For years we’ve all seen the figure from the 2006 report from the UN’s Food and Agricultural Organization, “Livestock’s Long Shadow,” saying livestock production accounts for 18% of global greenhouse gas (GHG) emissions .
That finding was debunked years ago, but journalists and activists continue to use it to promote a vegetarian lifestyle.
The number is inaccurate overall, but especially for U.S. beef production. The largest contributor to GHG emissions in beef production comes from converting tropical forests to grazing land, where burning directly releasing carbon and deforestation reduces carbon sequestration in the future.
A new study, recently published in the journal Agricultural Systems, is the most comprehensive beef cattle life-cycle assessment (LCA) ever completed, and tells a much different story. The report, , titled “Environmental Footprints of Beef Cattle Production in the United States,” authored by researchers from USDA, NCBA and the University of Arkansas, indicates that beef production, including the production of animal feed, is responsible for only 3.3% of greenhouse gas emissions in the U.S. And, by improving production efficiencies, U.S. beef producers have avoided 2.3 gigatons of carbon emissions since 1975.
Other notable findings include:
- Cattle consume just 2.6 pounds of grain per pound of beef carcass weight. This is comparable to feed conversion efficiencies of pork and poultry. Also, nearly 90% of the feed used in a grain-finished system is inedible to humans, meaning these plants can only provide value to humans when they’re upcycled by cattle into high-quality protein.
- The corn used to feed beef cattle represents approximately 9 percent of harvested corn grain in the U.S., or 8 million acres, in contrast with ethanol production, which accounts for 37.5% of corn acreage in the U.S.
- On average, it takes 308 gallons of water to produce a pound of boneless beef, dramatically less than previous estimates as high as 24,000 gallons. The researchers also note that water use by beef is only around 5% of U.S. water withdrawals, and this water is recycled.
- Total fossil energy input to U.S. beef cattle production is equivalent to 0.7% of total national consumption of fossil fuels.
The authors say these data provide a baseline for future assessments and evaluation of the potential benefits of mitigation strategies. They also recommend additional work to complete this full-chain LCA, better quantify the human edible feeds consumed in beef production, and to more fully assess opportunities for improving sustainability.
The bottom line: You can continue feeling good about your role in the cattle industry. No system is perfect, and we’re still learning how to reliably measure sustainability. But as veterinarians help producers adopt more efficient practices, we’ll see continuous improvement.
The Beef Checkoff offers an infographic illustrating key findings from the report.
For more on beef sustainability, see these articles on BovineVetOnline.