A cohort of scientists, who’ve won the support of Big Meat, are inching their way towards convincing governments and international climate organizations to adopt a new scientific metric known as GWP* (pronounced “G-W-P star”), which they contend is a more accurate way to calculate methane emissions. However, that movement is alarming activists, who argue it will hand some of Earth’s top polluters a get-out-of-jail-free card.
Agriculture emits more methane—long declared to be “carbon dioxide on steroids”—than any sector, because ruminants (cows and the like) belch it out in large quantities. Methane traps heat better than CO2. But it also dissipates faster from the atmosphere; it has a half-life of 12 years, roughly. Meanwhile, as climate scientists are fond of putting it, “carbon is forever.” The UN’s Intergovernmental Panel on Climate Change (IPCC) states CO2 can linger for up to 200 years, while NASA says it’s more like 1,000 years. Zeke Hausfather, a contributing author to the IPCC’s latest assessment report, recently argued in the New York Times: “Around 20 percent of the carbon dioxide we put into the atmosphere today will still be in the atmosphere many thousands of years from now,” meaning that to undo emissions, “the carbon we take out of the atmosphere needs to stay out.”
However, because of methane’s ability to trap heat, many climate activists have started targeting their remediation efforts on it. (It’s “a crucial opportunity in the climate fight,” declares the Environmental Defense Fund.) Mitigation strategies, of course, begin with accurately assessing methane’s impact, or warming potential. In the past, a metric known as GWP100—short for, basically, global warming potential over a 100-year period—was the most widely used for this.
However, this was never without some debate in academia over what level of gas is acceptable in the atmosphere. Lately, the livestock industry has leveraged that dissension to lobby for a new measure, GWP*, that zeroes in on relative changes in emissions, not absolute numbers.
Stars as a secret sauce
The industry’s top lobbying group, the National Cattlemen’s Beef Association (NCBA), has run a duo of campaigns in tandem. One targets policymakers: It has publicly urged the Biden administration to adopt GWP* as a “more appropriate measure of methane’s actual effect on the climate,” pausing in these requests to tout the cattle industry’s “record of continual innovation to improve environmental outcomes,” and insisting that the government can help “writ[e] the next chapter in that history of stewardship” by adopting GWP* (a chapter, it made sure to note, that should be “voluntary” and “industry-led”). Among its own, the NCBA has bluntly referred to GWP* as the secret policy sauce “for us to be successful.”
The second campaign concerns meat’s public image: “Beef is being painted as a villain that can be minimized and/or eliminated to help solve global climate issues,” is how NCBA president Jerry Bohn phrased it in a 2021 op-ed. He suggested that claims that “livestock’s contribution to climate change is immense” amount to one part of the disinformation being pushed by the plant-based protein crowd.
As the meat lobby’s momentum grows, climate groups are working to counter it. Last Friday, the U.K.-based Changing Markets Foundation published a report—likely the first—designed to persuade outsiders that this obscure scientific dispute matters. It argues adopting GWP* could have a negative effect on “climate policies, equity, and the transformation of the food system,” and urges policymakers to “resist lobbying attempts by the meat and dairy industry.”
“Our strategy is to bring this incomprehensible science into the open and explain what its implications would be,” Changing Markets CEO Nusa Urbancic tells Fast Company.
No clear-cut answers
This debate has raged for a number of years in academic quarters, and the absence of a clear-cut scientific consensus, paired with the subject matter’s general inaccessibility, is why Urbancic’s group believes the meat industry is finding success as it lobbies for a substitute metric. “We already see a coordinated push in some countries,” she argues, and categorizes the pitch as “not so much about the science, but . . . the possibility for high meat and dairy producers to get off the hook.”
The IPCC introduced the global warming potential climate-modeling concept back in 1990. Since then, other timeframe-focused metrics, such as GWP50 and GWP20, have emerged. But even that first year, the UN panel wrote: “There is no universally accepted methodology for combining all the relevant factors into a single global warming potential for greenhouse gas emissions.”
Its latest report, from 2023, again notes that GWP100 is “just one potential climate impact indicator.” it says that depending on the specific time range or aspect of climate change being studied, “other indicators may be equally justified yet give a different answer as to whether a specific intervention has an overall positive or negative impact.”
GWP* was developed in 2016 by Oxford researchers Myles Allen and Michelle Cain, who criticized that GWP100 measures methane as if it’s CO2, when “it isn’t,” Allen recently said during a speech pushing the new metric in Australia. There are “big differences in the way the gases behave,” he told the gathering of government and livestock industry officials. There’s no debate that methane is 28 times more potent, but GWP100 fails to account for the fact that it also gets destroyed much faster from the air.
UC Davis CLEAR Center director Frank Mitloehner—another colleague of Allen’s who is among GWP*’s most vocal proponents—has argued throughout his career that biogenic methane (the type produced by livestock) should be measured as merely one natural step in Earth’s carbon cycle, “recycling” the CO2 that was already in the atmosphere. Fossil fuels, on the other hand, require CO2 that was buried underground, releasing new carbon into the air.
