(File image). Photo: RNZ / Rebekah Parsons-King
For decades, scientists have been working on a methane-reducing vaccine for cows with little success, until now.
A prototype vaccine by US-based start-up ArkeaBio, in partnership with Aotearoa's AgriZeroNZ, is showing promise following a trial with 10 cows that saw emissions drop by up to 15 percent.
ArkeaBio founder and CEO Colin South told Saturday Morning they were the first to publish successful results.
"No one's ever shown previously that you're able to use a vaccine to mitigate methane.
"At the moment, we're getting around 13-15 percent reduction over an extended period but both the efficacy and the timeline that it remains in effect for aren't yet long enough."
Anti-methane vaccine could reduce impact of cow burps
South said there were no side effects for the cows.
"Methane production is purely from an organism that's a scavenger - it picks up stray hydrogens from CO2 and turns it into methane, it's not totally required for the animal's normal function."
In fact, the metabolic energy needed to produce that methane could be redirected to help the cow get more energy out of food instead.
The burps and farts of farm cows around the globe were a major contributor to methane pollution, and South said atmospheric methane was a highly potent greenhouse gas.
"Although atmospheric methane degrades into CO2 in 12 years... it's something like 84 times the warming impact of carbon dioxide and since 1990 the levels in the atmosphere have doubled."
South said 30 percent of the current annual warming of the climate was due to methane.
"The annual emissions by cattle, sheep and deer, which we call enteric methane, make up about 6 percent of annual greenhouse gas emissions. It's about 3 billion tonnes a year of CO2, so it's a pretty substantial number about equal to that of the methane leaks from fossil fuels or four times as many emissions as the airlines' CO2 can give us."
Of the 1.2 billion cattle in the world, the major players were Brazil, Argentina and India, South said.
"Between those three countries, you've got more than 60 percent of the world's cattle."
South said a methane reducing vaccine would complement other innovations in the climate change space, such as methane-reducing grass.
He said the company was hoping to have its first commercial methane-reducing vaccine ready in two to five years' time.