How Oat Milk Can Help Save the Environment

While a small switch in a morning routine, alt milks can be a real factor in lowering our everyday greenhouse gas emissions. The proliferation of alternative milks leads to a question of which is the best for the planet.

By
Taylor Goto
May 12, 2021

C+S 2021 students are blogging about topics that interest them for Applications in Climate and Society, a core spring class.


I love chai lattes. The warm spices and frothy milk is the pick me up I look forward to every day. The perfect iced chai latte with oat milk goes for around $7 near my apartment. This outrageous price is all but worth the upcharge of 50 cents to switch to oat milk.

This extra charge to have my drink made with what is obviously the superior alternative milk is worth it to me. Firstly, I am very lactose intolerant and real milk can do some serious damage. But more importantly, not just oat, but alternative milks, in general, are better for the environment. While a small switch in a morning routine, alt milks can be a real factor in lowering our everyday greenhouse gas emissions.

The proliferation of alternative milks—a billion-dollar industry in the U.S. alone—also leads to a question of which is the best for the planet.

A bar chart showing the market share of various alternative milks.

Cow’s Milk

Dairy milk is the worst for the environment. A 2018 study by Oxford University shows that a glass of cow’s milk has at least three times more emissions than any alternative milk. Don’t get me wrong, I love a good old-fashioned creamy chai latte with whole milk. It’s my dirty secret I sometimes get when I am feeling down.

Unfortunately, a liter of cow milk requires 1,050 liters of water to produce. This is a wild amount of resources. In terms of greenhouse gases, a 200 milliliter glass of cow’s milk creates around 0.6 kilograms of carbon dioxide.

The cost of milk remains low in the U.S. thanks to government subsidies. In New York, the average price of milk is $1.97 per gallon. While accessible, better alternatives for the resource-consuming beverage are available today.

Soy Milk

Soy milk is my second favorite alternative. The original alt milk, soy has been the staple for nondairy users. In terms of water usage, a liter of soy milk requires 297 liters of water to produce. While soy uses a third of the water needed for dairy, alternatives such as oat are more water efficient.

In terms of greenhouse gas emissions, 200 milliliters of soy milk creates 0.195 kilograms of carbon dioxide. This number is a third of the emissions of dairy and at the price point of $1to $3 per half gallon, makes soy an excellent sustainable alternative milk choice.

Almond Milk

Almond milk is currently the most-purchased alternative milk in the marketplace. Sadly, almond milk is quite bad for the environment. A single almond requires 12 liters of water to produce. While it doesn’t contribute to the consumption of animal products, almond milk should not be the go-to alternative for its environmental benefits.

That said, almond milk shines in greenhouse emissions created. Two hundred milliliters of almond milk emits 0.14 kilograms of carbon dioxide, which is the lowest of any other compared alternative. The price point is $4 per half gallon, and it’s readily available at coffee shops or grocery chains.

Oat Milk

Oat milk is a personal favorite of mine. It’s also a growing favorite of others as well as there is currently a nationwide shortage of oat milk. I feel it is the most creamy when frothed and has the bonus of the lowest overall carbon footprint.

In terms of water, a liter of oat milk requires 48 liters of water to produce. This is significantly lower compared to the water usage to produce dairy, soy, and almond milks! Oat milk also has a relatively low greenhouse footprint, with carbon dioxide emissions at 0.18 kilograms for a 200 milliliter glass.

The one true fallback of oat is its price point at around $5 per half gallon. Oat’s price point is significantly higher than other alternatives and it’s also less readily available than its competitors.


Picking which alternative milk is best for the environment is not a simple task. There are many factors such as water usage and greenhouse gas emissions associated with each. Generally speaking, oat wins for overall sustainability. For price point, though, soy wins. Picking an alternative milk should factor in personal tastes preferences as well as educating oneself in the environmental impacts of each option. In my heart, oat milk is the superior alt milk. But ultimately, switching away from cow’s milk to any non-dairy option is a good personal switch for the planet and your stomach.