Scientists with the world’s top climate organization made reducing meat consumption an official policy recommendation in 2019, echoing what environmentalists had urged for years: Eating less meat, in particular beef, reduces the large volume of emissions attributed to livestock. That guidance has only accelerated efforts by the beef industry to discredit the notion that strip steaks and cheeseburgers are climate culprits.

For two years, industry officials and a handful of sympathetic academics, some of whom are funded by livestock business groups, have argued in congressional testimony, newspaper op-eds, and research papers that the climate science is all wrong. There’s even alternative math to prove the cattle industry has been falsely maligned.

The industry doesn’t dispute that livestock generate huge quantities of methane, a potent greenhouse gas with more than 80 times the short-term warming impact of carbon dioxide. Even so, the National Cattlemen’s Beef Association, a trade group representing more than 175,000 cattle producers, argues that American cattle “may not be contributing much at all to global warming.”

“Beef is being painted as a villain,” wrote Jerry Bohn, head of the NCBA, in a 2021 op-ed for an industry trade magazine. Assertions against beef are an “outrageous lie,” he added, pushed by those seeking to sell fake-meat alternatives.

Jason Sawyer, an associate professor and research scientist with King Ranch Institute for Ranch Management at Texas A&M University, is being paid by the NCBA to study the industry’s climate accounting. He says it’s possible the U.S. beef industry has actually had zero impact on climate change since 1986. There’s even a chance, he says, that American beef may have reduced the planet’s warming.

When it comes to the worrisome buildup of methane in the atmosphere, Sawyer says, “a source like U.S. beef cattle is a really, really, really small piece.”

Mainstream climate science has long presented a much more grim arithmetic. Cows burp out large quantities of heat-trapping methane. As a result, beef causes vastly more emissions than most other foods – more than five times as much as an equivalent amount of chicken or pork and at least 15 times more than lentils and other plant-based proteins, according to data from the University of Michigan.

In the U.S., where more than 800,000 ranches, farms, and feedyards raise some 80 million head of cattle each year, the beef industry generates about 243 million tons of heat-trapping gases annually – equivalent to all the climate pollution from the Netherlands and Finland combined.

To avert the worst warming impacts, McKinsey & Co. estimates each person on Earth, on average, will need to cut by over half the percentage of protein they’re projected to get from ruminant animals (mainly beef) by 2050. That’s particularly jolting for the typical American, who eats 58 pounds of beef each year, roughly four times the global average.

To challenge this forbidding math, Sawyer and other pro-beef academics are making hotly contested assumptions, backed by a new method for counting methane emissions that concerns many climate scientists. This accounting metric, known as GWP*, was developed by Oxford researchers in 2018 to more accurately predict how changes in methane emissions affect global temperatures.

Cattle groups are now applying this metric to their herds to claim a vastly reduced climate impact. GWP* focuses on changes in methane emissions, penalizing new or growing sources and putting less blame on large, steady emitters, like cattle herds in well-to-do countries. “It’s the industry choosing metrics which make their impact look small,” says Drew Shindell, professor of Earth science at Duke University. “It’s not a credible way to approach the problem.”

Some scientists worry that the beef industry’s efforts to recalculate its climate footprint will cloud a simple truth: All methane causes warming. And with almost three times as much of it in the atmosphere as in the preindustrial era, all major methane sources need to be urgently curtailed.

“It doesn’t matter which way you dress it up,” says Pete Smith, professor of soils and global change at the University of Aberdeen in Scotland. “It’s an incontrovertible fact that more methane in the atmosphere means more climate warming, so we need to reduce it.”

When cattle ranchers are asked about climate change, conversations often become tense. And not infrequently they end up invoking the work of a prominent scientist at the University of California at Davis.

“You’ll want to talk to Frank Mitloehner about what you just said,” says Lyle Perman, who raises more than 500 cows at Rock Hills Ranch in South Dakota, when asked about cattle’s effects on climate. “We’re not saying we don’t contribute to climate change, but we take issue with some of these characterizations.”

Mitloehner, a professor in the department of animal science, has emerged as an industry darling after a decade-plus of outspoken challenges to those who say eating less meat will help protect the climate. “Farmers are criticized and demonized by much of society,” he says.

Mitloehner speaks with a patient cadence and seems to relish technical terms – “hydroxyl oxidation” – which he pauses to repeat for his audiences. Although he’s not a climate scientist, Mitloehner sports the handle @GHGGuru on Twitter and describes livestock farming in the U.S. as just a drop in the bucket of the world’s greenhouse-gas emissions.

“To suggest that what you eat, whether you eat a burger this week or not … will have a huge difference on the climate is irresponsible,” said Mitloehner in an April YouTube interview that has garnered 2.8 million views. “It’s a smokescreen deflecting off the 800-pound gorilla.”

Mitloehner first gained prominence when he challenged an influential 2006 United Nations report that found that livestock accounted for an astounding 18 percent of worldwide heat-trapping emissions. While that was accurate at the time (more recent inventories have pegged it at 14.5 percent), the report also concluded that livestock’s emissions eclipsed those from transportation. Mitloehner correctly pointed out that this was misleading: The U.N. report had calculated the entire life cycle of livestock emissions – including the fertilizer used to grow crops to feed animals – without doing the same for the supply chain behind vehicles.

But Mitloehner has sparked the ire of many scientists by frequently downplaying the climate benefits of eating less meat. Even if every American went vegan, he often says in speeches, it would reduce U.S. emissions by only 2.6 percent. “It’s staggering how many people continue to think that merely giving up meat – even once a week – will make a significant impact on their individual carbon footprints,” he said in testimony to the U.S. Senate in 2019.

