Transition to plant-based diets is increasingly considered a crucial step in mitigating the climate impact of food systems. Plant-based milk alternatives is the leading category within plant-based foods, with a rapidly growing market globally. Yellow peas (Pisum sativum) are emerging as a promising raw material in the growing plant-based food sector, valued for their nutritional and environmental benefits. In Sweden, efforts are underway to establish a domestic legume supply chain to support their wider use. Given these ongoing developments, this study evaluates the life cycle of yellow pea milk alternative produced entirely in Sweden, employing cultivation data from Västmanland County  in central  Sweden. Life Cycle Assessment was conducted using the ReCiPe 2016 method from a hierarchist (H) perspective, covering midpoint impact categories with a particular focus on climate change, eutrophication, acidification, and water use. 

The total global warming potential for 1 litre of pea-based milk alternative was found to be 0.399 kg CO₂-eq, with the largest contributions to be the production of other ingredients (0.150 kg CO₂-eq), yellow pea cultivation (0.111 kg CO₂-eq), and the packaging (0.078 kg CO₂-eq) phase. Water consumption was estimated at 0.00505 m³ per litre, primarily driven by the milk alternative production phase and packaging. Cultivation of yellow peas emerged as the dominant contributor to both marine and freshwater eutrophication impacts, while the production of other ingredients significantly influenced all categories. 

The results show that the environmental performance of pea-based milk alternative is sensitive to both the type and quantity of ingredients used. In addition, while aggregated data from the Agri-footprint 6 database closely aligns with data from the referenced farmer, both Life Cycle Assessment practitioners and database developers should consider integrating crop rotation and a systems perspective into their assessments, especially for legumes like peas, to better capture their full environmental benefits. Finally, the comparison between pea-based milk alternative and oat-based milk alternative illustrates the challenges in making environmental claims due to variations in ingredients, processing methods, data sources, and product types. Despite these complexities, the two products studied showed similar GWP values (0.250 vs. 0.266 kg CO₂-eq./L for pea- and oat-based milk alternative, respectively) when excluding additional ingredients. However, the oatbased milk alternative’s naturally derived sweetness may mean its impact is slightly underestimated. While pea-based milk alternative had a more intensive processing phase, this was not weighed against its potentially higher protein content.