Can using seaweed to feed cows help slow climate change? Scripps Oceanography scientist thinks so

Researchers are trying to find ways to reduce the methane produced by cows.
(Associated Press)

Cows have become the latest culprits of global warming, scientists say. Seaweed, of all things, could help change that.

Cows emit a lot of methane, which is considered a big factor in climate change. Methane has a shorter shelf life than carbon dioxide but is much more potent in warming the atmosphere.

That’s why there is worldwide focus on reducing methane releases. Estimates vary, but more than half of all methane emissions in California come from cattle operations, primarily dairy cows, according to Inside Climate News.

Some advocates have been calling for the world’s populations to be weaned off beef and dairy products, which would reduce the population of cows.

But Americans show no sign of giving up meat, though consumption has been declining. Meanwhile, demand for meat is rising in developing countries.

Scientists at UC San Diego’s Scripps Institution of Oceanography in La Jolla and at UC Davis and the University of New Hampshire are researching ways to make cows — and livestock in general — more environmentally sound. One way to do that is to make their high-fiber diets easier to digest.

A particular type of seaweed has delivered big results, according to Jennifer Smith, a professor of marine biology at Scripps.

Smith joined a UC Davis project to cultivate Asparagopsis taxiformis, a red seaweed used in the research. Smith said adding that to cow feed has reduced methane emissions 50 percent to 98 percent. The range results from variables such as how a given cow eats and the quality of the seaweed.

“We really do believe this is going to be one of the fastest ways of reaching methane reduction targets set by the Biden administration,” Smith said.

Scientists are experimenting with different kinds of seaweed — and getting different results — while looking into other feed additives that might reduce methane from cattle.

The seaweed study in New Hampshire saw 20 percent reductions in methane from cows, Andre Brito, associate professor of dairy cattle nutrition and management at the University of New Hampshire, told CNBC.

Research on adjusting cow diets has ramped up in recent years and is now past the experimental stage. An early concern was whether seaweed in feed would make milk taste bad or reduce production. Researchers at both Davis and New Hampshire say it hasn’t.

Producing enough seaweed to make it a regular ingredient in cattle feed in the United States, let alone the world, would take some doing. Smith said a start-up company is already moving ahead to use feed with seaweed at a farm, though government approvals are still needed for commercial production.

“This red seaweed is by far the most effective of any [additive] that’s been tried,” Smith said. “Nothing comes close.”

Eventually, a massive harvesting operation would be required, possibly along with a transportation network that could have a substantial carbon footprint.

But microalgae, which is what the seaweed is, can be grown almost anywhere, raising the possibility of production facilities closer to those farms.

Algae made headlines in San Diego years ago when Synthetic Genomics of La Jolla entered a long-term collaboration with ExxonMobil to develop biofuel. The potential of algae biofuel has been studied for decades, but its advancement has been slow. Other companies, including Shell and Chevron, have either abandoned their algae biofuel quests or scaled back research.

Meanwhile, other potential additives for livestock feed are being studied. Frank Mitloehner, another UC Davis researcher, wrote that his lab had been working with essential oils and saw a 10 percent reduction in methane from cows — considerably less, he acknowledged, than in the seaweed experiments.

Burger King partnered with scientists in the United States and Mexico to develop a diet for cows using lemongrass, which the company last year said reduced cows’ methane emissions up to 33 percent on average. The fast-food chain used that in a marketing campaign. But some scientists said the research had limitations and that the methane reduction was more like 3 percent, according to The Breakthrough Institute, an Oakland environmental research center. ◆