Livestock can be a solution to climate change, says researcher

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In the first week of May, Frank Mitloehner came to Brazil to participate in a forum on methane promoted by JBS. The researcher from the University of California – who on social media calls himself a guru of greenhouse gases – made the first presentation of the event and had no difficulty in holding the attention of the audience full of agro representatives. The title of his talk was “We don’t need to eliminate livestock to stop global warming.”

Mitloehner’s argument is that methane — the gas emitted by the belching of an ox — has a shorter lifespan in the atmosphere and its molecules are destroyed in little more than a decade, while CO2 does not.

In an interview with Sheetthe researcher did not deny that livestock is one of the causes of climate change, but defended that the greatest villains are fossil fuels.

The “guru” actually sees a dual potential for methane. According to him, reducing emissions would cause a relevant drop in the level of gases in the atmosphere, since the molecules released ten years ago would also be destroyed.

Mitloehner uses the metaphor of the bathtub. By reasoning, it would not be necessary to “turn off the faucet” on emissions to reduce the level of global warming, but to ensure that there is more methane “going down the drain” than entering the atmosphere.

“We can make agriculture part of a climate solution and this is not greenwashing talk,” he says.For Brazil, there is a real opportunity.”

You say you don’t have to eliminate livestock to face climate change. What does that mean? Livestock is often described as one of the main sources of greenhouse gases that cause climate change. It is true that livestock is a source of these gases, but they are by far more present in the fossil fuel sectors that include transport, production and energy use.

In the United States, these sectors generate 80% of greenhouse gases, with all animals together generating 4%.

While CO2 is not as potent at trapping the sun’s heat as methane, it has a lifespan of 1,000 years. Every time you’ve driven a car in your life, you’ve put CO2 in the air — and it’s all still there.

In the case of methane it is different. Methane is a potent greenhouse gas, it has a strong impact per molecule, but it is not only produced, it is also destroyed by a chemical process in the atmosphere called oxidation. These are molecules that destroy methane, and this usually happens within a decade.

Because of the fact that methane is potent on the one hand, but also short-lived, I call it “Fast and Furious” gas.

What really matters is that methane offers a real opportunity for an immediate reduction in warming. When we reduce emissions, we immediately reduce warming. The same is not true for CO2: when we reduce it, we only slow down the warming.

But, following this reasoning, shouldn’t we then attack methane first instead of CO2? No, because we’re running out of time. We don’t have time to do one thing first and then the other. The elephant in the room is the fossil fuel and related CO2.

That doesn’t mean we can relax on other sources, like methane from livestock. We need to do this concurrently.

Recently, at COP26, a commitment on methane was signed by more than 100 countries. They agreed to reduce emissions by 30% each. However, even if 100 countries reach the target, this would reduce warming by an additional 0.1°C.

Methane reductions will have an impact, but that impact will not get us where we need to be. We need to aggressively reduce—and then eliminate—the use of fossil fuels.

You have already said that methane is a flow gas and not a stock gas. What’s the difference? CO2 builds up in the atmosphere every time we burn fossil fuel. We add new carbon to the existing stock from the day before, the week before, the month before, the year before, the decade before. That’s what we call stock gas.

Currently, methane is treated in public policies as if it were a stock gas. But this is not true, because methane is not only produced but also destroyed at almost equal rates around the world.

If a cow burps today, an almost equal amount of methane that was emitted 10 years ago is also destroyed. Therefore, there is no addition of methane and increased heating.

That doesn’t mean methane doesn’t matter. We don’t want to see increases in livestock, which would lead to increasing amounts of methane in the atmosphere and cause further warming.

I like to use an analogy. Imagine a bathtub that has only one faucet but no drain. Whether we turn on the faucet on low, medium or high flow, the result will always be increased water levels. That’s what happens with CO2. No matter how much fossil fuel we burn, it always leads to rising levels of carbon.

The second bathtub is the methane one, where there is a faucet and a drain, which is always open. The drain, of course, is the analogy for methane destruction.

If you turn on the faucet normally, an equal amount of water that comes in is also drained out. As a result, water levels will remain stable. If you turn the faucet, you put in less water and that means the levels are going to go down, and that’s the real opportunity we have for methane.

If we reduce the methane, we reduce the heating. And in livestock we can do that through food additives, manure management, carbon capture and other things.

Wouldn’t forests and trees be the drain on the CO2 bathtub? Yes, and that is an excellent question. There are sinks for CO2, like forests and oceans, but they are the natural backdrop. They always reduce a similar amount. Don’t change.

What is more important is when I say that there is no atmospheric removal of CO2. The CO2 molecule is not destroyed. The methane molecule is literally destroyed.

Brazil has a emissions profile very different from the US. A third comes from agriculture and livestock, mainly enteric fermentation, and if we factor deforestation into the account, more than 70% of emissions are linked to agriculture. How do you see this scenario and how could we reduce these emissions? First of all, I can’t confirm the numbers because I haven’t studied them. So I’ll take your word. The way I look at it is that, first of all, you are still an emerging economy. Brazil is not like the United States or the United Kingdom, even though it is a strong country.

The lower a country’s development, the more important the agricultural sector is in the emissions profile. A country like Paraguay has twice as many livestock as people and few industries. A country like Ethiopia has drastically more livestock than people and virtually no major industry.

In some countries, greenhouse gases from livestock reach 90%. That doesn’t mean their livestock are terrible at emissions, it just means that the other sectors are relatively less developed.

What is really important for the Brazilian case is that, given that methane is the biggest culprit in agricultural emissions, you have a significant opportunity. If Brazil reduces methane, preferably aggressively, it is immediately taking carbon out of the atmosphere, and that reduces warming.

If agricultural industries take it seriously, these methane reductions will generate negative warming. If the country cuts methane by 20 or 30%, it will not only be able to offset other agricultural emissions, but eventually reach a point of climate neutrality where these industries no longer cause additional warming. For Brazil, there is a real opportunity.

California has achieved a big reduction in methane emissions recently. How was this possible? We have a new law in California that requires a 40% reduction in methane by 2030. At first, our farmers thought this would never be possible, until they discovered the financial incentives for reductions. Policymakers partnered with the dairy industry to put covers on waste storage on farms.

Imagine a large pond where manure is stored. This used to be open and the gases were released into the air. Now they are covered and the gases are captured. Then this biogas is converted into transport fuels, which fuel trucks, buses and so on.

In doing so, we are reducing emissions from the dairy industry and preventing trucks and buses from burning fossil diesel. It’s what we call a double whammy.

The state of California pays those who embark on this path with low-carbon fuel credits. They can amount to almost half the amount a farm receives from selling milk.

It all started about four years ago. So far, the California dairy industry has reduced 25% of its methane. That’s amazing considering the short time.

That’s why I’m so optimistic, so excited about methane reductions. I know they are possible, and when we do, we will have a short-term impact on the climate.

We can make agriculture part of a climate solution and this is not greenwashing talk. It is reality, something we must help our farmers to achieve.

Is not capturing methane as California is doing, therefore, not only a waste of energy, but a waste of money as well? Certainly. Always remember this: when you feed a cow, about 10% of the energy you give it is lost as methane. This is the same as living in a cold climate and leaving windows and doors open in winter.

This is currently what we do with our cattle. We are letting methane escape and looking at it as a problem when we should be looking at it as an opportunity.


X-RAY

Frank Mitloehner, 53

He is a professor and air quality expert in the department of animal science at the University of California at Davis. Born in Germany, he moved to the United States 25 years ago and is currently also the director of the Clear Center, a center that studies the sustainability of animal agriculture.

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