“If you were to make it to Los Angeles [right now] you would see beautiful blue skies,” said Dr. Frank Mitloehner, during the June 4 episode of The Dairy Signal presented by Professional Dairy Producers (PDPW).
A professor and air quality extension specialist with the department of animal science at the University of California – Davis, Mitloehner said, “You can go to many of the places that have had such problems with smog over the years, and at the height of COVID-19 in China, Beijing was crystal blue. It was wonderful to see the blue skies over Beijing, Shanghai, Guangzhou, Wuhan, all of these major cities.
“Unfortunately, the second the lockdowns were lifted, everything went back to normal,” he said, noting the same thing will happen in the U.S.
Therefore, there will be no long-lasting environmental effect, but there may be a psychological one.
“What COVID-19 has done is: It has shown people where pollution really comes from. ... It comes from the use of fossil fuel, and everything that burns fossil fuels, and putting those resulting emissions into the air,” Mitloehner said.
As the smog disappeared this spring, so did society’s overall concern about climate change. This, too, will return as the world reopens.
Meanwhile, the U.S. dairy industry has an opportunity here to clear up previous misconceptions about climate change and also to lead the efforts in climate cooling.
Greenhouse gases emitted from livestock are different than those from burning fossil fuels. Fossil fuels, such as oil, coal and gas, are carbon that was contained in the ground for a very long time. When burned, it becomes atmospheric carbon dioxide (CO2).
“Every time you’ve ever driven your car, you put CO2 in the atmosphere, and all of that is still there,” Mitloehner said.
“It’s called a stock gas because you always add additional gas to the existing stock. That’s why CO2 is such a problem, because it has a thousand-year lifespan; nothing destroys it.”
Plants do use atmospheric CO2 to grow, and that carbon becomes cellulose and other carbohydrates in the plants. Cows ingest the carbon-filled plant material and emit it as biogenic methane by belching, flatulence or manure production.
The lifespan of methane is 10 years, much shorter than other greenhouse gases. It is also destroyed by oxidation, a natural process in the atmosphere that converts it to CO2 again.
“Methane is a flow gas. It’s produced and destroyed at equal rates,” he said.
This is the biogenic carbon cycle. If you have constant livestock herds, you’re not endlessly increasing methane because it is equal to the amount of methane destroyed.
“That’s great news, because in the United States, we have not increased herd sizes. In fact, we have decreased herd sizes over the years,” Mitloehner said.
Adding to that, farms are finding ways to actively reduce methane with anaerobic digesters and feed additives. If methane is still destroyed at the same rate, but produced at a lesser rate, it results in a net cooling effect.
“That reduction of methane induces cooling; it counteracts global warming caused by fossil fuels,” he said.
“In other words, what I’m telling you here is that our dairymen have the potential of being viewed as a solution to the climate issue.”
This can be accomplished in a few different ways.
First, Mitloehner said there are new ways to calculate the warming impact of methane. Once adopted nationally and internationally, it could drastically change the carbon-footprint discussion, especially in relation to livestock’s contribution.
Second, scientific research continues to explore ways to reduce methane. “That has already had massive impacts in California. We have reduced methane by 25% over the last few years,” Mitloehner said.
“Our dairy industry is on a path to climate neutrality, counteracting some of the nitrous oxide and other greenhouse gases with methane, which we are learning to reduce effectively,” he said. “I think this is something you can expect to happen in Wisconsin and other places.”
Third, financial incentives are furthering methane reduction on farms.
“We are now experiencing a new gold rush in the state, because the state incentivizes financially the construction of anaerobic digesters,” he said.
These are primarily in the form of covered lagoons that trap the biogas and use it to produce renewable natural gas (RNG), which is sold to replace diesel in fleet vehicles.
This was accomplished by the dairy industry acknowledging its contributions to climate change and agreeing to work with the state, which, in turn, offers financial incentives to reduce methane.
“We have shown that reductions are possible, and we have engaged on making them work,” Mitloehner said. “That is much more than any other sector of society can show.”
The market in California is so large that people in other states are able to sell into it. These financial incentives have helped farms across the U.S. to build systems that capture biogas and convert it to RNG.
Since the world’s transportation will not be slowed to keep skies clear long term, Mitloehner said, “The biggest change we can hope for is that we decarbonize the transportation sector and the energy sector in ways where we use more renewables.”
The dairy industry is already taking part in making that happen. 
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Karen Lee
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- Progressive Dairy
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