigation, the forestry value chain needs to function as a societal change system (SCS) with shared goals and principles guiding coherent action. A high-functioning SCS needs to effectively execute seven critical change functions: system visioning, system organizing, resourcing, learning, measuring, advocating, and prototyping. This study addresses two key evidence gaps to inform effective policy and industry actions for net-zero GHG emissions: (1) identifying wood-use strategies significantly increasing climate-change mitigation through dynamic, consequential LCA; and (2) proposing key system change enablers by interviewing forestry value-chain actors about perceived barriers to circularity and analyzing responses against a societal change matrix.

The authors reference several studies highlighting the importance of the circular economy and its applications in various contexts, including sustainable businesses and the concept's limitations. They cite existing literature on the potential for climate-change mitigation through afforestation and the use of renewable materials, while noting the current lack of cross-sectoral integration in sustainability policies. The limitations of linear economy models in meeting future wood demand are discussed, along with existing work that has catalogued external factors (political, economic, sociological, technological, legal, and environmental) impacting actions at an organizational level within the forestry value chain. However, they highlight the absence of an analysis of the forestry value chain as a societal change system (SCS), leading to a gap in understanding the systemic barriers hindering the implementation of circular economy principles. The authors also reference methods for conducting dynamic consequential LCA, emphasizing the need for high-resolution data to accurately assess the climate-change mitigation impact of different wood-use strategies.

This study employed a mixed-methods approach combining dynamic consequential LCA and SCS analysis. The LCA assessed the climate-change mitigation impact of four UK softwood use scenarios (business-as-usual, enhanced cascading, enhanced circular, and cascading & circular) from 2022 to 2050. The LCA accounted for progressive industrial decarbonization and considered a range of emissions sources (Scopes 1-4). The SCS analysis involved in-depth semi-structured interviews with 17 individuals from diverse organizations across the UK forestry value chain. Interview data were analyzed using a societal change matrix to identify barriers to circularity and decarbonization across seven change functions: system visioning, system organizing, resourcing, learning, measuring, advocating, and prototyping. The LCA used high-resolution data from a detailed case study of the UK domestic forestry value chain, utilizing consequential LCA to assess climate-change mitigation impact, measured as 100-yr global warming potential (GWP) in CO₂e emissions. Four wood-use scenarios were assessed: business-as-usual ('BAU'), enhanced cascading, enhanced circular (recycling medium-density fibreboard (MDF)), and cascading & circular. The analysis included the GWP contributions of different value-chain components (Scopes 1–4) in 2035 and the dynamic annual net GWP impacts from 2022–2050. An afforestation scenario was also included for comparison. The SCS analysis involved semi-structured interviews with 17 individuals across the UK forestry value chain, analyzing responses against a societal change matrix to identify barriers and enablers of change. Directed content analysis was used to categorize barriers under the seven change functions mentioned above, with barriers further categorized by sub-sectors and related systems (technology, policy, producers, consumers, and finance).

The LCA showed that circular and cascading wood use strategies substantially enhance climate-change mitigation compared to business-as-usual. The circular approach of recycling MDF delivered 75% more cumulative climate-change mitigation by 2050 in the UK example. In the year 2035, the cascading scenario reduced Scope 1-3 emissions by 35% compared to BAU, while the circular and cascading & circular scenarios achieved 85% and 87% larger net GWP reductions than BAU, respectively. The largest GWP reduction was achieved by the combined cascading & circular scenario. The benefits of circular wood use are robust to industrial decarbonization, as the dominant biogenic carbon storage credits (change in HWP C storage and avoided emissions-reduced harvest) are less affected by decreasing avoided emission factors from other industrial decarbonization efforts. Early implementation of circular and cascading wood use maximizes the speed and magnitude of cumulative GWP reduction. A net-zero (Scopes 1-3) GWP forestry value chain by 2050 is only achievable with circular wood use. Circular wood use creates a carbon sink, and combining circular wood use with afforestation can achieve significant GWP reductions. The SCS analysis revealed numerous barriers across all seven change functions, hindering the transition to a circular economy in the forestry value chain. These barriers include the lack of a shared vision for the role of forestry in a net-zero circular economy, limited willingness to collaborate across the value chain, insufficient resources, slow knowledge sharing, inadequate measuring of progress, limited advocacy for change, and conservatism towards innovation.

The findings highlight the significant climate-change mitigation potential of transitioning to a more circular forestry value chain. The substantial improvements in GWP reduction from circular and cascading approaches, especially when compared to business-as-usual and even cascading alone, demonstrate the effectiveness of prioritizing circularity in wood use. The resilience of these benefits to industrial decarbonization emphasizes the long-term sustainability of this approach. The synergy between circular wood use and afforestation further strengthens the case for integrating these strategies into national net-zero strategies. However, the identified systemic barriers reveal the challenges involved in implementing such a transition. Overcoming these barriers requires a multi-faceted approach involving international collaboration to establish a shared vision, enhanced collaboration within the value chain, increased resources, improved knowledge sharing, the development of effective measuring tools, active advocacy for change, and fostering a culture of innovation.

This study provides strong evidence supporting the significant climate-change mitigation potential of circular wood use within forestry value chains. The combined approach of cascading and circular wood use offers substantial immediate and sustained decarbonization benefits, exceeding the impact of linear models and complementing afforestation efforts. However, overcoming systemic barriers requires a concerted effort involving international collaboration, policy changes, increased investment, and a shift towards a more collaborative and innovative culture within the forestry sector. Future research could explore the potential of yet-unexplored circular initiatives and the implications of scaling up these strategies globally.

The study focuses on the UK forestry value chain, limiting the generalizability of findings to other contexts with varying wood production, processing practices, and policies. The LCA models rely on existing data and may not fully capture the complexities and uncertainties of future technological advancements or market dynamics. The SCS analysis is based on the perspectives of a specific group of stakeholders, and the findings may not fully represent the diversity of views and experiences across the entire forestry value chain. The afforestation scenario used for comparison is simplified and may not fully reflect the range of possible afforestation strategies and their associated impacts. While the authors aimed for a conservative approach regarding the conclusions, there could still be some uncertainties about the precision of the results due to the complexities involved in calculating the contribution of avoided emissions, particularly related to harvest reduction and product substitution.