The Role of Dairy in Global Warming

Activists advocate for the planet & Farmers defend their livelihoods: What does science say?

Global warming has transformed from rumor to fact; and now we are rushing to find a solution. Fingers have been pointed and speculation has arisen. The dairy industry has been targeted as being part of the problem, but are they really? Cows release methane into the atmosphere as a natural byproduct of their existence, and methane is one of the major greenhouse gases. So, some understandably infer that cows, the dairy industry, and livestock farming in general are the cause of global warming. On the other side of the spectrum, farmers are defending their livelihoods and trying to prove that their livestock are not the problem, or at least not the only one responsible.

To settle the dispute, we turn to science and subsequent data to shed some light on the truth of the matter.

Research

UCDavis published a paper “Methane, Cows, and Climate: California Dairy’s Path to Climate Neutrality” where they addressed methane production and effect on the environment.

1.Methane

Methane is a greenhouse gas (GHG) that comes in second to Carbon dioxide in important GHGs. It contributed 9% of 2016 total emissions in California. Ruminant livestock, in particular, the dairy sector contributed 45 % of all methane state emissions in 2013 data, split between dairy manure & dairy enteric (digestion). Dairy cow methane emissions are biogenic or natural.

“Carbon is converted into carbohydrates in the plant, which are then consumed by the cows, digested, and released from the cows as methane. After about 12 years in the atmosphere, that methane is oxidized and converted into CO2…The carbon originally utilized by the plant is returned to the atmosphere, contributing no net gain of CO2”

2.Carbon Dioxide

CO2 is the primary GHG causing global warming. Total CA emissions in 2016 were 83% CO2. This carbon will remain in the environment for hundreds of years effecting the climate. Fossil fuel methane is converted to CO2 when we burn natural gas. CO2 is a stock gas that accumulates over time vs. Methane is a flow gas that is destroyed at the same rate of emission.

3. Dairy’s Place in the Issue

“The U.S. dairy sector accounts for 2 percent of the nation’s total GHG emissions”

Dairy may not contribute to global warming as significantly as previously thought; however, they still have an impact. The research suggests that reducing methane emissions can lead to a fast drop in atmosphere concentrations of GHGs because of its short lifespan — having a climate cooling effect that can offset the warming by CO2 emissions.

California’s changes in their dairy industry reduced their methane emissions by managing the number of milk cows in the state and no longer expanding production — fewer cows producing methane, while methane is still being removed from the atmosphere naturally.

They are also installing equipment designed to capture or reduce emissions incentivized by state funds. 20% of GHGs produced by the dairy sector are created by farm equipment. Electrification of systems and use of solar energy has decreased fossil fuel use per unit of milk by 58.5%.

“Attaining California’s level of production efficiency in all global dairy production regions could reduce total global GHG emissions by as much as 1.73 percent.”

What This Means

Farmers and environmental advocates used their passion for their livelihoods and environment to research & drive science to come up with the data to reveal the real problems behind global warming and find solutions that both parties can implement. Dairy impacts global warming for sure, but they are not by far the only ones responsible. We contribute to global warming in our burning of fossil fuels in transportation, iron & steel production, waste landfills, and manufacturing to name a few.

Sources:

Mitloehner F., Kebreab E., & M. Boccadoro, Methane, cows, and climate change: California dairy’s path to climate neutrality. UCDavis CLEAR Center. September 2, 2020.