Written by: Sarah Novak | April 1, 2021
I grew up in Wisconsin and as a child, vacation meant going to my grandparents’ dairy farm in Prairie du Chien to help bale (really stack) hay or feed calves. The summer after my freshman year of college, I woke up at 4:30 a.m. to drive 30 minutes to work on a dairy farm – for free! So, my love for dairy farms, dairy cows and milk, cheese and ice cream runs deep. When I saw the article, “Removal of dairy cows may reduce essential nutrient supply with little effect on greenhouse gas emission,” I knew I had to read it.
You’ve seen the false headlines: if we just eliminate meat, milk and egg consumption, we could save the planet. Some claim that we can simply grow more nuts, veggies and fruits on the land that is currently used for livestock and poultry production and we can make a big environmental impact. Well, I’m glad Drs. Liebe, Hall and White took the time to research this theory.
They modeled three different scenarios – depopulation (i.e., remove all U.S. dairy cows immediately), current management (i.e., keep the number of cows in the U.S., but export 100% of the milk) and retirement (i.e., the cows would be “retired” to a pasture-based system but the country would reduce the numbers that could be supported by available pastureland). They looked at the impact these scenarios would have on land use, greenhouse gas (GHG) emissions and nutrient availability for people.
Today, the U.S. dairy industry contributes about 1.58% of the total U.S. GHG emissions. For reference, according to the U.S. Environmental Protection Agency, agriculture accounts for 9.9% of the GHG emissions in the country; and dairy is responsible for 16% of the total agricultural emissions, so 1.58% of the total U.S. GHG emissions.
Dairy also supplies the protein requirements of 169 million people, the calcium requirements of 254 million people and the energy requirements of 71.2 million people. In addition, dairy foods are a valuable source of vitamins A, D, B12, riboflavin and choline for people. So, making a change to eliminate dairy cows wouldn’t just impact GHG emissions – it would impact how we feed people. Also, eliminating dairy production impacts fertilizer sourcing (since manure is used as fertilizer) and deposition of by-product feeds (i.e., the use of products like citrus pulp or corn gluten feed).
As expected, the researchers found that GHG emissions were unchanged in a current management scenario of exporting dairy, but resulted in decreased nutrient availability for U.S. consumers. In the retirement scenario, GHG emissions declined 11.97% and all 39 nutrients considered in human diets decreased. In the depopulation scenario, GHG emissions declined 7.2%, although 30 of the 39 nutrients increased, several of the essential nutrients declined.
The overall results of the study suggest that the removal of dairy cows in the United States would only reduce GHG emissions by 0.7% and would decrease the available supply of essential nutrients for the human population.
Tonight at dinner, I won’t feel bad about having a glass of milk, adding cheese and sour cream on my tacos, and walking to get ice cream at the local ice cream parlor with my kids because I know dairy is a sustainable source of vital nutrition.