Methane traps 84 times more heat than carbon dioxide, in a period of two decades. "Methane pollution causes a quarter of global warming"
Cows are among the most numerous mammals on Earth (thanks to us) and, as a result, these placid bovines play an important role in contributing to climate change (again thanks to us). Forests have been cut down to make way for grasslands and cattle ranching, leaving a large carbon footprint.
Then there's this: Animals contribute directly to climate change by releasing large amounts of methane, a potent greenhouse gas, through their burps and, well, farts. Methane traps 84 times more heat than carbon dioxide in a period of two decades. "Methane pollution causes a quarter of the global warming that we are experiencing right now," said Fred Krupp of the Environmental Defense Fund.
But what if we could get cows to produce less methane by modifying their diet? A team of researchers from the University of the Sunshine Coast in Australia say they have an answer for that kind of dietary adjustment in the form of pink algae. If all the cows in Australia were fed this nutritious bloated seaweed, Australia's methane emissions would be 10% less, they say.
The algae, called Asparagopsis taxiformis, are abundant on the Queensland coast and are generally liked by cows. “Seaweed is something that cows are known to eat. In fact, they hang out on the beach and nibble a bit, ”says associate professor Nick Paul, who leads the research team.
"When less than 2 percent of the dry matter is added to the cow's feed, these seaweeds completely eliminate methane production," adds Paul. "It contains chemicals that reduce microbes in cows' stomachs that cause them to burp when they eat grass."
Paul and his team analyzed 20 different species of tropical macroalgae to see which one might work best to reduce the amount of methane produced by cows. Asparagopsis taxiformis proved to be the only one by inhibiting 98.9% of the methane production of the ungulates after 72 hours.
Scientists are now working on a way to grow lots of seaweed in large open-air aquaculture tanks to mix with the diets of more and more cattle in Australia and elsewhere.
"We know the chemical composition of asparagopsis and we know the chemical compounds that actually reduce the production of methane in cows, so now we want to maximize the concentration of that chemical so that we can use less algae for the same effect," says Ana Wegner, a Scientist working on the project.