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  • Megan at ZeroSmart

What Kind of Milk is Most Sustainable?

Updated: Oct 21, 2022

It has long been discussed that the production of cow’s milk, from dairy cows, has devastating effects on the environment. 60% of global methane emissions come from human activities and 27% of this comes from animal agriculture. The first problem of dairy cows is the amounts of methane that they produce. The second problem is that there are just so many of them. There are 270 million cows who have been bred into existence for their milk.


Because of methane emissions and other climate-destroying processes, the 13 largest dairy firms in the world have been found to have the same combined greenhouse gas emissions as the whole of the United Kingdom.


So while the milk you add to,on,your coffee may not seem like a big deal, it actually adds to a significant amount of your daily greenhouse emissions. Drinking cow's milk in your coffee will account for two-thirds of the carbon footprint of your drink.


A less discussed issue is that just because something is vegan, it does not automatically make it good for the environment. In this guide we are going to compare the eco-friendliness of some of the most popular milk types (both plant-based and animal-based), based upon the water usage in their production, CO2 emissions and land usage when grown.



Plant Milk


Soy Milk

Water Consumption per 200ml: 59.4 litres

CO2 Emissions per 200ml: 0.196kg of CO2e

Land Usage: High


Soy milk is a plant-based non-dairy beverage that’s a popular alternative to cow’s milk. It’s made from soybeans, and many brands also add vitamins and minerals, such as vitamin D and calcium. For the long time before the vegan market boomed, soy was the most readily available option for the non-dairy milk drinkers.


Soy milk is pretty good for the environment. A 200ml glass of soy milk is responsible for 0.196kg of CO2e. One litre of soy milk costs around 297 litres of water to produce. This is approximately one third of the water needed to produce cow’s milk.


Unfortunately, the land use of soy milk is its biggest downfall. It currently uses lots of land, in vulnerable locations like the Amazon rainforest. Since 1990 the area of land planted with soybeans in Amazonian states has expanded at the rate of 14.1 percent per year and now covers more than eight million hectares.

The mass clearing of the Amazon rainforest to make room for growing soybeans. Credit: Greenpeace.

litersliterlitersone-thirdlandsthatliters,litersliters 80% less land to grow than dairy milk requires.

Examples of “Oatly!” oat milk drink. Available in different flavours and versions.

Rice Milk

Water Consumption per 200ml: 54 litres

CO2 Emissions per 200ml: 0.3kg

Land Usage: High


There are plenty of heart-healthy nutrients in rice milk. Unsaturated fats present in rice milk help reduce cholesterol in the blood. Vitamin B6 also helps maintain heart health. It is very similar in taste, flavor, and texture to cow’s milk.


As can be seen from the graph below, rice milk is associated with higher greenhouse gas emissions compared to other plant-based milk (at 0.3kg of CO2e per 200ml glass). This is because the water-intensiverice needs to be grown in standing water, and rice paddies are full of methane-producing bacteria.


Rice is a very water intensive crop to grow, taking 3,000-5,000 liters of water to produce 1 kg of rice. Growing rice also takes about 10% of the world's arable land. It is important to remember that these statistics are not reflective of the rice milk industry only. Rice is a huge crop, being a clear-cutlabor aple food for half of humanity or more than 3 billion people globally.



Coconut Milk

Water Consumption per 200ml: 0.5 litres

CO2 Emissions per 200ml: 2.1 kg CO2e to produce 1 kilogram of coconuts

Land Usage: High


Coconut trees use significantly less water than dairy cows, and they also absorb carbon dioxide, which is great. However, since coconuts are usually grown in tropical areas, the transportation drives up the carbon footprint.


It is the land needed, however, which causes problems. According to an investigation by The New York Times, between 2007 to 2014 rainforests in Indonesia were clear cut at the rate of three acres per minute to make way for coconut palm trees. Because coconuts can only be grown in tropical areas, land pressure becomes more extreme. Increasing global demand for coconut milk is likely to put further pressure on the environment and wildlife in these areas.


There are also labour issues associated with coconut production in low- and middle-income countries like Indonesia, India, and the Philippines, where coconut pickers are sometimes paid less than a dollar a day (to support fair wages, look for certified Fair Trade coconut products).



Hemp Milk

Water Consumption per 200ml: 3,685 liters of water to produce 1 kilogram of hempseed

CO2 Emissions per 200ml: Unkown

Land Usage: Low


The exact figures on the water consumption and CO2 emissions of hemp milk are still to be found. There is not much research being done. This is because there are still only 20 UK farmers who are currently licensed to grow hemp. It is still a very new industry.


Hemp milk is a non-dairy beverage made by blending water and seeds from the hemp (cannabis Sativa) plant. It has an earthy, nutty flavormeters and a creamy consistency. It is known as an environmental game changer. It does not need pesticide chemicals or much water input (more water than soy, but less than almond and dairy).


Hemp roots also grow up to 3 metres deep, so they could help improve soil structure and nutrient levels, potentially leading to greater yields in follow-on crops - incorporating regenerative agriculture practices into its growth.

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As previously mentioned, only 20 UK farmers are currently licensed to grow hemp who source most of their seeds from Europe and Canada. This of course increases its carbon footprint. It also means that there is currently very little research on its carbon footprint.


Hemp milk is in early development, however it holds promise to become an environmentally sustainable milk alternative.



