Dairy vs plant-based milk - what's the best for the planet?

With the most popular milk alternatives being soy, almond, rice, and oat milk it is important to know how they rank in terms of environmental impact. Before we go any further, any milk you choose which does not come from an animal is already much better for the environment so that is a very big win no matter which one you choose. The impact of food on our planet is wide-ranging including things like; greenhouse gas emissions (GHGe), land use, water use, eutrophication potential, soil acidification and the list goes on and on.

In this quick review, we will just look at GHGe, land use and water use as these issues contribute to water-scarce areas and times of the year, driving 90-95% of global scarcity-weighted water use (1). Almost 43% of the world’s ice and dessert free land is used for agriculture which has profound impacts on our biodiversity, and GHGe produced by agriculture is around 26% of global emissions.

Image adapted from (3) and data from (1)

With almond milk being the most water-intensive of the plant-based milks to produce, one glass is very close to the 65.1 litres of water used in the average shower which lasts for 8.2 minutes at average flow rate 7.9 litres per minute.

Having a glass (200ml) of dairy milk daily produces the same emissions as driving 535 miles, which is only 40miles short of doing a return drive from London to Paris (2). Whereas having the same amount of almond milk roughly works out to 156 miles driven. When looking at all results there is no out and out winner, considering the dramatically higher water usage of rice and although no the best, almond and that soy and oat milk are both low on all three parameters I would suggest using one of those two milks.

However, taste is an important factor and if you only like rice milk for example then go for it, as any plant-based milk beats dairy milk in every single earth destroying category. Another simple option for those not wanting to change from their current dairy slurping, or simply for those who want to improve their environmental impact even more then consider reducing your milk consumption in favour of good old fashioned water. These are just some simple options, what milk will you choose or do you already choose, why is that and are you going to change it after reading this information?

What about the healthiest milk? We’ll post on that in the coming week so keep tuned.

Thanks to @skelbies for the great question! :)

The evidence

1) Supplementary Materials for Reducing food’s environmental impacts through producers and consumers Poore and Nemecek (2018), Science. Additional calculations.

2) https://www.epa.gov/energy/greenhouse-gas-equivalencies-calculator

3) https://www.bbc.com/news/science-environment-46654042