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From dairy to soy to oat to almond, these are the milks with the highest and lowest carbon footprints.
Words by Seth Millstein
Breast milk is the first food we eat as newborns, and for many people, some kind of milk continues to be a dietary staple for the rest of their lives. But the production of dairy milk is bad for the environment, which has many milk-lovers seeking out plant-based alternatives to cow’s milk. There are a whole lot of options — but which milk alternative is best for the environment?
There are a number of factors to consider when gauging environmental impact, but one thing is abundantly clear: Regardless of which plant-based milk is the best for the environment, all of them are better than dairy milk, from a climate standpoint.
Cow’s milk is worse for the environment than any other kind of plant-based milk. This is not debatable or unclear; in terms of land use, water use and greenhouse emissions, the production of cow’s milk causes much more damage to the planet than any milk alternatives, and it isn’t particularly close.
A 2018 study estimated that dairy emits around three times more greenhouse gasses than any plant-based milk alternative. A portion of these gasses come from the cows themselves — specifically, their burps and their manure — but producing their feed, fertilizing the soil and various other activities on dairy farms also emit greenhouse gasses.
If that wasn’t bad enough, cow’s milk requires nine times more land to produce than even the most land-intensive plant-based milk alternative. Creating a liter of dairy milk requires 8.9 square meters per year; by contrast, oat milk, soy milk, almond milk and rice milk all require less than one square meter for the same output.
Lastly, dairy milk requires an extraordinary amount of water. It takes 628 liters of water to make just one liter of milk; even almond milk, which is notoriously water-intensive to farm, uses just 59 percent of the water dairy milk takes to produce.
Of course, cows aren’t the only animals who produce milk. Goat milk has become increasingly popular in recent years, and to a lesser extent, so has sheep milk. Are they more environmentally friendly options than cow’s milk?
Unfortunately, no. They encompass a much smaller share of the market than cow’s milk, but on a per-capita basis, producing goat and sheep milk actually emits more CO2eq per kilogram than cow’s milk — 2.3 times more, to be precise. Given that cow’s milk already emits three times more greenhouse gas than plant-based milk, goat and cow’s milk are not good alternatives for environmentally friendly consumers.
In terms of greenhouse emissions, soy milk has the lowest carbon footprint overall. But according to Our World In Data, producing one liter of almond milk emits just .7kg of CO2eq, less than any other milk alternative.
But of course, emissions are only part of the story. Water use also plays a huge role in determining a food’s environmental impact, and while almond milk produces relatively few greenhouse gasses, it requires an extraordinary amount of water — 371 liters per liter of milk — compared to other plant-based milk alternatives.
Further complicating the matter is the fact that almond milk, despite its high water use, requires less land than almost any other plant-based milk. Only rice milk has a smaller land footprint — but it also emits a lot more greenhouse gasses than almond milk.
All of this is a long way of saying that there’s no single metric for assessing a food’s environmental impact, simply because there are so many different ways in which food production can affect the environment. All of those impacts are important in their own ways and have to be weighed against one another.
With that being said, if we take a holistic view, we can come to some rough conclusions about which plant-based milks are best for the environment. Let’s take a look.
Source: Our World in Data
In totality, soy milk is among the most environmentally friendly milk alternatives on the market. Its land use, water use and greenhouse emissions are all very low compared to other plant-based milks.
Oat milk is also very environmentally friendly. Its land use and greenhouse emissions are comparable to that of soy milk. Its water use is twice as high as soy milk, but it’s still much lower than many of the other plant-based milks on this list, and is an excellent choice for any milk-lovers looking to reduce their environmental footprint.
Rice milk requires more water and emits more greenhouse gas than oat or soy milk — though again, still much less than dairy milk. On the plus side, it requires very little land compared to other plant-based milks.
Several plant-based milks have only recently hit the mainstream, and haven’t yet been studied as in-depth as many of their predecessors.
Pea milk is one such alternative, and while large-scale studies of its environmental impact are still pending, it requires relatively little water to produce, and one industry-funded study found that pea milk’s carbon emissions are comparable to oat and soy milk — that is, very low.
Another relative newcomer, hemp milk is also a promising alternative to cow’s milk. Though it hasn’t been studied as rigorously as some other milk alternatives, one study found that producing hemp milk has around half the environmental impact of cow’s milk.
More generally, hemp plants trap carbon from the air, require little to no pesticides to grow and are good for soil health. Hemp is also appealing because, unlike many other crops, almost every part of the plant can be used for one purpose or another.
A downside to hemp milk is that it requires a lot of water to produce — more than oat, soy or pea milk, but still less than almond milk. Nevertheless, its many other environmental benefits make it a very attractive option for the environmentally conscious milk-drinker.
Though not as well-known or ubiquitous as other milk replacements, hazelnut milk is environmentally friendly in more than one way. Hazelnut trees require relatively little land and water to farm, are pollinated by the wind rather than commercial honeybees and sequester carbon.
Almond milk and coconut milk are two other popular alternatives to cow’s milk. From an environmental standpoint, both have some attractive qualities: Almond milk emits less greenhouse gas and requires less land than dairy, while coconut trees sequester carbon and require little water to grow.
But both also have some downsides that make them less sustainable than other plant-based milks.
Almond milk, as previously mentioned, requires an exorbitant amount of water to produce. That’s an especially big problem given that 80 percent of almonds are grown in California, where extreme droughts are common and groundwater is being depleted more rapidly than almost anywhere else in the world.
Coconut milk has a whole other host of issues. Though coconut trees sequester carbon, producing coconuts is extremely land-intensive and is a leading cause of deforestation in some countries. It’s also harming animals: Coconut plantations have been linked to the extinction of two species (the Marianne white-eye, a bird, and Ontong flying fox), and one study found that 66 species on the IUCN Red List are impacted by coconut production.
Perhaps most disturbingly, some coconut farms in Thailand have been caught forcing monkeys to collect coconuts, a process that involves separating them from their families and keeping them in chains when they’re not working. Several companies have stopped sourcing coconut milk from Thailand because of this practice.
It’s worth noting that Thailand is the only country that’s been confirmed to use monkey labor to produce coconuts, so this isn’t a problem inherent to the fruit itself. If you’d like to use coconuts without potentially supporting this slave labor, it’s best to avoid buying coconut products that come from Thailand, and instead opt for these monkey-friendly brands (keeping in mind that coconut milk is not the most environmentally sustainable plant-based option).
There’s no one plant-based milk that’s definitely “better” for the environment than all of the rest. The most important takeaway is that all plant-based milk is much better for the environment than dairy, so if you’d like to swap out cow’s milk for a more environmentally-friendly alternative, you have no shortage of options at your disposal. All of them have their upsides and downsides, and some need more studies to paint the full picture of their environmental impacts.
That said, when taking all factors into account, soy milk and oat milk are generally the most environmentally friendly. Hemp milk, pea milk and hazelnut milk are all very promising options as well, though their long-term impacts need to be studied more before reaching any definitive conclusions.
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