STILLWATER — When it comes to protecting the environment, blaming greenhouse gas emission problems on beef cattle or people who like a good steak is a claim that has little basis in fact.


Greenhouse gas emissions from beef production account for only 1.9 percent of U.S. total.


Unwarranted claims about cow farts have made it into the media, and as jokes offered up by late-night talk show hosts. Not only are cow farts not to blame, 98 percent of methane emissions from cattle are released through their mouth in a process called eructation.


“As with the production of all foods, beef production results in greenhouse gas emissions; however, the U.S. Environmental Protection Agency estimates direct emissions from the U.S. beef industry are only 1.9 percent of the total U.S. greenhouse gas emissions,” said Sara Place, assistant professor of sustainable beef cattle systems for Oklahoma State University’s Division of Agricultural Sciences and Natural Resources.


In short, even without consideration of any unintended consequences and impacts of alternative protein sources, completely removing beef from the U.S. diet would likely not result in huge declines in greenhouse gas emissions, but could have negative implications on the sustainability of the nation’s food system.


Beef is one of the most commonly available sources of lean protein, with 1.8 ounces of beef per day available to U.S. consumers in 2013, according to the USDA Economic Research Service’s Loss-Adjusted Food Availability Data Series. The series adjusts for food spoilage, plate waste and other losses to approximate actual intake.


“Per capita loss-adjusted beef availability has actually been declining in the United States over the past 35 years, in large part because beef production has not kept pace with U.S. population growth,” Place said.


Along with being a significant source of lean protein, beef provides key nutrients such as iron, zinc and B vitamins. Completely removing beef from the food chain would result in consumers having to seek alternative protein and micronutrient sources. Current U.S. Dietary Guidelines for Americans recommends 5.5 ounces of a lean protein per day for a person consuming a 2,000-calorie diet.


What about beef production accounting for only 1.9 percent of total U.S. Greenhouse gas emissions? By comparison, transportation and electricity accounted for 25.8 percent and 30.6 percent of total U.S. greenhouse gas emissions in 2013.


“You don’t hear many people clamoring for the elimination of electricity or transportation even though they produce much of the greenhouse gas emissions in the United States,” Place said. “Instead, the focus is on reducing emissions, either by technological advances or by switching to alternative energy sources.”


That said the U.S. beef industry as a whole still has a demonstrated history of actively developing and implementing management practices that match up animal well-being and sound agribusiness economics with environmental stewardship.


Over the years, studies by J.L. Capper, C.A. Rotz and others indicate the U.S. beef industry has made notable and measurable advances to meet consumer demand for protein while reducing the amount of natural resources – animal feed, water and land – required in producing a pound of beef.


“Data indicates greenhouse gas emissions per pound of beef produced have been reduced 9 percent to 16 percent since the 1970s, thanks to improved genetics of both the livestock and the largely inedible-to-humans plants they consume, improved animal nutrition, better operational management and the use of growth-promoting technologies,” Place said.


Further improvements in the efficiency of beef production are being continuously researched and evaluated at universities and other institutions, both in the United States and abroad.


“We’re not resting on our laurels,” said Clint Rusk, head of OSU’s department of animal science. “There are opportunities to further reduce beef’s overall greenhouse gas emission impact, and they are not limited to the cattle and agribusinesses that produce the nation’s beef. One of the most notable is in the area of consumer waste.”


USDA research indicates more than 20 percent of edible beef is wasted at grocery stores, restaurants and in the home.


“As with most foods, the amount of non-renewable resources used and the environmental impacts used in producing the portions of beef ending up in a landfill often are overlooked,” Rusk said.


Consumers could improve beef sustainability by 10 percent if related food waste were reduced by half, according to the 2014 Beef Checkoff Sustainability Executive Summary.


Rusk and Place stressed it is important for people not to overlook the many positive contributions of beef production as they relate to the sustainability of the U.S. food system when talking about reducing greenhouse gas emissions.


“Cattle have the ability to utilize grass forages and byproducts such as distiller’s grains that are not fit for human consumption,” Place said. “Specifically, cattle can utilize cellulose, one of the world’s most abundant carbon-containing molecules that are inedible to humans. Consequently, U.S. beef producers feed their cattle from food sources that are not in direct competition with human nutritional resources.”


In addition, cattle can convert low-quality feeds grown on lands not suitable for cultivation that humans won’t eat into high-quality protein that can sustain humans, thereby reducing soil erosion and enhancing carbon storage, both of which provide significant environmental benefits.


Furthermore, integrated crop and beef systems – using cattle to graze crop residues and cover crops – can lead to many positive and sustainable environmental outcomes. A cover crop is planted primarily to manage soil erosion, soil fertility, soil quality, water, weeds, pests, diseases, biodiversity and wildlife in an agricultural ecosystem.


“Listen to a discussion about cover crops and beef production systems and you are likely to hear phrases like ‘soil water-holding capacity’ and ‘enhanced nutrient cycling,’” Place said. “Environmental stewardship is as key an aspect as animal well-being and operational economics when we talk about sustainability in beef cattle systems.”


OSU Division of Agricultural Sciences and Natural Resources fact sheets about the impact of beef production and consumption on greenhouse gas emissions and other beef, environmental and land-use topics are available online by accessing http://osufacts.okstate.edu.


Oklahoma ranks third nationally in the number of beef cows and fifth nationally in the total number of cattle and calves, according to the USDA National Agricultural Statistics Service data.