The Environmental Cost of Dairy and Plant-Based Milks

Plant-based milk alternatives have become a staple in coffee shops and grocery stores worldwide. From soy and almond to oat, pea, coconut, and rice milk, these non-dairy options are increasingly popular not just for dietary reasons, but also for their perceived environmental benefits.

Marketed as more climate- and eco-friendly than traditional dairy products—such as cow, goat, buffalo, or sheep milk—these alternatives are reshaping how we think about milk consumption.

The food industry plays a substantial role in contributing to greenhouse gas (GHG) emissions. As the global community aims to limit temperature rise to 1.5 °C and meet sustainability objectives, the environmental impact of food products, including milk, is increasingly influencing consumer choices.

Several factors are considered when evaluating the environmental impacts of various animal- and plant-based milk products. These include the GHG emissions generated during their production. For example, the production of cow’s milk involves raising the cows, growing their feed, packaging, shipping, and using freshwater, land, fertilisers, pesticides, and antibiotics.

The WRI graph below illustrates the environmental impact of various milk products. This data is derived from the 2023 study titled “Dairy and Plant-Based Milks: Implications for Nutrition and Planetary Health.”

The World Resources Institute (WRI) analysis indicates that plant-based milks—like coconut, pea, almond, oat, and soy—produce, on average, 33% less greenhouse gas (GHG) emissions than cow’s milk. Some, such as coconut and pea milk, also use less water, but most of these non-dairy alternatives fall short in protein content compared to cow’s milk.

Pea milk is comparable in protein to cow’s, with oat milk being a close second. Coconut milk has the lowest GHG emissions and water usage, but also the lowest protein content. Almond milk’s water consumption is similar to that of cow’s milk, depending on the growing conditions. The WRI notes that when selecting a milk option, individuals also consider factors like taste, dietary restrictions, and availability when choosing milk.

The BBC article compares the climate impacts of dairy milk and plant-based alternatives, citing a 2018 study titled “Reducing Food’s Environmental Impacts through Producers and Consumers.” On average, dairy milk has significantly higher greenhouse gas (GHG) emissions and land use than plant-based milks, such as those made from rice, soy, oat, and almond.

For example, producing a glass of dairy milk daily for a year requires 650 square metres (7,000 square feet) of land, more than ten times that of oat milk. Almond milk needs 74 litres of freshwater per glass, while rice milk requires 54 litres, although dairy milk still consumes more freshwater overall. Moreover, the carbon footprint of dairy milk can vary depending on its production location due to factors such as transportation, packaging, processing, and deforestation.

The article includes a graph below showing the carbon footprint of dairy milk based on the cows’ location.

A study titled “Environmental Impact of Animal Milk vs. Plant-Based Milk: Critical Review,” published in April 2024, examined the environmental impacts of animal-based milk (ABM) from cows, buffalo, goats, and sheep, as well as plant-based milk (PBM) options like almond, oat, soy, pea, and coconut.

The researchers analysed 70 life cycle assessment (LCA) studies to achieve two main goals: to develop a universal framework for comparing animal and plant-based milk, and to standardise the eco-friendly comparison of different milk types using various eco-indicators based on the aggregated results.

The findings revealed that cow milk has the lowest global warming potential (GWP) among animal milks, measuring 1.29 kg CO2 per kg. In contrast, coconut milk emerged as the best option among plant-based milks, with only 0.257 kg CO2 per kg.

Additionally, the study identifies major environmental problem areas, or hotspots, affecting both types of milk. It also offers suggestions for which processes should be prioritised for improvement to enhance the environmental sustainability of both dairy and non-dairy milk systems.

Hotspots for dairy milk

Enteric fermentation is the leading contributor to greenhouse gas (GHG) emissions in milk production, accounting for up to 69% in cow’s milk, 44% in buffalo milk, 33% in goat milk, and 78% in sheep milk.

Feed production, associated with forage and silage cultivation, is the second largest contributor. Manure management also contributes significantly to methane (CH4) and nitrous oxide (N2O) emissions, with combined estimates from enteric fermentation and manure emissions ranging from 57% to 76%.

Hotspots for plant-based milk

Plant-based milk (PBM) production differs from dairy systems and involves various industrial processes. Major GHG hotspots include processing steps like dehulling, grinding, pasteurisation, and sterilisation, as well as the production of additives.

Estimated GHG emissions vary by product: almond milk (14.4% to 61.7%), oat milk (26.8% to 45%), pea milk (63.1% to 72.8%), and soy milk (4.8% to 66%). Other hotspots include packaging, particularly plastic bottles, as well as the impacts of farming and transportation. Notably, almond milk production utilises 95% of its land and water for freshwater consumption during cultivation.

A comparison of plant-based and animal-based milk shows that plant-based options are generally more sustainable in terms of global warming potential. However, animal-based milk has advantages over plant-based milk in terms of water footprint and energy use when water scarcity is considered.

The study suggests that GHG mitigation for dairy milk should focus on reducing enteric fermentation, improving manure management, and optimising feeding strategies. In contrast, non-dairy milk mitigation should focus on emissions from processing, packaging, and transportation.

As consumers become more environmentally conscious, the choice between animal-based and plant-based milk is no longer just about taste or nutrition—it’s about sustainability.

While no milk alternative is perfect, plant-based options generally offer a lower carbon footprint and reduced impact on land use and water consumption. However, understanding the full life cycle of these products—from farming to processing to packaging—is essential for making truly informed decisions.

Ultimately, the path to a more sustainable food system doesn’t hinge on a single solution but on a series of mindful choices. By considering the environmental trade-offs of each milk type and supporting innovation in sustainable agriculture and production, we can all contribute to a future where what we pour into our glass aligns more closely with the health of our planet.