People who are opposed to animal agriculture have for a long time pointed their fingers at the industry for its harmful impact on the environment and have claimed that it is largely responsible for global warming.
But Frank Mitloehner, professor and cooperative extension air quality specialist at University of California-Davis Department of Animal Science, says if the critics only knew the facts, they wouldn’t be so adverse to animal agriculture.
Mitloehner spoke at the Animal Agriculture Sustainability Summit on January 28 at the 2020 International Production & Processing Expo (IPPE).
The vegan meal served recent Golden Globes ceremony shows that ignorance, Mitloehner said. While the Golden Globes organizers touted the vegan meal as a means to help the climate crisis, other behaviors shown at the ceremony, such as participants “flying in on Learjets and being shipped by limos to the venue, importing water from Iceland to drink and flowers from Italy,” were “highly irresponsible.”
The main greenhouse gasses
Mitloehner identified three key greenhouse gasses (GHGs): carbon dioxide, methane and nitrous oxide. Most of his presentation focused on the former two.
He noted that because methane is 28 times more potent in trapping in solar heat than carbon dioxide, then people think it is the most harmful to the environment. That has put a target on the back of livestock producers, but Mitloehner said that target has been unfairly placed.
When people lean that methane’s potency as a GHG is more than that of carbon dioxide, they assume that the methane left behind by cattle is a big contributor, he said. But what people may not realize or choose to gloss over is the fact that it only takes ten years for methane to be destroyed naturally, but carbon dioxide takes about 1,000 years.
The impact of carbon dioxide
While livestock produces carbon dioxide, too, the animals really only recycle it.
That is quite the contrast when compared to the carbon dioxide produced from the burning of fossil fuels for transportation and energy production.
Mitloehner said that the carbon dioxide that plants breathe comes from the atmosphere, and that carbon goes into carbohydrates set as cellulose. Cellulose can be digested by ruminant animals like cattle.
“That means they can upcycle cellulose and make that cellulose into animal source foods and as an unintended consequence, they are producing methane by belching or through manure,” Mitloehner said.
He said that methane stays in the atmosphere for a decade, and while in there it goes through a hydroxyl oxidation process, which produces methane into carbon dioxide.”
But that carbon dioxide is not new carbon dioxide, he said, but rather recycled carbon dioxide, since it initially came from the atmosphere.
However, carbon dioxide from the burning of fossil fuels that was not in the atmosphere but rather in the ground, is new carbon dioxide, he said.
“We are not adding additional CO2 into the atmosphere, unless we add additional livestock to our herds,” he said.
“Methane is still a potent greenhouse gas, but if you were to have a diary with 100 cows for 100 years, for the first ten years you added new carbon to the atmosphere, but then it remained steady.
Global cooling in livestock production
Mitloehner pointed out that when a person looks at the time from before Europeans settled in the United States, bison and antelope numbers were much more plentiful, but over time, populations of those animals shrunk while cattle numbers grew.
With that in mind, he said, methane emissions from ruminant animals has not really changed in several hundred years.
He also pointed out that livestock producers who have been in business for years can also reduce their carbon footprint, simply by reducing their herd size by small amounts. In doing so, farmers can be responsible for “global cooling.”
Mitloehner said an initiative is in place in California where the agriculture industry is actually reducing its carbon footprint while still producing the same amount of food.
With fewer, but more efficient practices and better animal genetics, that can be done and is already being done in the United States.
“We went from 25 million dairy cows to 9 million dairy cows, but we produced 60% more milk with that,” said Mitloehner. “We shrunk the carbon footprint of dairy by two-thirds.”