Cashew Milk

Water Consumption per 200ml: 14,218 litres of water necessary to produce 1 kilogram of cashews

CO2 Emissions per 200ml: 2.0 kg CO2e necessary to produce 1 kilogram of cashews

Land Usage: Low


Cashew milk is another nut milk alternative. Unfortunately, cashews are extremely thirsty plants. It has been estimated that every pound of cashews produced requires a huge 1,704 gallons of water (7,746 litres).


They also have high food miles - cashews are primarily produced in India, Vietnam and Africa. In addition to the miles that they have to travel to get to us, those grown in Africa are often transported to India and Vietnam to be processed. A lot of stages are involved in the processing phase and Africa producers often do not have the modern machinery to make it easier. The carbon footprint for these cashews are even higher due to the extra travel.

Cashew nuts, used to make cashew milk.

Despite this, one of the main advantages that cashew milk has over dairy milk is the little land that is needed. Cashew farmers can also adopt different planting systems to ensure the optimal yield per area. Despite this coming with its challenges, for cashew milk drinkers, this is good news.



Macadamia Milk

Water Consumption per 200ml: 9,000 liters of water to produce one kilogram of macadamia nuts

CO2 Emissions per 200ml: 2.0 kg CO2e to produce 1 kilogram of macadamia nuts

Land Usage: Moderate


Macadamia milk requires significantly more water to grow and produce than almond milk or dairy milk. It takes approximately 9,000 liters, of water to produce one kilogram of macadamia milk. However, the areas where macadamia nuts are commonly grown have been coping with severe water shortages and other climate-related crises, such as Australia, Hawaii and other tropical regions.

A map showing macadamia growing regions. Often areas which suffer from drought.

The carbon footprint of macadamia milk is moderate. Approximately, 2.0 kg CO2e to produce 1 kilogram.


Macadamia nuts are considered to be moderately sustainable due to having lower environmental damage to air, water, land, soil, and forests, as long as pesticides have not been used.






Animal Milk

Goat’s Milk

The first non-plant milk we are going to discuss is goat’s milk. Though goat’s milk still only accounts for 0.02 percent of milk consumption in the US, it’s jumped by nearly a third since 2007. Sales have jumped 15 percent, and in some places, goat herds have swelled.


Goats produce dairy milk that shares many of the same environmental impacts as cows and other livestock―habitat destruction, water use, and carbon emissions. Goat’s milk is not significantly better for the environment than cow’s milk, especially compared tonon-dairy, plant-based alternatives. However, it does have a few advantages over cow’s milk.


Goat farming requires less water and land than cattle farming, and they produce less manure―presenting a low threat to nearby water sources. Additionally, the goat farming industry is considerably smaller than that of the cow’s industry, and thus is primarily absent from mass-milking operations and large agribusiness corporations.


Goat farming requires less water and land than cattle farming. The goat farming industry is also considerably smaller than that of cow’s, and thus is primarily absent from mass-milking operations.


Livestock production accounts for 4.2 percent of total US greenhouse gas emissions, with 0.01 percent from goats. Goat’s milk's carbon emissions come largely from its transportation. Which is larger than cow’s milk because there are not as many farms.

One of the environmental benefits of goat’s milk is that they take up less space.

Cow’s Milk

Cow’s milk has significantly higher impacts than plant-based alternatives across all metrics. It causes around three times as much greenhouse gas emissions; uses around ten times as much land; two to twenty times as much freshwater; and creates much higher levels of eutrophication.


For more information on the dairy industry, there are some incredible vegan documentaries.


Conclusion


The “most sustainable milk” is highly dependent on your priorities. Are you more concerned with the land used or the carbon footprint for it to get into your fridge? That isn’t something we can tell you. From what we have found, here is the milk in order of most sustainable to least:


Oat Milk:

Water Consumption per 200ml: 40 liters

CO2 Emissions per 200ml: 0.14kg

Land Usage: Low


Coconut Milk:

Water Consumption per 200ml: 0.5 litres

CO2 Emissions per 200ml: 2.1 kg CO2e to produce 1 kilogram of coconuts

Land Usage: High


Soy Milk:

Water Consumption per 200ml: 59.4 litres

CO2 Emissions per 200ml: 0.196kg of CO2e

Land Usage: High


Almond Milk:

Water Consumption per 200ml: 74 liters

CO2 Emissions per 200ml: 0.14kg

Land Usage: High


Rice Milk:

Water Consumption per 200ml: 54 litres

CO2 Emissions per 200ml: 0.3kg

Land Usage: High


Hemp Milk:

Water Consumption per 200ml: 3,685 liters of water to produce 1 kilogram of hempseed

CO2 Emissions per 200ml: Unkown

Land Usage: Low

Macadamia Milk:

Water Consumption per 200ml: 9,000 liters of water to produce one kilogram of macadamia nuts

CO2 Emissions per 200ml: 2.0 kg CO2e to produce 1 kilogram of macadamia nuts

Land Usage: Moderate

Cashew Milk:

Water Consumption per 200ml: 14,218 liters of water necessary to produce 1 kilogram of cashews

CO2 Emissions per 200ml: 2.0 kg CO2e necessary to produce 1 kilogram of cashews

Land Usage: Low

Goat’s Milk

Cow’s Milk


At ZeroSmart, we always go for the plant-based options and in this case, we prioritize the carbon footprint of the beverage. Purchasing mindfully is as important as what you are buying - only buy what is going to be consumed and check if you can get locally made milk.


What milk is your milk of choice? Let us know on Instagram @ZeroSmartUK








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