A Comparative LCA of Milk and Plant-based Alternatives

The global food system is at a crossroads for change, driven by increasing consumer demand for substitution of animal-based foods with plant-based foods. The dairy alternatives market, specifically, is projected to grow... [ view full abstract ]

The global food system is at a crossroads for change, driven by increasing consumer demand for substitution of animal-based foods with plant-based foods. The dairy alternatives market, specifically, is projected to grow globally from 8.2 billion in 2014 to 19.5 billion in 2020 with soymilk and almond milk expected to be the largest segments of the market. Almond milk is expected to be the fastest growing segment due to the growing trend for soy-free alternatives. Almond and soy milk have become popular alternatives for cow milk because of their health benefits. In addition, they are believed to have reduced environmental impacts, such as lower greenhouse gas emissions and fewer land requirements. However, production of almond and soy products requires irrigation processes that consume large quantities of water. As more than 80% of the world’s almond supply relies on California’s water and energy resources and with the ongoing drought in California, this presents a challenge for supplying adequate human nutrition in a sustainable manner. Although many life cycle assessment (LCA) studies have addressed the environmental impacts of cow milk, none have compared cow milk with almond and soy milk. This study is the first comparative life-cycle assessment of conventional dairy milk with emerging non-dairy milk alternatives. Research will be presented that examines the life-cycle differences in water footprint, embodied energy, and greenhouse gas emissions for cow milk, almond milk, and soy milk produced in California and Wisconsin along with the nutritional quality of each. The scope of the study is a cradle-to-grave assessment with the functional units of 1 liter of milk consumed and nutritional indicator units of grams of protein and kcal of food energy. This study will also examine a method for addressing water scarcity impacts in LCA to account for regional differences in the water used for agricultural production of soy, almond and cow milk. The results of the study will provide guidance to consumers to make environmentally responsible choices in their food consumption and to assist policymakers when designing policy promoting sustainable food systems