Cattle occupy a feedlot in Columbus, Neb. A recent study from the University of Michigan found that if Americans cut their consumption of animal products by half, it would lead to a 3.4 percent reduction from today’s emissions levels. Nati Harnik/Associated Press

That 2.6 percent comes from a study that was criticized for assuming there would be even more acres of corn and soy, requiring carbon-intensive fertilizer. Since the biggest market for those crops is feeding livestock, it’s not clear what level of demand would exist without chickens, cattle, and pigs.

A more recent study from the University of Michigan found a heftier impact: If Americans cut their consumption of animal products by half, it would lead to a 3.4 percent reduction from today’s emissions levels. “There’s just no way to meet our climate goals without dramatically reducing our beef consumption,” says Jillian Fry, an assistant professor of health sciences at Towson University, who has criticized Mitloehner’s work in the past for downplaying the climate impacts of livestock farming.

Mitloehner calls the criticisms “confounding.” He says he agrees animal agriculture has an impact on the climate and it should do its part to reduce its footprint. “I’ve dedicated my professional life to helping it do just that,” says Mitloehner, who gets about 40 percent of his outside research funding from companies and groups connected to the agriculture industry. But he warns of placing “unproportional blame” on animal agriculture and insists that reducing consumption of animal protein won’t result in a “major benefit” for the climate.

That point, however, doesn’t stand up well to scrutiny. The U.S. is such a huge emitter of greenhouse gases, cutting even just 2.6 percent of the country’s emissions would be the same as eliminating the entire combined climate footprints of Portugal, Sweden, and Switzerland. When asked about this, Mitloehner says, “It’s not the game changer that we need.”

As the beef industry has challenged the math showing it’s an outsize climate polluter, Mitloehner, Texas A&M’s Sawyer, and other researchers have pursued a new argument: Climate scientists might be badly shortchanging cattle ranchers by not crediting them for the large quantities of carbon dioxide soaked up by soils beneath their grasslands and pastures. “Why nobody reports upon that, I don’t understand,” Mitloehner said in a speech last year.

Industry officials have taken the argument even further. Riley Robbins, president of the Kansas Cattlemen’s Association, told the Wichita Eagle in June that cattle are “almost always carbon-negative,” when you count the carbon soaked up by their land.

Although it’s true that some grasslands can be better managed to soak up more carbon, climate scientists say most such acreage exists in a state of equilibrium, where large amounts of carbon have already been stored and the volume of carbon dioxide exiting is roughly equivalent to the CO2 being absorbed. Overall, the potential gains from grasslands sequestration “is not going to have that much impact” on the beef industry’s climate footprint, says Alan Rotz, an agricultural engineer with the U.S. Department of Agriculture who worked with the cattle industry in 2019 to quantify its emissions.

Perhaps the industry’s most audacious move has been to rethink the intricacies of methane accounting. It hinges on a basic flaw in the way methane has been counted for decades. Methane is far more potent a greenhouse gas than CO2, but it disappears from the atmosphere quickly – in about a decade, compared with hundreds or thousands of years for CO2. These differences have made it vexing to measure methane’s impact alongside that of the predominant greenhouse gas. The UN and climate-accounting bodies have settled on a 100-year comparison, a timescale that makes methane about 28 times more potent than CO2.

But this 100-year metric, known among scientists as GWP100, fails to capture an important point. Because of carbon dioxide’s long life, every ton emitted increases the amount of the gas accumulating in the atmosphere. During 2020, when much of the globe was in lockdown, emissions fell, yet concentrations of CO2 increased. Since methane breaks down more quickly, it doesn’t accumulate in the same way. It takes only a modest cut in methane emissions for its atmospheric concentration to shrink – and warming to subside. This key difference is missed by today’s climate accounting.

To help policymakers better understand this when thinking through climate legislation, researchers from Oxford developed GWP* to quantify how a change in methane could affect temperatures.

The beef industry quickly embraced it, because applying GWP* to an individual industry in a single country can generate rosy climate numbers if that source of methane is relatively stable. For the U.S. beef industry, with a cattle population roughly the same size as it was in the 1960s, this new metric cuts its climate footprint in half, according to Sawyer, who says he’s planning to publish his analysis in a peer-reviewed journal. “I get accused of trying to greenwash or minimize the problem,” he says. “But we don’t want to solve the wrong problem. I don’t want to take food out of someone’s mouth when I didn’t have to.”

Many scientists criticize this approach. First, the planet has already warmed to a dangerous level, thanks in part to a near-tripling of methane in the atmosphere during the past 250 years. The U.S. cattle herd has contributed to this, growing more than twentyfold during that time, according to estimates from Kees Klein Goldewijk, a researcher at Utrecht University in the Netherlands. Just because the American cattle herd hasn’t grown in recent decades doesn’t mean it hasn’t contributed to the increase of methane in the atmosphere.

Second, there’s the question of fairness. Under GWP*, the 80 million-cattle herd in the U.S. counts little toward increased warming because of its stable size. But a far smaller herd in a country like Ethiopia gets blamed for increasing atmospheric methane – and the accompanying warming – simply because its cattle population is growing.

“It sets up an unethical logic,” says Joeri Rogelj, a climate researcher at Imperial College London. “Because you polluted more in the past, you’re allowed those emissions in the future. That is fundamentally unfair.”

All of this obscures what Andy Reisinger, a climate researcher at Australian National University and an official with the New Zealand Ministry for Environment, says is a pretty simple point: Global methane emissions are skyrocketing, and they need to come down immediately.

“If you ask the question, ‘Are my emissions today causing damage?’ The answer to that is always, unambiguously yes,” Reisinger says. “Because every amount of greenhouse gas, no matter which gas we emit, makes the Earth warmer.”

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