You’ve ditched dairy, but which milk alternative is actually best for the environment?

Figure 1: Milk alternatives

With our current diets and production systems, feeding over 7 billion people is degrading terrestrial and aquatic ecosystems, depleting freshwater resources, triggering biodiversity loss and driving climate change. These impacts will increase globally over the next few decades due to population growth and income-dependent dietary shifts towards meat and dairy-based diets. This blog will focus on the environmental impact of different kinds of milks by reviewing life cycle assessment (LCA) studies. In general, LCA studies show that food products of animal origin have higher climate, freshwater and land use related impacts than vegetable products.

An Oxford study by Poore and Nemecek (2018) found that the environmental impacts of dairy milk exceeded the average impacts of all milk substitutes across greenhouse gas (GHG) emissions, eutrophication, acidification, water use and land use degradation. Methane from enteric fermentation, manure management and emissions from feed production are stated as the main contributors to the animal milk carbon footprint.

Figure 2: The environmental impact of one glass (200ml) of different milks

It is clear that dairy has the most negative environmental impacts of all the kinds of milks, but that is not to say that the milk alternatives do not have a dark side. For example, the Oxford study also found that almond and rice milk demanded 74 and 54 litres of water per glass to produce respectively, which is much greater than other milk alternatives. Furthermore, a Guardian article stated that because coconuts and soybeans (for coconut and soy milk) can be grown in tropical climates in developing countries, there has been a rise in rainforest deforestation and worker exploitation. Rainforest destruction is especially severe as it causes reduced evapotranspiration which can lead to more arid climates and warmer local temperatures. It also causes a reduction in carbon sequestration which can cause more rapid global warming. Oat milk is the clear winner on the sustainability scale according to both the Oxford study and the Guardian article. This milk requires less water and land use compared to dairy milk and as oats are grown in cooler climates, it is also not associated with rainforest destruction.

However, with all the facts considered, if you’ve switched from animal milk, you’ve already addressed the most pressing environmental problems that your milk habits were causing, so well done if you have ditched the dairy.