From oat lattes to soy cappuccinos, Australians are increasingly diversifying their milk choices. While 96% of Australians still consume dairy milk, a significant 42% are now opting for plant-based alternatives, with some households stocking multiple varieties, according to recent data. But as plant-based milks gain popularity, a crucial question arises: which option is truly the most sustainable for the environment?
The environmental footprint of our daily milk consumption is complex, extending beyond simple notions of “natural” versus “processed.” Factors like greenhouse gas emissions, water usage, fertilizer requirements, and packaging all play a role. Understanding these nuances is key to making informed choices, and the answer isn’t always straightforward. As Dr. Michalis Hadjikakou, a researcher in sustainable food systems at Deakin University, explains, “There’s a lot of nuance when it comes to making sustainable food choices. You require to consider what the purpose of drinking the milk is.”
Emissions: A Clear Advantage for Plant-Based Milks
When it comes to greenhouse gas emissions, plant-based milks generally outperform dairy. According to the World Resources Institute, a cup of dairy milk generates approximately 330g of emissions, compared to 122g for soy, 102g for oat, and 98g for almond. This difference stems largely from the methane produced by cows during digestion – a significant contributor to Australia’s overall greenhouse gas emissions, accounting for an estimated 11% of the total. Fraser Taylor, managing director of FoodSwitch at the George Institute for Global Health, notes that their updated data, using a 0-100 scale (with 100 being the best), rates soy milk at 96, while dairy milk scores around 85.
FoodSwitch’s ecoSwitch app helps consumers compare the environmental impacts of different foods, and Taylor emphasizes that “Plant-based milks still definitely do have a better environmental footprint than dairy milks, particularly on greenhouse gas emissions.”
Water Usage: Oat Milk Takes the Lead, Almonds Lag Behind
Water consumption is another critical factor. Oat milk emerges as the most water-efficient option, as oats are a dryland crop primarily reliant on rainfall. “Oats are grown in those zones where you’re essentially relying on rainfall with extremely little supplementary irrigation,” Hadjikakou explains. Water usage for dairy and soy milk varies depending on farm location and practices. However, almond milk requires significantly more water due to the Mediterranean climate in which almonds thrive, necessitating regulated irrigation. Taylor confirms that almond milk’s high water usage “brings it down a fair bit” in its overall environmental rating.
Processing, Packaging, and Fertilizers: A More Complicated Picture
While plant-based milks often win out in emissions and water usage, processing and packaging present a more complex scenario. Some research suggests that the processing and packaging of plant-based milks can contribute up to 79% of their environmental impact, compared to just 4% for cow’s milk. However, even when considering these “downstream phases,” Taylor’s data shows plant-based milks still produce about 1kg of CO2 per litre, while dairy milk generates 3kg per litre.
Fertilizer use also plays a role. Soybeans, being legumes, have a natural advantage as they “fix nitrogen” and contribute to soil health. Oat and dairy farming fertilizer needs vary by location, with Victorian dairy farms using approximately 198kg of fertilizer products per milking hectare in 2024-25, down from nearly 250kg in 2020-21. Almonds, however, generally require more fertilizer.
No Single “Winner” in the Milk Sustainability Debate
Hadjikakou concludes, “There’s no clear winner. They each do pretty well at different things.” He suggests a balanced approach, advocating for consumers to vary their milk choices based on intended use. “Perhaps on your latte you could have almond [milk], for your cereal you could have cow’s milk. In that way, you’d still reduce your emissions.”
As consumer awareness of the environmental impact of food choices grows, the debate surrounding dairy and plant-based milks is likely to continue. Further research and innovation in sustainable farming practices will be crucial in shaping the future of milk production and consumption in Australia. The ongoing development of tools like FoodSwitch’s ecoSwitch app will also empower consumers to produce more informed decisions.
What are your thoughts on the environmental impact of different milk options? Share your comments below and help us continue the conversation.
