In this article, the authors propose an impact assessment method for life cycle assessment (LCA) that adheres to established LCA principles for land use-related impact assessment, bridges current research gaps and addresses the requirements of different stakeholders for a methodological framework. The conservation of biodiversity is a priority for humanity, as expressed in the framework of the Sustainable Development Goals (SDGs). Addressing biodiversity across value chains is a key challenge for enabling sustainable production pathways. Life cycle assessment is a standardised approach to assess and compare environmental impacts of products along their value chains. The impact assessment method presented in this article allows the quantification of the impact of land-using production processes on biodiversity for several broad land use classes. It provides a calculation framework with degrees of customisation (e.g., to take into account regional conservation priorities), but also offers a default valuation of biodiversity based on naturalness. The applicability of the method is demonstrated through an example of a consumer product. The main strength of the approach is that it yields highly aggregated information on the biodiversity impacts of products, enabling biodiversity-conscious decisions about raw materials, production routes and end user products.

The global carbon neutrality challenge places a spotlight on forests as carbon sinks. However, greenhouse gas (GHG) balances of wood for material and energy use often reveal GHG emission savings in comparison with a non-wood reference. Is it thus better to increase wood production and use, or to conserve and expand the carbon stock in forests? GHG balances of wood products mostly ignore the dynamics of carbon storage in forests, which can be expressed as the carbon storage balance in forests (CSBF). For Germany, a CSBF of 0.25 to 1.15 t CO₂-eq. m⁻³ wood can be assumed. When the CSBF is integrated into the GHG balance, GHG mitigation substantially deteriorates and wood products may even turn into a GHG source, e.g., in the case of energy wood. In such cases, building up forest carbon stocks would be the better option. We conclude that it is vital to include the CSBF in GHG balances of wood products to assess the impacts of wood extraction from forests. Only then can GHG balances provide political decision makers and stakeholders in the wood sector with a complete picture of GHG emissions.

Biomass-based fuels are frequently considered a Greenhouse Gas (GHG) emission reduction option. However, the aspect of foregone emission reduction which is related to alternative options such as renaturation is neglected in most cases. This study outlines carbon opportunity costs (COC) for crop-based biofuels used in Germany. In 2020, energy crops for 44 peta joules of biofuels were cultivated on arable land in Germany. The area required for this amounts to 0.461 million hectares, after deducting the area for co-products such as rapeseed meal. A large part of the biofuels used in Germany is imported and occupies extensive areas, particularly in Asia, mainly through the cultivation of oil palms. In total, the biofuels consumed in Germany occupy 1.23 million hectares worldwide, which corresponds to more than 10% of Germany's arable land. According to official data, the greenhouse gas emissions saved by using biofuels based on crops instead of fossil fuels amounted to 9.2 million t CO₂ -eq. in 2020. If this saving were renounced and instead natural vegetation were allowed to grow on the land occupied for biofuels, an average annual carbon sequestration of over 16 million t CO₂ would be possible as a result. These are the COC of biofuel production, and they are significantly higher than the emission reductions from replacing fossil fuels.