Milk versus Plant-based Milk Products, How Sustainable are They?

When it comes to the dairy cooler of your market, there is no shortage of options. Not only is there milk, but almond, soy, coconut, and oat “milk.” Unless you are allergic or vegan (see below regarding lactose intolerant), choosing between these products could come to a choice of which product is the most sustainable. According to Nielsen’s Global Health and Wellness survey, 44 percent of Generation Z said ingredients sourced sustainably are very important in their purchase decisions, followed by Millennial (38%) and Generation X (34%) respondents.

When it comes to sustainability, each product affects the environment in different ways when it comes to greenhouse gases, but there are other factors to consider such as packaging, energy, transportation and other uses from the byproducts to make your milk. Some of the information below will assist when it comes to making a choice the next time you are at the market.

Cow Milk

There have been stories in the media regarding animal agriculture and its contribution to the greenhouse gas methane. According to the EPA, methane accounts for about 10 percent of the total of greenhouse gases emitted and of that total, methane production from cows accounts for 36 percent when including manure management. While methane is 21 times stronger than Carbon Dioxide (CO2), it stays in the atmosphere about 12 years versus 50 to 200 with CO2. Researchers are working to stem the amount of methane produced from cows by changing their diet and with microbes in wastewater facilities.

Another factor to consider is small dairy farmers. Despite efforts from the Trump administration to assist dairy farmers, the rate of small dairy farms closing is substantial. An online search of “dairy farm crisis” reveals not only the numbers but the effects on farmers’ mental health and their families. The closings also affect rural communities with a loss of dollars spent in those communities.

Other factors to consider for sustainability are that milk is not transported over long distances, their diets are not only forages but byproducts from the processing of other agriculture products. Cow manure is spread onto fields, bone and blood meal is used in some organic production. And as much as you probably don’t like to think about it, they are sold for ground beef, and they are several products that come from cows such as medicines, lubricants, leather and many ingredients in household products.

Almond Milk

Sales of almond milk have grown by 250 percent to 894 million dollars in 2015, according to Nielsen. When it comes to purchasing almond milk, the most significant sustainability issue is water. California is the largest producer of almonds and in the midst of a severe drought. It is estimated that it takes between 960 to 1,611 gallons of water to grow and process one liter of almond milk (this compares to 77 to 277 gallons for cow milk production).

Regarding greenhouse gases, almonds produce more Carbon Dioxide, but when compared to cows it produces less overall greenhouse gases. Any greenhouse gas factor is Nitrous Oxide (N2O) which almonds produced more due to fertilizer use. While N2O is not a significant greenhouse gas, accounting for 6 percent of total emissions, it is 300 times more potent than CO2. In a UCLA study conducted in 2016 analyzing the life cycle assessment comparing CO2 emissions, for every 1 liter of milk almond milk was much lower at 0.3637kg versus 1.67kg for dairy cows.

There are two other factors to consider when considering sustainability, transportation and lack of use for byproducts. Almond milk is transported across great distances to reach markets. Thus emissions from this factor could negate the difference in CO2 emissions. The manufacture of almond milk produces over 4.3 billion pounds of almond hulls per year. Some of that is being recycled for animal feed and bedding, which seems like a bit of irony since it is slowly replacing the cows, but there is still a large portion to recycle. While researchers are working on creating biomass for fuel, plants in California are closing. USDA researchers are also developing compostable bioplastics, but there is no timeline when it will come into fruition. While it would only make a small dent in the number of hulls, hard cider and IPAs are also being used to create craft brews from the hulls.

Soy Milk

As with almond milk, there are the same considerations when considering sustainability. According to a study conducted by David Pimentel of Cornell University, it takes about 14 calories of fossil-fuel energy to produce one calorie of milk protein (organic milk is 10 calories) versus 0.26 calories of fossil fuel for a calorie of organic soybeans. Based on these figures, soy is more energy efficient for protein as they both contain about the same amount. In regard to water use, it takes approximately 78 gallons of water to produce one liter of soy milk.

Other sustainability factors to consider are sourcing of non-GMO soybeans as most milk is produced with them. Despite a double-digit growth in the planting of these beans as compared to last year, the yield was expected to decline seven percent, according to Research and Markets. The study also states, “US organic soybean supplies are projected to be insufficient over the 2017/18 marketing year, as the flow of organic soybean imports has slowed significantly. Over the 2017/18 marketing year, the author expects US organic soybean imports to reach 15.1 million bushels, up only 1% y/y.” To meet the demand of soybeans needed for soy milk (along with organic animal feed), they would also need to be imported. This importation would not only add CO2 to the atmosphere, thus negating any savings. There are also fears of rainforests being cleared for soya production in Brazil. Also contributing to the CO2 equation is the transportation costs to markets of the finished soymilk.

Oat Milk

Oat milk is a relative newcomer to the alternative milk game, but its popularity is rising. While not available in most stores, oat milk gained popularity first in coffee shops. The biggest maker of oat milk is a Swedish company, Oatly. Rather than using the same process as other plant-based milk of using water to extract the “milk,” they use an enzymatic method. There are no facts as to the amount of water used in making the product or growing the oats. Currently, Oatly is selling the byproduct from making oat milk to a local pig farm. Over the objections of vegans, the company states this is the most sustainable option. As with other milk alternative products, there is a large amount of electricity in the production of these products and transportation contributing to CO2.

Other Plant-based Milk

In addition to those discussed above, there are several others that have the same considerations when it comes to the sustainability of the product. With cashews, most are produced overseas in Vietnam, India and Nigeria as the primary producers. With the shells and other byproducts, the question is are they used for biofuels or other purposes. Transportation in shipping containers, along with the electricity, water required and the treatment of workers should be considered. Coconut milk has the same issues as only a few countries grow coconuts and the destruction of native vegetation needed for demand. While rice milk is good for those with allergies, the paddies produce 20 percent of the total manmade methane into the atmosphere through a process called methanogenesis. Stefan Unnasch, a researcher with Life Cycle Associates, which was hired by Ripple, a maker of pea milk conducted a study and found that producing one liter of pea milk results in 387 grams of carbon dioxide emissions, one liter of soy milk, 397 grams of carbon dioxide.

Finding figures for factors other than production is difficult. Transportation accounts for about 11 percent of 8.1t CO2 e/y footprint for food production with an additional four percent from producer to retail. “Buying local” could lower this carbon footprint and a factor when buying any of these products. Having this information in one article will hopefully help with this decision as I have several links to give you further information.






*(The reason I don’t specify lactose intolerant is there are some dairy products that are tolerable including Lactose-free milk or Fairlife milk. Therefore, you can choose between all those mentioned).



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