Revised analyses have shown the U.S. livestock industry is more efficient than the U.N. report previously indicated. The EPA reports that livestock production emits 3.4 percent of GHG in the U.S., compared to 26 percent from transportation.
But given the environmental criticism the livestock industry receives on emissions, beef industry leaders are pushing harder to find where more progress can be made.
The USDA Agricultural Research Service (ARS), the National Cattlemen’s Beef Association (NCBA) and the University of Arkansas joined forces over the past several years to study the environmental impact of beef.
Alan Rotz, an agricultural engineer with ARS and adjunct professor at Penn State University, introduced the new life cycle assessment (LCA) study to media representatives at an NCBA beef sustainability symposium on Oct. 23 in Denver.
Rotz said many traditional media reports have mistakenly grasped onto carbon footprint as the lone factor being analogous to sustainability.
“It’s going away from this now, but five to 10 years ago, all they could think about was greenhouse gas, and if you had a high carbon footprint, you were unsustainable, and low carbon footprint, you were sustainable,” Rotz said. “But that was a misrepresentation of what carbon footprint was all about.”
To form a full picture, ARS, NCBA and the University of Arkansas gathered survey data from all segments of cattle production: cow-calf, dairy, stocker and feeder. About 2,300 survey responses were received and analyzed from all seven NCBA regions. Researchers visited 20 ranches and 10 feedlots in each region to observe practices and gather more data.
The data went into a Farm Gate Analysis program developed by ARS that tracked all production systems and broke data down using operation type, herd size, soils, climates and final production markers. This led to a full life cycle assessment, tracking inputs and resources used from the cradle to the gate in livestock production.
What firm answers did the LCA study want to determine? How much carbon dioxide, nitrous oxide and methane are coming from farms, ranches and feedlots, in the entire life-chain production of beef? And what is the global warming potential that comes from these emissions?
The LCA factored the following:
- Inputs such as fuel, electricity, fertilizer, pesticides and machinery were traced as upstream sources of emissions.
- Feed production, animal production and manure handling were traced as direct links and sources of emissions.
- Final products, such as milk sold, animals sold, feed sold and exported manure, were identified as emissions allocated to other farm products.
Showing vast differences by region, here’s what the study determined with four main carbon footprint categories:
Greenhouse gas
The LCA shows 17 to 27 kilograms of carbon dioxide emissions for every kilogram of beef carcass weight, making the GHG emission from producing one steer similar to that emitted by driving a pickup truck for one year, Rotz said. GHG emissions were greatest in the Southern Plains and Southeast regions.
But Rotz qualified how livestock cattle carbon dioxide emissions differ from other industries. Both cattle and transportation vehicles emit carbon dioxide. Transportation extracts fossil fuels, which emit carbon dioxide that stays in the atmosphere.
With cattle, the CO2 will become methane, and that methane has a global warming impact, Rotz said. But its duration is shortened, and methane reverts back into the cycle.
“When it comes down to it, cattle have little long-term impact on our climate,” Rotz explained, “because this is part of a natural cycle. Whereas, driving our vehicles does have a long-term impact, even though CO2 doesn’t have near as much global warming potential as methane, yet when it’s there, it’s here forever.”
Reactive nitrogen loss
Beef cattle production has a more noticeable footprint of reactive nitrogen loss, with a range of 121 to 257 grams of nitrogen lost per kilogram of beef carcass weight. On a larger scale, the amount of reactive nitrogen lost by producing a steer is the equivalent of using 215 to 450 pounds of urea.
Why is that nitrogen loss critical? While nitrogen in the atmosphere is inert and not creating a carbon footprint, reactive nitrogen is different. Industry uses the Haber-Bosch ammonia process to fixate nitrogen into fertilizer sources, “and then that reactive nitrogen transforms and moves around and ends up in many forms in the environment, and none of those forms are particularly good for the environment,” Rotz explained.
Reactive nitrogen in the atmosphere also bonds molecularly with other sources. This fertilizes areas that should not be fertilized. Loose ammonia can also compound in the atmosphere “to create very fine particles, which are antagonistic to humans.”
The battle over nitrogen loss is dormant, because the EPA has stopped looking at it under this administration. But it’s only a matter of time before that emission gains more regulatory attention.
Fossil energy use
Beef production shows less of a footprint in total fossil fuel energy used, with a range of 40 to 60 megajoules per kilogram of carcass weight produced. That’s the equivalent of about 130 gallons of diesel fuel used for every steer produced.
Energy use is fairly consistent among the regions, and is used primarily for electricity and fertilizer production, as well as fuel spent to produce feed and feed it to animals.
Non-precipitation water use
If there’s one category that shows the most variation across regions and segments of beef production, and more need for efficiency, it’s water use. The new LCA categorizes non-precipitation water, or blue water, as water piped, irrigated or extracted toward uses related to beef production.
The LCA showed a range of 200 to 5,800 liters per kilogram of carcass weight produced. That’s the water per steer equivalent of filling anywhere between 1 to 25 residential swimming pools, or 694 gallons per pound.
The number is eye-catching for its sheer volume, and its regional variability.
Some will argue the enormous amount exceeds standard production. Studies from Jude Capper of Washington State University from 1994 showed 367 gallons of water per pound of boneless beef.
But the LCA does quantify regional differences, and they reflect much higher rates of water usage in the arid Northwest and Southwest regions where irrigation is critical.
“That’s where it is, the arid West,” Rotz said. “The Ogallala Aquifer and all the water we’re pulling out of there, it’s not recharging, so it’s a problem. A lot of that water is actually going to beef production.”
Improvement in segments
Rotz said the sustainability improvements have potential in all segments and regions, but it especially stands out among cow-calf producers.
In comparing the production of a cow-calf steer to that of a dairy steer calf, the maintenance costs and footprint are much higher for the cow-calf system. And in the dairy, the calf is merely a byproduct with no measurable impact.
“It comes back to maintaining the breeding stock,” Rotz said of cow-calf systems. “A lot of this greenhouse gas emission is from keeping a cow and a bull. You maintain them for a full year, to try to get one calf per cow; that animal is out that full year, living, breathing, creating methane from the feed it is consuming.
“In the dairy farm, we have that same cow; it’s producing even more methane, because of the higher methane level. Nevertheless, most of that footprint, environmental impact of that cow, is being allocated toward the milk they’re producing and going into the milk footprint. So the calf itself is just sort of a byproduct; we’re getting it free of environmental impact.
“So when we look at some of the progress made in the past 30 to 50 years in the beef footprint, particularly in the past 15 years, we’re using a lot more culled animals from the dairy industry.” 
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David Cooper
- Managing Editor
- Progressive Cattleman
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PHOTO: Cow-calf operations in arid parts of the country have lower greenhouse gas emissions, but utilize higher volumes of water. Photo by Mike Dixon.
