Scientists outline measures to cut greenhouse gas emissions in US beef supply chain by 30%

05 Sep 2024 --- Scientists in the US have urged that the country’s beef industry can mitigate its greenhouse gas (GHG) emissions by up to 30% by implementing alternative practices during the feed production (8%), grazing (19%), confinement (3%) and processing (1%) stages.

The US is the world’s largest beef producer and fourth largest exporter, processing nearly 33 million head of cattle to produce over 12.3 million metric tons annually. The industry has a significant impact on the country’s food supplies and livelihoods, but also accounts for 3.3% of total GHG emissions in the country. This calls for improving its emission reduction initiatives, which the study’s findings can help with.

Researchers at the University of Minnesota’s Institute on the Environment and The Nature Conservancy conducted a location-specific beef industry life cycle assessment to identify emission hotspots along the supply chain from farms to beef processing plants.

“Our assessment is highly tailored, meaning we’ve developed distinct recommendations for different parts of the country,” says Rylie Pelton, PhD, University of Minnesota research scientist and lead author.

“Our recommendations focus on ways the beef industry can reduce their GHG emissions and increase the carbon sequestration in soils and working lands.”

Beef processing-related emissions are localized in the Great Plains and some emission hotspots in the northeastern and southwestern regions, states the study.The findings are published in Nature Food and describe a “spatially explicit,” fine-scale ‘cradle-to-gate’ assessment of GHG impacts and US beef supply chain mitigation opportunities.

Process and location-specific emissions

The researchers flag that the beef supply chain is one of the most intricate food production systems in the US, making it difficult for beef producers to identify where and which opportunities are most effective for reducing their emissions.

The findings indicate that the US beef industry currently emits 257.5 metric tons of CO2 eq per year, with 15% attributed to feed production, 64% to grazing, 19% to confinement and 3% to processing.

The team also assessed subregional patterns and identified hotspots where mitigation opportunities are possible for different actors along the supply chain.

“Generally, findings indicate absolute emissions from feed production associated with beef sourcing, and confinement (primarily feedlots) is concentrated in the Great Plains and Midwest regions, whereas emissions from grazing tend to be more evenly distributed across the western US,” notes the study.

Meanwhile, processing-related emissions are localized around processing facilities, with the highest densities in the Great Plains and some emission hotspots in the northeastern and southwestern regions.

Mitigation steps

The team also examined 42 alternative practices across the supply chain, including cover cropping, feed additives and energy management strategies.

The scientists say that implementing a feed additive in the feedlot could reduce feedlot emissions by 12%.The scientists outline various mitigation measures across various supply chain stages that manufacturers can implement during crop production, grazing, feedlot, dairy operations and processing.

For crop production, they encourage the use of cover crops to increase soil organic matter, nutrient management to minimize nitrogen loss and telemetrics to optimize fleet operation management on the farm through the use of technology that provides “real-time data around soil and crop nutrient and water requirements.”

They suggest “silvopasture” — a type of agroforestry in which trees are added to grazed lands — to store more carbon in grazing areas in the Southeast region. The team also believes repairing degraded wetland areas in the Northern Great Plains will lead to the same result.

Feed additive 3NOP is another way the team recommends for inhibiting enteric methane production at the feedlot and dairy management. However, products containing 3NOP “are not currently USDA approved but are anticipated for approval in alignment with current EU policies.”

The study also points to solid separation and anaerobic digestion for manure management in dairy operations to contain methane and nitrous oxide production.

Finally, reduced upstream emissions by using an alternative source or reduced use of electricity and energy are suggested for energy management during beef processing.

By Insha Naureen