Climate effects of post-use wood materials from the building sector in a system perspective

This study investigates the climate change effects in terms of greenhouse gas emissions and radiative forcing resulting from different pathways of processing wood materials when they reach the end-of-life stage. The shares of combustion, landfill, recycling, and reuse, which vary with the pathways of post-use wood, influence the material and energy production systems. The dynamics of CO₂ and CH₄ emissions, together with the cumulative radiative forcing of each pathway, are evaluated from various regional system perspectives. The results show that the choice of a treatment pathway for post-use wood could strongly influence the profile of greenhouse gas emissions and, consequently, the global warming potential. Taking into account the situation of the reference material and energy production systems, the post-use wood can have unfavorable consequences for the climate, as in the case when the material and energy production systems are based on the low-carbon energy of natural gas. However, from the perspective where the treatment of post-use wood influences the quantity of forest biomass on the forest floor, the increased share of reuse and recycling contributes positively to the climate change mitigation, but only during the early stage. Under such a context, options relying on carbon capture and storage to handle biogenic CO₂ emissions at energy conversion facilities could cause a cooling effect on the Earth's atmosphere.