This argument holds that if a farm maintained the same number of cows for methane’s entire 12-year lifespan, it would not contribute any new global warming. A large producer could use the methane produced today by its giant livestock herd as the GWP* baseline for assessing future emissions changes. The baseline could be quite high, but if it remains stable, that qualifies as being neutral. Or say the herd shrank slightly, causing emissions to fall—that would yield a negative (“cooling”) score.
Mitloehner told Fast Company by email that the IPCC has itself written that “GWP100 overstates the warming impact of constant sources by a factor of 4.” “What I take exception to is the notion that I promote this new metric ‘because I am too close to industry’ and it gets them out of jail free,” he added. “I am promoting it because it describes what this really important and potent [greenhouse gas] does to actual warming.”
Changing Markets argues that Mitloehner and Oxford scientists are ignoring how this metric could provide cover for Big Ag at the same time that they’re busy delivering the same pro-GWP* talking points to targeted groups—from government officials to major industry players—in places like the U.S., England, Australia, and New Zealand. (For what it’s worth, Changing Markets isn’t a big GWP100 booster either: Its report endorses GWP20, the metric New York just switched to, which sticks to heat absorbed over a 20-year period, overlapping better with methane’s lifespan. The GWP20 metric “closely matches the actual warming effect of a pulse emission of methane,” the group contends, echoing other climate organizations. It’s worth noting that GWP100 scores methane’s warming potential at 34 times higher than CO2’s, but GWP20 puts it at 80. Unsurprisingly, the livestock industry also doesn’t like GWP20.)
At the end of Changing Markets’ report is a snapshot of hypothetical “official” emissions in a GWP* world. Methane’s purported environmental impacts can be “radically altered” by adjusting simple parameters, the group claims. By moving the baseline year forward or backward, an identical volume of methane emissions can swing between “causing warming, no warming, or even cooling.” Major methane emitters could use it “to justify continuing business as usual,” Changing Markets argues, and the report gives stark illustrations of how.
Last year, a different report by Changing Markets tabulated Big Agriculture’s methane emissions. (Companies rarely release this number by themselves; the organization worked with the Institute for Agriculture and Trade Policy to crunch numbers.) Using that prior report’s data, the group estimates that in one year, Tyson Foods emits the CO2 equivalent of about 80 million metric tons of heat-trapping methane, roughly the amount produced by all of Russia’s livestock combined. With a few parameters in place, the report claims Tyson could simply cut methane emissions by 1.4%, then claim its business practices aren’t contributing to global warming anymore under GWP*.
Next, the report pegs Fonterra, the world’s biggest dairy exporter, as emitting the CO2 equivalent of 30 million metric tons of methane annually—the output of Ireland’s entire animal agriculture industry. In a hypothetical where Fonterra reduced emissions by 30% by the year 2030, the rate backed by climate scientists including Allen and Mitloehner, Changing Markets’ paper says that GWP* would show Fonterra is removing 19 million metric tons of CO2 equivalent from the atmosphere, while GWP100’s calculations would score the same behavior as emitting 21.6 million. Under GWP* Fonterra could publicly claim, defensibly, to be climate-neutral if total emissions dropped even by 1.7%.
“Our calculations show how meat and dairy companies like Tyson Foods and Fonterra could escape virtually all climate responsibility if GWP* is given the green light,” reads the report, arguing the measure equips factory farms to “present themselves as part of the solution, while hiding emissions equivalent to those of entire countries.”
Whole nations can do this, too. The paper creates a hypothetical using New Zealand—a country where 44% of emissions come from livestock, and also Fonterra’s home base. By swapping GWP100 for GWP* under a 30% reduction rate, New Zealand could switch its methane emissions from 30 million metric tons a year to negative 1 million, even though it’s just “less warming from an already high level,” Changing Markets argues.
GWP* creator Myles Allen has told the livestock community his metric isn’t a carte blanche for more pollution as usual, urging producers to “read past the comma”—an opaque reference to IPCC’s line about methane’s warming impact being exaggerated by four, admonishing them to put things in fuller context. Meanwhile, Mitloehner acknowledges that “GWP* has a built-in bias toward any level producer, even if that production is huge,” and granted that this particular issue of fairness “needs to be addressed.” He stresses that he favors “aggressive reductions of emissions from Ag,” and tells Fast Company that GWP* is “not greenwashing or using creative accounting to make problems for farmers to go away” and “they must do their work like other sectors do.”
He didn’t answer directly when asked if he agreed that Big Ag—a group with well-established ties to climate inaction—might find less incentive to do more work under an accounting system like GWP*. But the physics of methane aren’t changing in the meantime, and Mitloehner said this means “we can’t afford to wait to make reductions in our emissions while we debate the fairness of GWP*.”