Seaweed feed reduces methane emissions in cows

Methane is one of the most potent greenhouse gasses - about 34 times stronger than carbon dioxide.[i] Most of the world’s methane emissions can be traced back to three causes: biomass burning, the oil & gas industry and the ruminant livestock industry.[ii]

Ruminant livestock are mammals with unique digestive systems, allowing them to extract plant nutrients through a process called enteric fermentation. These mammals include cattle, sheep and goats. Amongst them, the greatest methane emitter is the cow. There are an estimated 1.4 billion cows around the world, most of which are farmed for meat and dairy products.[iii] Each one of these cows produces between 100 and 300 liters of methane per day - making the cattle-farming sector one of the largest methane emitters globally. In fact, the industry accounts for an estimated 15 percent of the world’s anthropogenic greenhouse gas emissions.[iv]

We need to cut the industry’s methane production. One solution is to reduce our meat and dairy consumption - with less demand; fewer cows are required to fulfill it. Even so, whilst individuals are gradually altering their lifestyle choices, meat and dairy consumption remains critically high. Given the severity and time sensitivity of the climate emergency, a single solution is not enough – it must be tackled from all angles. Whilst reducing demand for cattle is one strategy; reducing the cow’s methane production is another. But how?

It’s actually quite simple. If methane is a byproduct of the cow’s digestive system, then we must target the object of digestion - food. Scientists tackling this very question have come up with a solution, significantly reducing methane emissions without radically altering the cow’s existing diet. In fact, studies show that supplementing just 0,5% of a cow’s diet with red seaweed can reduce his enteric methane emissions by up to 80%.[v] And a sprinkling of seaweed is all it takes.

What’s more, the very act of growing seaweed is in itself a powerful climate solution. Seaweed acts like a bio-filter, improving surrounding water quality and working to restore the ocean’s natural pH balance as it grows. When done right, seaweed farming doesn’t deplete the environment, it restores it. Because it requires no fresh water input and doesn’t compete for arable landmass - seaweed farming is are markably sustainable industry.  

If we are going to tackle the climate emergency, we need to decrease our methane emissions and we need to do it fast. The cattle farming industry is in need of a green reform. Intelligent and sustainable solutions do exist; we just need to get serious about implementing them. Seaweed offers a clear opportunity for methane mitigation; we must seize it now. Let's grow more seaweed to fight for a greener world.





[iv] Available online:

[v] Roque BM, Venegas M,Kinley RD, de Nys R, Duarte TL, Yang X, et al. (2021) Red seaweed (Asparagopsistaxiformis) supplementation reduces enteric methane by over 80 percentin beef steers. Availableonline: