Oat milk vs Almond milk: Carbon Footprint Compared

Overview

When standing in the plant-based milk aisle, the choice often comes down to two heavyweights: oat milk vs almond milk. While both options significantly outperform dairy milk—which produces roughly three times the emissions of any plant alternative—they are not environmentally equal.

Oat milk has surged in popularity due to its creamy texture and low environmental impact. Almond milk, the long-standing market leader, is often criticized for its heavy water usage. In this comparison, we look past the marketing to analyze the lifecycle greenhouse gas emissions, land use, and water consumption of these two staples to determine which is truly better for the planet.

The Numbers

When looking at the climate impact of oat milk vs almond milk, we measure success in kilograms of carbon dioxide equivalent (CO2e) per liter produced. According to data from the landmark Poore & Nemecek (2018) study published in Science, the differences are nuanced but clear.

• Oat Milk: Produces approximately 0.9 kg CO2e per liter. It requires about 0.8 square meters of land and 48 liters of water per liter of milk.
• Almond Milk: Produces approximately 0.7 kg CO2e per liter. While its carbon emissions are slightly lower than oat milk, it requires significantly more water—about 371 liters per liter of milk—and roughly 0.5 square meters of land.

At first glance, almond milk appears to "win" on pure carbon emissions. However, carbon is only one part of the ecological footprint. The environmental "cost" of almond milk is heavily weighted toward water scarcity in regions like California, whereas oat milk's footprint is more evenly distributed across carbon and land use.

Why the Difference in Oat Milk vs Almond Milk?

To understand why these two milks have different footprints, we have to look at how the raw ingredients are grown and processed.

1. Water Scarcity and Almonds

Almond milk’s primary environmental hurdle is water. Over 80% of the world's almonds are grown in California, a region prone to severe droughts. One glass of almond milk requires roughly 74 liters of water—more than any other plant milk. This places immense pressure on local aquifers and ecosystems. Oats, by contrast, are often rain-fed and grown in cooler climates (like the Northern US, Canada, and Europe) where water stress is less prevalent.

2. Fertilizers and Nitrous Oxide

Oat farming often requires more nitrogen-based fertilizers than almond trees. The production and application of these fertilizers release nitrous oxide, a potent greenhouse gas. This is a primary reason why oat milk has a slightly higher CO2e per liter than almond milk. However, many oat farmers are now adopting regenerative practices to reduce this reliance.

3. Land Use and Biodiversity

Almonds grow on trees, which can actually act as carbon sinks over their lifetime. However, almond monocultures can be detrimental to local biodiversity, particularly honeybee populations that are shipped in by the millions to pollinate the groves. Oats are annual crops that can be integrated into crop rotations, which helps maintain soil health if managed sustainably.

What You Can Do

Choosing between oat milk vs almond milk is a step in the right direction compared to dairy, but you can further reduce your impact with these tips:

• Check the Label: Look for brands that prioritize "Glyphosate-Free" oats or organic almonds to ensure fewer synthetic chemicals are entering the ecosystem.
• Consider the Source: If you live in a water-stressed area, oat milk is the clear winner. If you are focused strictly on the lowest possible carbon emissions and live near almond-growing regions, almond milk is a strong contender.
• Avoid Food Waste: Plant milks have different shelf lives once opened. Ensure you buy the size you can consume to avoid the "embedded emissions" of wasted product.
• DIY Your Milk: Making oat milk at home is incredibly simple (blend oats and water, then strain). This eliminates the emissions associated with industrial processing, packaging, and shipping heavy liquids.

The most impactful choice you can make is removing dairy from your diet, but refining your plant-based choices helps push the needle even further toward a sustainable future.

See how your beverage choices impact the planet by using our carbon calculator to estimate your personal footprint.