11 March 2019
In recent years, livestock production has been called out heavily for its contribution to greenhouse gas emissions and global warming. A new life-cycle analysis of the US beef industry, completed by the USDA's Agricultural Research Service, has quantified the industry's resource usage and emissions. It found that in 2016, beef cattle production contributed 3.3% of US GHG emissions, while the wider agricultural sector contributed a total of 9%. By comparison, the electricity and transportation sectors made up 56%.
An Agricultural Research Service (ARS) led team has completed a comprehensive life-cycle analysis quantifying the resource use and various environmental emissions of beef cattle production in the United States. The aim is to establish baseline measures that the U.S. beef industry can use to explore ways of reducing its environmental footprint and improve sustainability.
"The environmental footprint of producing beef has long been debated. One challenge is that the impacts extend beyond just those associated with growing the animals and include the impact of producing feed and other inputs. This is further complicated by the diversity of ways that beef cattle are managed and fed," commented Marlen Eve, ARS deputy administrator for natural resources and sustainable agricultural systems. "It is important to have an accurate quantification of these impacts to provide a baseline against which production system sustainability can be assessed and improved."
Led by ARS agricultural engineer Alan Rotz, the team's analysis encompassed an array of different types of cattle operations, reflecting a beef supply chain that's among the most complex food production systems in the world. Indeed, the scope of the analysis spanned five years, seven cattle-producing regions and used data from 2,270 survey responses and site visits nationwide. This ensured the results weren't limited to a single region, where climate, soil, production practices and other factors can differ from other parts of the country, added Rotz, with ARS' Pasture Systems and Watershed Management Research Unit in University Park, Pennsylvania.
Among the results to emerge thus far:
The seven regions' combined beef cattle production accounted for 3.3 percent of all U.S. GHG emissions (By comparison, transportation and electricity generation together made up 56 percent of the total in 2016 and agriculture in general 9 percent).
Fossil energy (for example, fuel) use in cattle production accounted for less than 1 percent of the total consumed nationally.
Cattle only consumed 2.6 pounds of grain per pound of beef cut weight (or, butchered carcass weight), which was comparable to pork and poultry.
Beef operations in the Northwest and Southern Plains had the highest total water use (60 percent combined) of the seven regions analyzed. Irrigating crops to produce feed for cattle accounted for 96 percent of total water use across all the regions.
"We found that the greenhouse gas emissions in our analysis were not all that different from what other credible studies had shown and were not a significant contributor to long-term global warming," Rotz said.