Modelling the influence of climate change on characterization factors for copper terrestrial ecotoxicity

Abstract

The use of copper-based preparations is a long-standing practice in viticulture to control vine fungal diseases, which has led to high copper concentrations in vineyard soils and impacts on off-target terrestrial organisms. Under projected climate change, some of the mechanisms and properties of soils that influence the extent of metals ecotoxicity impacts are projected to be altered, namely soil erosion, rainfall, temperature, and organic carbon content. In this context, and within the framework of life cycle assessment, this study aims to simulate the influence of projected changes in soil organic carbon, soil erosion, and rainfall on characterization factors (CFs) for copper terrestrial ecotoxicity across non-calcareous European vineyard soils. We employed empirical regression models to account for metal speciation and bioavailability as determined by soil characteristics. CFs were computed for a current scenario and mid-term future scenarios by 2050 determined across three Representative Concentration Pathways (RCP2.6, RCP4.5, and RCP8.5). Although future scenarios suggest that CFs may either increase or decrease, CFs are projected to increase for a larger share of the European vineyard surface, which may lead to higher terrestrial ecotoxicity impacts. The RCP4.5 scenario projects the highest increases in CFs, with a 27% rise in the median CF in comparison with the current scenario. Whereas the RCP8.5 and RCP2.6 scenarios project a 19% and 14% increase in median CFs, respectively. The changes in CFs were determined principally by the changes in copper bioavailability driven by projected changes in soil organic carbon. However, the spatial variability of CFs was larger than the temporal variation, with a variation of roughly 2 orders of magnitude across the analyzed scenarios. This study highlights the relevance of integrating spatial differentiation and the influence of projected climate change in the characterization modelling of copper terrestrial ecotoxicity.