Written by Sarah Beck, 2023-2024 Food-Inspired Resilience and Equity Intern for the N.C. Cooperative Extension – Lee County Center

One of the major contributors to climate change is methane emissions from cattle farming. According to the United States Environmental Protection Agency, a single cow produces between 154 to 264 pounds of methane gas each year. If you take a look on a global scale, there are over 1.5 billion cattle raised specifically for meat production worldwide, emitting at least 231 billion pounds of methane annually. Greenhouse gases, such as methane, trap heat in the atmosphere, leading to a rise in global temperatures. Methane emissions are particularly harmful because it is one of the most potent greenhouse gases in the atmosphere. In fact, the EPA found that methane is 28 times more powerful than CO2 on a 100-year timescale and 80 times more powerful on a 20-year timescale. All things considered, cattle farming stands as the number one agricultural source of greenhouse gas emissions globally.

Because of the substantial impact of methane on the atmosphere and climate, scientists are actively pursuing solutions. While their recommendations may vary, a common thread is clear: a rapid reduction in greenhouse gas emissions is necessary. A joint study conducted by Stanford University and UC Berkeley advocated for a phase-out of animal agriculture, switching to a primarily plant-based diet across the world. These scientists found that if animal agriculture can be phased out over the next 15 years, “it would have the same effect as a 68% reduction of carbon dioxide emissions through the year 2100. This would provide 52% of the net emission reductions necessary to limit global warming to 2 degrees Celsius above pre-industrial levels, which scientists agree is the minimum threshold required to avert disastrous climate change.” The research indicated that phasing out animal agriculture entirely would yield the most significant reduction in greenhouse gas emissions. However, nearly 90% of emissions reductions could be met by specifically phasing out cattle and other ruminant farming operations.

While this phase-out would cause drastic, positive change in climate outcomes, it would likely be challenging to implement such a radical change across the globe— especially on the fast timeline necessary to mitigate the effects of climate change. Moreover, the cultural significance of consuming meat and dairy is unlikely to falter. Not all of us are willing or able to eliminate meat from our diets. Not all farmers who raise livestock are going to be able to transition away from meat and dairy production on their farms. Given these challenges, what else can we do?

Fortunately, there are a handful of alternative solutions that could have a significant impact on reducing methane emissions besides cutting meat out of our diets, one of which is currently growing along our coastlines. There is a great deal of ongoing research that is focusing on integrating red seaweed into cattle feed because it has been found to reduce the amount of methane cows produce. There are a couple of red seaweed varieties being studied, one being Asparagopsis armata. A recent research trial discovered that when dairy cows were fed a diet composed of 1% Asparagopsis armata, their methane emissions were reduced by over 60%. It is also noteworthy that this trial uncovered that introducing seaweed into the dairy cows’ diet did not change the taste or quality of the milk produced, which is important for producers and consumers. Asparagopsis taxiformis, another species of red seaweed, has been found to be even more effective, lowering methane emissions by 98% when it constitutes 0.2% of cattle feed, a mere fraction of the total diet! These findings suggest that incorporating red seaweed into cattle diets could be a game changer for helping reduce global methane emissions. Beyond positive climate impacts, there are also several other benefits that farmers may gain from feeding their cows seaweed. Cattle were found to gain weight with less feed when seaweed was included, and in some cases, dairy cows were found to produce more milk on a seaweed diet.

However, there is a significant challenge with using red seaweed in cow diets: the current amount available through wild harvests would not be able to supply the necessary quantities to integrate seaweed on a broad scale in cattle diets. The Missouri Science & Technology (MOST) Policy Initiative found that introducing feed containing 1% red seaweed into the diets of all cattle in the United States would require more than half of the current seaweed production. Therefore, farmers and scientists are now working to figure out how to cultivate red seaweed out of the wild, as well as exploring whether other regional seaweed varieties could provide the same benefit in helping reduce methane produced by cows’ digestive processes.

For more information on the potential impacts of red seaweed to assist with climate change and cattle farming, contact N.C. Cooperative Extension in Lee County at (919) 775-5624.

Sources

• Agriculture and Aquaculture: Food for Thought 
• Cows and Climate Change – Making cattle more sustainable
• Replacing animal agriculture and shifting to a plant-based diet could drastically curb greenhouse gas emissions, according to new model
• Inclusion of Asparagopsis armata in lactating dairy cows’ diet reduces enteric methane emission by over 50 percent
• A meta-analysis of effects of dietary seaweed on beef and dairy cattle performance and methane yield
• Seaweed for Cattle Feed
• Effects of Red Seaweed on Milk Production and Methane Emissions
•  What Is the Greenhouse Effect? 

Sarah Beck is the 2023-2024 Food-Inspired Resilience and Equity Intern for the N.C. Cooperative Extension – Lee County Center