The problem is largely due to methane, a powerful greenhouse gas produced by microbes that live in ruminants’ guts. Methane is over 80 times* more potent than carbon dioxide in trapping heat and is responsible for nearly a quarter of man-made global warming. The problem is only set to worsen as livestock production increases by an expected 50 percent by 2050.
In 2014, researchers at CSIRO and James Cook University demonstrated that feeding ruminants a diet consisting of just 1-2% percent red seaweed reduced the animals’ methane emissions by over 90 percent. Of 20 types of seaweed tested, one species, Asparagopsis taxiformis, showed the most promise, with nearly 99 percent effectiveness.
Additionally trials at CSIRO, the University of California, Davis and Penn State University have been completed or are underway.
These studies are confirming the initial results and demonstrating a sustained reduction in enteric methane emissions with no negative effects on animal health, milk or flesh quality.
Translating this discovery into a global solution presents many challenges. The life cycle of Asparagopsis taxiformis has yet to be controlled and it has never been farmed at scale. The world is home to an estimated 1.5 billion cattle and 1.2 billion sheep, suggesting that at least 200 million tons of Asparagopsis taxiformis will be needed to have a global impact. In 2015, only 30 million tonnes of seaweed were farmed globally.