Australia's CSIRO has identified a strain of seaweed that can reduce bovine methane emissions by more than 99 percent if added to cow feed in small amounts. This could be huge for climate change, but it also has significant benefits for farmers.

I thought this was a cow fart story; it's not. Sadly, according to Australia's CSIRO, the vast majority of bovine methane – some 90 percent of all emissions – comes from burps, not from backdraft.

But whichever end it comes from, methane represents a problem. In climate change terms, methane is a greenhouse gas 28 times more powerful than carbon dioxide. In agricultural terms, when cows burp out methane, as much as 15 percent of the energy in their feedstock is being thrown away instead of converted into meat.

For more than a decade, researchers have been aware that adding seaweed to a cow's diet made a significant reduction to that methane release, leading to cleaner agriculture and better meat production. Early tests found seaweed could cut back methane release by as much as 20 percent.

But recently, Australian scientists have been re-running tests with a variety of different species of seaweed to find out which is the most effective, and now, a very clear winner has emerged.

Asparagopsis reduces methane in the lab by up to 99%. Michael Battaglia/CSIRO

Asparagopsis taxiformis, which grows in the tropical coastal waters of Queensland, Australia, was found to reduce methane production by more than 99 percent in lab testing, smashing the previous records so badly that the researchers had to double check to make sure their equipment wasn't broken.

This unique seaweed species appears to almost totally disrupt the action of gut enzymes that produce methane, keeping feed energy in the cow and not out in the atmosphere. And it appears to be effective at low doses, compared with other strains.

The question from here is: what can be done with this? There is currently no commercial scale production facility dedicated to this species of seaweed, and the CSIRO estimates you'd need somewhere around 60,000 hectares (some 232 square miles) of seaweed farms to produce enough to give an effective daily dose to all of the 2.5 million-odd cows in Australia alone. Obviously, rolling such a thing out globally would be a massive operation.

But the benefits are clear: farmers would get significantly better value from their feedstock, which is the biggest ongoing expense of most cattle farming operations. And with livestock contributing up to 5 percent of human-generated greenhouse gases each year, there's an opportunity for some pretty significant reductions to be made.

More information: CSIRO