Wood forest resource consumption impact assessment based on a scarcity index accounting for wood functionality and substitutability (WoodSI)

Abstract

For society to continue to use forest resources in a sustainable manner, we need to be concerned about how they are consumed now and about the future needs. Life cycle assessment (LCA) is a robust tool, scientifically based and possible to be adapted to the quantification of multiple environmental issues in a systemic way. Deforestation and forest degradation continue to take place at threatening rates by the wood resource use and by land use issues (agricultural production, mineral extraction, and human settlement). However, currently, the depletion of forest resources by wood resource use is not adequately considered in LCA. Little progress was done recently in biotic resource depletion impact assessment, and no method can be recommended without considerable restrictions. It is therefore necessary to better characterize the depletion of forest resources in LCA. The present study aims to develop a characterization model that assesses the potential impacts generated by the loss of wood forest resource availability caused by consumption through a functional approach. Considering the operationalization model for biotic resources proposed by Heijungs et al. (1992) and the wood functionality through substitution index proposed by Lima et al. (2018a), a characterization model was developed based on a scarcity index accounting for wood functionality and substitutability (WoodSI). This characterization model considers the consumption, the renewability of the resource, the current stock, and the capacity to substitute the resource (at different wood functions such as sawn wood, wood pulp, wood based panels, wood charcoal, and fire wood) in each country in its calculations. WoodSI is a mid-point model. Three scenarios (less conservative, more conservative, and medium) were analyzed for practitioner choice. Characterization factors were calculated for 193 countries, 60% of which have some level of scarcity and share only 20% of the World forest. The wood functions (or uses) with the highest level of potential World shortage were charcoal and wood pulp production. In general, countries with large forest area or high growth rates do not have any scarcity index detected by the method (e.g., Brazil, Russia, and Australia), but in countries with high consumption rate (such as USA, China) or smaller forests areas, some scarcity was already detected. The WoodSI model contributes to the progress of the natural resource depletion impact category by deepening the discussion in its cause-effect chain and developing an impact model. The wood renewability considers distinct forest classification and its main representative’s species. The instrumentality value is addressed by considering the resource usefulness through its functionality and distribution at country level. It has good data availability since the data obtained are from a public, open database, and values may be updated every 5 years.