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October 16, 2019

The Three Truths of Climate Change

 |  By: Dairy Talk

As I walked toward a seminar on dairy’s role in climate change at World Dairy Expo this past October, I overheard one farmer say to another: “The climate is always changing.” They both chuckled dismissively and went on to other Expo attractions.

Earlier that same week, just an hour or so north, farm fields were deluged with another four inches of rain. Grassed waterways looked like streams as the runoff poured from fields. Few farmers along the freeway from Minneapolis to Madison had even begun to cut corn silage. Most of these fields weren’t planted until late May or early June because of another wet, late spring. Fields were no where near ready to chop, and muddy soil conditions would have prevented it anyway.

There is no denying climate change is real. Frank Mitloehner, an air quality specialist and an advocate for animal agriculture at the University of California-Davis, gave a compelling presentation on climate change and the dairy industry’s role in it at Expo. In a nutshell, Mitloehner made three points. You could call them three truths:

  1. Climate change is real.
  2. Dairy plays a role, but it is not what activists say it is.
  3. It is your responsibility to tell dairy’s story.

Climate change is real. In 1750, based on ice cores and other measures, scientists estimate the carbon dioxide (CO₂) concentration in the atmosphere was 280 part per million (ppm). By 2000, that concentration had climbed to about 370 ppm, with CO₂ concentrations starting to spike drastically  upward in the 1950s following the rapid industrialization of world economies after World War II. That trend has not stopped—or even slowed.

As a result, global temperatures are rising, the atmosphere contains more moisture, and storms are becoming more frequent and more violent. Five-hundred- and one-thousand-year rain events and storms are occurring several times each decade.

Dairy plays a role. Dairy farming does play a role in this, though it’s far from what activists say it is. The U.S. Environmental Protection Agency (EPA) estimates all of agriculture contributes 9% to U.S. greenhouse gas emissions (GHGs). Animal agriculture contributes 3.9%; dairy about 2%. Transportation, electricity generation and industry produce about 80% of U.S. GHGs, most of which come from CO₂ production.

Dairy’s GHG contribution comes mainly from methane emissions. Though methane is a powerful green house gas, methane from cattle only survives about 10 years in the atmosphere. It is converted back to CO₂, through a process called photochemical oxidation, which is then used by plants for growth. “Dairy is not adding additional carbon to the atmosphere because the amount produced by cows equals the amount destroyed through hydroxylation,” he says. In other words, as long as you don’t add more cows, you don’t add more GHGs to the atmosphere.

The other point is that the more efficient cows are in converting feed to milk, the lower the GHG footprint. North American cows produce about a pound of CO₂ equivalent for every pound of milk they produce. Globally, the average is about 2.1 lb of CO₂ equivalent per pound of milk. In sub-Sahara Africa, the ratio is 7.3:1. “Critics of animal agriculture use these global numbers and apply it to the United States,” says Mitloehner.

Tell dairy’s story. Since 1950, when GHGs started to spike globally, the U.S. dairy industry has reduced the number of dairy cows by 16 million and yet is producing 60% more milk. “We have decreased our carbon footprint by two-thirds over the past 70 years,” says Mitloehner. “Isn’t that an achievement you should brag about?”

Mitloehner says farmers can no longer walk away from the climate debate. “You can’t complain no one is telling your story,” he says. “This is your legacy. You have a responsibility to tell your story.”

To arm yourself with facts and talking points, listen to Mitloehner’s presentation here:

For a shorter tutorial on dairy’s GHG cycle, listen here:


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