Chances are, if you walk into your local coffee shop and order a latte, you’ll be asked what kind of milk you want—and the options will be endless. A 2018 University of Oxford study showed that producing a litre of dairy milk results in almost three times more greenhouse gas emissions than a litre of any other plant-based milk. As more people try to reduce their carbon footprint, plant-based options (sometimes called “mylk”) are becoming more commonplace.

If you’ve ditched dairy in favour of plant-based milk, you’re already making a positive impact, according to Dr. Lenore Newman, Canada Research Chair in Food Security and the Environment at University of the Fraser Valley (UFV).

“Dairy has one of the biggest footprints of the major food groups,” explains Newman. “We’re diverting a lot of crops to feed cows.” When you switch away from dairy to an alternative, you make significant savings on greenhouse gas emissions.

Dairy milk produces almost three times more greenhouse gases than any plant-based milk.

Sounds simple, right? As usual when trying to make the most eco-friendly decision, it’s nuanced. Some crops (like soy) are monocultures, meaning they’re repeatedly grown on a large scale on the same land (and that land has to be cleared to produce it). Too many of the same plant species in one area robs the soil of its nutrients.

But while we want to make the most environmentally conscious choice, we also want the food we choose to be delicious and nourishing. Luckily, plant-based products have come a long way in terms of taste. Here’s how the most popular plant-based milks stack up in terms of environmental impact and nutrition.

Bad for bees: Almond milk

Almond milk is much better than dairy milk on greenhouse gasses, but it still has some major issues. It uses the most water by far compared to other crops grown for milks, according to a 2010 report from the Water Footprint Network. And it’s mostly grown in California (which is in a major drought).

“It uses a lot of water, it’s a monoculture and it’s really hard on pollinators,” Newman says. “Because almonds have to be pollinated, they bring almost all the bees in the western part of the continent to the almond farms in California. All this moving around isn’t good for bees.”

A Guardian investigation compared it to “sending bees to war,” as commercial beekeepers transporting their hives to almond farms see them die in record numbers.

Despite its downfalls, almond milk has a much smaller impact on global warming than most US dairy milk and about half the freshwater consumption, according to a study in The International Journal of Life Cycle Assessment.

Nutritionally, “almond milk lacks much protein, but does offer some fat,” says Jennifer Anderson, the registered dietitian behind the popular Instagram account Kids Eat in Color. Almonds themselves are a nutritional powerhouse, offering protein, healthy fats, and fibre. But almond milk consists mostly of filtered water. Levels of fortification vary across brands.

Ethically, it’s not the best option either. “The labour force that harvest the almonds don’t have it really easy,” says Newman. And that’s putting it mildly. According to the July 2020 Covid-19 Farmworker Study led by the California Institute for Rural Studies, an estimated 90% of California farmworkers were born in Mexico, and approximately 60% are unauthorized to work in the US. Their undocumented status means they don’t have access to health care services, and they don’t get sick leave if exposed to Covid-19.

Verdict: Skip the almond milk if other plant-based options are available.

Dairy’s nutritional counterpart: Soy milk

“Soy is a monoculture, so there is some clearing of land to produce it,” says UFV’s Newman. Soy’s water footprint is also larger than peas’, oats’, coconut’s and hemp’s, though it’s nowhere near as high as almond’s. Studies show soy’s greenhouse gas emissions are about equal to almonds’ and peas’, but much lower than dairy’s.

Another issue is that a large percentage of the world’s soy is “Roundup Ready” — genetically engineered to withstand the herbicide glyphosate (Roundup), which the World Health Organization has linked to cancer.

According to a 2013 study in Food Chemistry, genetically modified soybeans contain high residues of glyphosate. Organic soybeans, on the other hand, have a more healthy nutritional profile than other soybeans and come with the major bonus of not being treated with chemical pesticides or herbicides.

Because almonds have to be pollinated, almond farms bring almost all the bees in the western North America to California.

In short, if there are only certain foods you can afford to buy organic, soy should definitely be on that list.

Despite its pitfalls, soy does have a few party tricks. First off, because it’s a legume, it fixes nitrogen in the soil, which reduces the need for synthetic fertilizers. Second, according to a McGill University study, soy milk is the best plant-based milk nutritionally, offering the closest nutritional profile to cow’s milk. That makes it a good option for families with young kids.

“If you are using plant-based beverages with a toddler, it must be high in fat and protein, otherwise it is not nutrient-dense enough for a toddler,” says Anderson.

Verdict: Soy is a great high-protein option, but it’s best to choose organic when possible.

Homegrown and heart-healthy: Oat Milk

“The big winner, and my favourite, is oat milk,” says Newman. “Oat milk is one of the best-tasting options,” she says. And it’s also homegrown. Canada is a top producer of oats and canola.

European brand Oatly generates 80% lower greenhouse emissions than cow’s milk, according to their sustainability report. Land-use is also about 80% lower than cow’s milk, and oats typically use less water to grow than all other milk crops.

But oat milk is likely the least nutrient-dense, according to Anderson. “You need to look at the nutrition facts and compare the brands in your local store,” she says.

The negatives of oat milk: Popular oat products like instant oatmeal, breakfast cereal and snack bars were tested for glyphosate in an Environmental Working Group study. Roundup was present in almost all the products made with conventionally grown oats, and almost 93% of those samples had glyphosate levels higher than what EWG scientists consider safe for children.

Organically grown oats fared better, with only about 30% of the samples containing glyphosate, all at much lower levels. Oats, while a monoculture “are usually grown on previously farmed land, so the issue is subtle,” says Newman.

Verdict: Oat milk is a great heart-healthy option, especially if you choose organic.

Honourable mentions: Pea and Coconut

Pea milk has a lot in common with soy. It’s high in protein (and often has added fat), making it another good dairy alternative for toddlers. Because they’re also legumes, peas replenish nitrogen in the soil. Unlike soy, peas are less likely to be genetically modified to be Roundup Ready. Pea is one of the more expensive options on the market, though, so for families who drink a lot of plant-based milk it might be a better occasional purchase.

As for coconut, it is a good option, says Newman “because it is usually farmed in mixed plantations with other species, and it brings money into parts of the world that really need small industry.” The downside is, “you have to bring it halfway around the world, so there is a bit of a carbon footprint.” Also, when you’re picking out a coconut milk, look for one that’s Fair Trade (and therefore produced more equitably).

Where to go from here

“The real truth is that dairy is rising in popularity around the world on average,” says Newman. “It’s weird because North Americans are moving away from it. What happens if everyone else uses as much dairy as North Americans? The answer is: You just can’t do that.”

Can we single-handedly save the planet by choosing plant-based milk? Or save the bees by avoiding almond milk? Probably not. But at least our morning coffees don’t need to be part of the problem.