Is milk bad for environment? It’s complicated!

  • Date: May 14, 2022

Although the sales of cow’s milk is falling as more people opt for plant-based varieties, it still dominates the market by some distance. More people are beginning to understand the environmental implications of a diet containing meat – but how does this translate into dairy produce? And more specifically, is milk bad for the environment?

High carbon emissions in milk production

Greenhouse gas emissions is a hot topic when it comes to leading a more environmentally friendly life – and rightly so. These types of gases can lead to the warming of the planet which can cause different species to become extinct as their habitats become altered. It is a massive global threat. 

According to the United States Environmental Protection Agency (EPA), 10% of greenhouse gas emissions in 2019 came from the agriculture sector. Dairy farming contributes to this. Cows produce methane, a greenhouse gas, as part of their normal digestive physiology. And with 270 million dairy cows worldwide, that’s a lot of methane! But it doesn’t stop there. Methane is also produced when their manure is stored in lagoons, for example.   

The cows obviously need fed too, which brings its own greenhouse gas emissions. Nitrous oxide, another type of greenhouse gas, can be emitted in different agricultural processes. The use of chemical pesticides and some irrigation practices, for example, can lead to the release of nitrous oxide into the atmosphere.

 In terms of emissions, you’d be forgiven for thinking it is all doom and gloom when it comes to drinking cows’ milk. However, as technology has progressed, the production of cow’s milk has improved in an eco-friendly way in some countries. The UK, for example, has taken significant strides in reducing carbon emissions associated with cow’s milk.  Northern Ireland farmers have decreased the amount of greenhouse gases emitted during milk production by over 30% per liter since 1990. Making tweaks to the way things are done can improve the ‘green’ credentials of an activity significantly.

Land use in dairy farming

Dairy cows need a place to live. Plant-based milk production also requires land to grow crops. However, in dairy farming the cows need land AND the food that they eat needs space to grow! This has significant implications for the environment. Making space can lead to a loss of biodiversity as habitats are lost. High levels of water pollution also exist around highly farmed areas due to potential for a greater amount of runoff. It isn’t all bad news though. Often cow feed is waste from other industries that would have been thrown away anyway. For example, grains that have been recycled after the use in food and beverage production.

Intensive land use can also lead to soil degradation. Grazing by lots of livestock can lead to bare soil – this, in turn, can lead to infertile land and increased chance of flooding. Soil degradation also leads to poor plant growth meaning that there are less plants available to absorb carbon dioxide from the atmosphere.  To compound this effect, degraded soil actually releases carbon (which it had stored up) in the form of carbon dioxide. This is also a greenhouse gas and will contribute to global warming. It is estimated that over half of the agricultural lands in the U.S. have an element of soil degradation.

Water use in cow’s milk production

A large amount of water is needed in the production of cow’s milk.  Water is needed for different parts of the production – from the water needed to grow their food to the water that they drink. In 2018 it was estimated that for every liter of cow’s milk produced, 628 liters of water is needed. With the average U.S. adult drinking nearly 70 liters of the stuff a year, the water use adds up.

Other milk alternatives are available, and they all use less water per liter of cow’s milk. Only 28 liters of water is needed in the production of a liter of soy milk – quite a massive difference!

The bottom line

In terms of land use, water footprint and carbon emissions cow’s milk rates poorly. From the more obvious impacts such as soil degradation to the nitrous oxide emitted during the cattle feed production, the impact is wide ranging. Some countries have more sustainable approaches to milk production than others therefore the impact is largely location dependent. However, the overall evidence suggests that the production of cow’s milk is harmful for the environment.