Sensitivity analysis in a life cycle assessment of an aged red wine production from Catalonia, Spain

Sustainability in agriculture and food processing is an issue with a clear growing interest; especially in products were consumers have particular awareness regarding its environmental profile. This is the case of wine industry depending on grape production, winemaking and bottling. Also viticulture and generally agricultural production is significantly affected by climate variations. The aim of this article is to determine the environmental load of an aged red wine from a winery in Catalonia, Spain, over its entire life cycle, including sensitivity analysis of the main parameters related to the cultivation, vinification and bottling. The life cycle assessment (LCA) methodology is used for the environmental analysis. In a first step, life cycle inventory (LCI) data were collected by questionnaires and interviews with the winemaker, all data are actual operating data and all the stages involved in the production have been taken into account (viticulture, vinification, bottling and the disposal subsystem). Data were then used to determine the environmental profile by a life cycle impact assessment using the ReCiPe method. Annual variability in environmental performance, stresses the importance of including timeline analysis in the wine sector. Because of that this study is accompanied with a sensitivity analysis carried out by a Monte Carlo simulation that takes into account the uncertainty and variability of the parameters used. In this manner, the results are presented with confidence intervals to provide a wider view of the environmental issues derived from the activities of the studied wine estate regardless of the eventualities of a specific harvesting year. Since the beverage packaging has an important influence in this case, a dataset for the production of green glass was adapted to reflect the actual recycling situation in Spain. Furthermore, a hypothetical variation of the glass-recycling rate in the glass production completes this article, as a key variable of sensitivity analysis, in order… in order to show the potential reduction of total greenhouse gas emissions. It was found that in almost all categories the production of the glass bottles has the highest environmental impact (10%-80% depending on the impact category) followed by the viticulture stage, i.e. the agricultural activities (17%-84% depending on the impact category). The vinification step, i.e. the winemaking itself, has an almost negligible effect on the overall load (1%-5%). The sensitivity analysis showed that the results do not differ by more than ±4% from the expected values except for the water depletion indicator. With the variation of the recycling rate, it could be shown that an increase in the rate from 60% to 85% allows for a reduction of 102gCO2eq. per bottle (-11.1%). The results show that glass production causes the highest environmental load. The key parameters that determine the impact are the recycling rate and the bottle weight. A glass container deposit legislation might be a promising way to enhance the glass recycling. Lightweight bottles and alternative packaging should also be considered.