The Paris Agreement is an international treaty on climate change, adopted in 2015. Its goal is to limit global warming to 2.7ºF. “To achieve this long-term temperature goal, countries aim to reach global peaking of greenhouse gas emissions as soon as possible to achieve a climate-neutral world by midcentury,” according to the United Nations.
Where are the beef and dairy industries with this goal? Accomplishing net zero warming, also known as climate neutrality, will require change to many industries – including beef and dairy. Methane is most commonly cited as the Achilles heel of the cattle industry.
Methane’s source
Methane is one of four greenhouse gases that’s produced by emitting “during the production and transport of oil and natural gas as well as coal. Methane emissions also result from livestock and agricultural practices and from the anaerobic decay of organic waste in municipal solid waste landfills,” according to the EPA. The agency reported methane has an average perturbation lifetime in the atmosphere of 12.4 years. In a 100-year global warming potential, methane contributes to 28 to 36 years.
“All ruminants [wild and domestic] produce methane as a byproduct of fiber [cellulose, hemicellulose and lignin] digestion by rumen microbes,” says John Hall, professor and extension beef specialist for the University of Idaho (UI) at Nancy M. Cummings Research, Extension and Education Center (REEC). “Ruminants have been doing this for the last 4.5 million years. The symbiotic relationship between the ruminant animal and the rumen microflora is what allows them to digest plant materials that cannot be used by monogastrics such as humans, pigs and chickens.”
Solutions
“Improvements in grazing management can increase carbon sequestration and reduce methane output,” Hall says. “The use of ionophores in cattle diets reduces methane. Feedlot finishing actually decreases methane production compared to forage finishing.”
“Probably the biggest impact on reduction of methane per unit of beef production is the increase in beef produced per cow [i.e., we are producing more beef with fewer cows] and the harvest of finished animals at a younger age,” Hall says.
There are improved tools and methods farmers are adopting to make raising cattle environmentally friendly. Dr. Juan Tricarico, vice president of environmental research of Dairy Management Inc., says, “Over many decades, dairy farmers have made significant improvements in their operations and sustainable farming practices – between 1944 and 2007, this led to 65 percent less water and 90 percent less land being used to produce 60 percent more milk. Between 2007 and 2017, the carbon footprint shrank by 19 percent, requiring 30 percent less water and 21 percent less land. These results have largely been the result of improved productive efficiency on farms due to management practices and techniques that reduce resource use and mitigate environmental impact. One of the greatest ways producers can impact the intensity of the milk their cows produce is by keeping their cows healthy and caring for them in a way that allows them to make milk as efficiently as possible.”
Because of the Paris Agreement, milk and beef producers now and in the future must account for methane reduction. So how is that to be accomplished? Tricarico says there are several ways to achieve this.
Through manure management
Through manure/nutrient management, “farmers across the U.S. have created manure storage systems that collect manure so the nutrients can be applied to land at the time of year when the soil and climatic conditions are suitable and best for growing crops,” Tricarico says. “These systems also prevent nutrient-rich runoff from entering waterways. Farmers have also implemented various manure technologies including reusing manure solids as bedding [instead of purchasing new bedding], anaerobic digesters to capture methane and create electricity or renewable natural gas, and covering lagoons, all of which decrease greenhouse gas emissions.”
“Manure methane emissions can be reduced or captured by processing manure before placing it in long-term storage. For example, separating the liquid and the solid in manure can reduce emissions, as can anaerobic digestion and covering lagoons. On dairies that compost, having a naturally aerated pile of compost, rather than an intensively managed pile, will reduce the methane production as well. Other simpler options, such as emptying manure storage lagoons more frequently, can reduce manure methane emissions – and emptying lagoons before warmer weather is especially critical because more methane is produced in warmer months compared to cooler months,” Tricarico says.
Through water reuse
With water use/reuse, “farmers are also adopting technologies to improve water use efficiency while also recycling and reusing water,” Tricarico says. “For instance, water used to cool milk can then be used as drinking water for cows. Other farmers use water to rinse cow manure from their barns, then recycle the resulting natural fertilizer to use on crops that are grown as feed for the cows.”
In the field
In field practices, “many farms across the U.S. have instituted practices such as cover cropping and reducing soil tillage. Cover cropping and reducing tillage can improve carbon sequestration in the soil. These practices can also improve nutrient management because growing plants and reduced soil erosion [through reduced tillage] allow the soil to uptake more nutrients rather than allowing it to wash away in runoff if it rains,” Tricarico says.
In the feedbunk
“By working with animal nutritionists, dairy farmers can optimize cow diets to reduce enteric emissions by feeding cows a balanced mix of forages, concentrates and byproducts. For example, feeding high-quality forage compared to low-quality forage reduces enteric methane emissions because high-quality forage has less lignin than lower-quality forage. Substituting byproducts for other ingredients can also reduce enteric methane emissions. Improving animal health has also been shown to reduce enteric methane emissions, as healthy cows produce milk more efficiently than their counterparts. Feed additives, which can prevent methane or change how a cow’s stomach processes feed, can offer farmers an additional solution for enteric methane reduction. Although one feed additive is approved for use today, most are currently in the research and development stage,” Tricarico says.
Differences
There are “vast differences between beef and dairy,” says Kim Brackett, who sits on the Idaho Cattle Association board of directors and is a cow-calf producer. Methane emissions is only one part of the equation, and carbon sequestration is another part – though they are intertwined.
“Carbon (C) neutrality is based upon the premise that we acknowledge our C emissions, but when sequestration is accounted for, the cattle industry is C neutral. It’s a different form of C accounting. So the dairy side doesn’t have a lot of sequestration to put into that side of the equation. They have to track their metrics back to the farms where they purchase feed, and that farm will need to have cover crops or some other method to sequester C. On the cattle side, it’s the cow-calf segment that does the sequestering. Without us, the feeders and packers would have a difficult time reaching neutrality. Feeders are similar to dairies because they are also confined operations and some may have their own farms to grow corn; most of them will have to track emissions and sequestration to the farms where they purchase feed.”
