Life Cycle Assessment modeling of milk production in Iran

•Iranian milk production was environmentally assessed with a life cycle approach.•Five impact categories are assessed.•The highest potential for environmental impacts of production revealed for acidification.•Environmental index (EcoX) and resources depletion index (RDI) were obtained 0.61 and 0.04, respectively.•Implementation of animal feed management programs and use of biogas systems have been proposed.

Livestock units are known as one of the most influential sectors in the environment pollution. Therefore, the aim of this study was to investigate the environmental impacts of milk production in Guilan province of Iran through Life Cycle Assessment (LCA) methodology. The primary data were collected from 45 units of milk production through a field survey with the help of a structured questionnaire. The reliability was assessed using Cronbach’s alpha coefficient and was estimated an acceptable value of 0.91. The consumption of resources and emissions were allocated to a functional unit (FU) of one ton of milk. Impacts of emissions in five impact categories of global warming, acidification, eutrophication, photochemical oxidation and depletion of resources were investigated. The results showed that the characterization index for these impact categories were 1831 kg CO2 eq, 7.97 kg SO2 eq, 3.42 kg PO4−3 eq, 0.21 kg C2H4 eq and 838.39 MJ, respectively. Final indices for these impact categories were calculated as 0.24, 0.28, 0.076, 0.017 and 0.046, respectively. Environmental index (EcoX) and resources depletion index (RDI) were obtained 0.61 and 0.04, respectively. In this study, the highest potential for environmental impacts of production revealed for acidification and followed by global warming impact category.