Why feeding seaweed to cows is not a solution, but a distraction
For years, animal agriculture has been a significant driver of environmental destruction, largely due to methane emissions. As global warming accelerates and environmental crises intensify, the animal industry and its supporters are scrambling for solutions. You may have seen headlines touting a supposed breakthrough: the claim that seaweed could be the key to addressing the environmental damage caused by animal agriculture. Research suggests that adding small amounts of certain seaweed to cattle feed can reduce methane emissions. While the idea sounds promising, feeding seaweed to cows isn’t the solution. Let’s explore why.
First, what is methane and why do its emissions matter?
Methane is a powerful greenhouse gas with a warming effect that is 86 times stronger than carbon dioxide. It is exceptionally good at trapping heat in the atmosphere and is responsible for around 30 percent of the rise in global temperatures. However, unlike other greenhouse gases, methane has a much shorter lifespan—around 12 years. This means that reducing methane emissions can deliver rapid benefits within just a few decades.
Animal agriculture accounts for 32 percent of the human-caused methane emissions. Cows, in particular, are notorious for their methane emissions, which are released primarily through burping. Due to the growing global demand for animal products, methane emissions from animal agriculture are expected to increase 60 percent by 2030.
Animal agriculture: accountability or denial?
Algae based SeaGraze. Photo: Symbrosia
Despite the animal industry’s best efforts to sow doubt, the evidence is clear: for decades, scientists have been urging us to reduce our consumption of meat and dairy. Yet, rather than making meaningful changes to their production or practices, the trillion-dollar industry has focused on strategies that market their products as more ‘climate-friendly.’ Their mantra? ‘’It’s not the cow; it’s the how.’’
Some of their tactics include carbon offset programs, promoting labels like ‘local’ or ‘grass-fed’, and improving manure management. Another practice gaining considerable attention is the use of feed additives. Over the years, the industry has championed so-called potential breakthroughs including oils like sunflower and canola, garlic, green tea, and commercial additives such as Agolin.
Now, the industry has added a new feed additive to the list: seaweed. Specifically Asparagopsis taxiformis, a type of red kelp. This seaweed contains high levels of bromoform, a compound that prevents methane from forming in a cow’s stomach. In controlled studies, methane reductions of up to 80 percent, and in some cases even 99 percent, have been reported. However, one of the world’s longest commercial trials of Asparagopsis, conducted by Meat and Livestock Australia (MLA)—the red meat industry’s marketing and research group—revealed much lower reductions. The trial found that the seaweed supplement reduced methane emissions by only 28 percent, much lower than the expectations set by earlier experiments. Additionally, the cows on the supplement produced less milk, consumed less feed, and weighed 15 kilograms less by the time they were supposed to be sent to slaughter. Since the cows needed an extra 35 days to regain their weight, the actual methane reduction is closer to 19 percent, not 28per cent.
But, there’s another catch. “Bromoform in its pure form is toxic and harmful to health,” warns Wouter Muizelaar, a researcher at Wageningen Livestock Research. His studies revealed abnormalities and signs of inflammation in animals exposed to bromoform.
So, what’s the outcome?
Cows and their bodies don’t really like Asparagopsis. The methane reduction was not even close to what was promised. It will take much more money and research to make meaningful progress and we continue to delay the essential changes we need. The industry is holding on to potential technical fixes, but even if seaweed could eliminate 100 percent of methane emissions right now, it still wouldn’t address the other significant harms caused by animal agriculture. Animal agriculture is responsible for displacing indigenous tribes, occupying 80 per cent of all agricultural land worldwide, driving biodiversity loss, contributing to deforestation, and depleting natural resources. If there are no changes to policy or behavior, meat consumption is expected to increase by 60-70 percent by 2050. And let us not forget the individuals who are killed by this industry. Every single day, 900,000 cows, 1.4 million goats, 1.7 million sheep, 3.8 million pigs, 12 million ducks, 202 million chickens, and hundreds of millions of fish are slaughtered. These are sentient beings, killed in a system built on suffering and exploitation.
The need for a systemic shift
According to Stanford, the worldwide phase-out of animal agriculture, combined with a global shit to a plant-based diet, would effectively halt the increase of atmospheric greenhouse gases for 30 years. Alexia Akbay, CEO and founder of Symbrosia, a startup producing the seaweed-based feed additives, acknowledges; "Most of our team is vegetarian or vegan, so we see our solution as complementary to a shift toward a more plant-based diet." So, even those at the forefront of feed innovation acknowledge the necessity of a systematic shift to a plant-based food system.
Ultimately, the science is undeniable- choosing plants over animal products is the most effective way to combat the urgent crises of our time. It’s not a question of if change will come, but when it will come. By acting now, we can mitigate the worst effects of climate change, save trillions of animals, and stop the exploitation perpetuated by the animal industry. The sooner we act, the better. Seaweed is not the solution—it’s a distraction.
Species Unite offers a free 30-Day Plant-Powered Challenge for anyone interested in starting their plant-based journey. With 70 percent of our 150,000-strong Species Unite community already incorporating more plant-based meals into their diets, it's clear that many are recognizing the connection between diet, climate catastrophe, and animal cruelty. Sign up for the Challenge here.
Written by Sarah-Manon Blok
Sarah-Manon Blok is a freelance journalist dedicated to using food as a catalyst for meaningful change. With a focus on sustainability and ethics, she inspires others through her plant-based catering service Planty To Love, her regenerative farm, and her writing to make more conscious and impactful choices.
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