Seaweed – A Methane Solution

Seaweed – A Methane Solution

For two weeks at the beginning of November the world’s media covered, and weighed in on, Climate Change and the world’s nations future strategy in tackling and mitigating the issue. What might be considered one of the only concrete outcomes of the 2 week debacle is the pledge of 105 nations to cut methane emissions by at least 30% by 2030 (including the 15 largest emitters). It is thought more nations will join the pledge to dramatically cut their emissions of what is considered a short-lived but impactful greenhouse gas. 

“Cutting back on methane emissions is one of the most effective things we can do to reduce near-term global warming and keep to 1.5°C,” said Ursula von der Leyen, the European Commission president, referring to the 2015 Paris Agreement’s toughest climate goal (New Scientist, 2021).


Whilst carbon dioxide is usually public enemy no.1, when it comes to tackling greenhouse gasses methane has recently taken centre stage. For good reason, the hazardous air pollutant is linked to 1 million premature deaths around the world every year. Further, over 20 years, methane is x80 more potent at warming the atmosphere than carbon dioxide is. The call for urgency in enacting the methane pledge is understandable, considering “methane has accounted for roughly 30% of global warming since pre-industrial times and is proliferating faster than at any other time since record keeping began in the 1980’s (UN Environmental Programme, 2021).

Agriculture, and in particular livestock, is the primary contributor to methane emissions, accounting for 32% of the total. The emissions are produced in the form of manure and gastroenteric releases (burps and farts). With the global demand of animal products only increasing, the problem is only becoming more impending. Cows are the largest contributor, being responsible for 2/3rds of all livestock emissions. Making them an opportune target for leveraging impactful change.  


It has been found that adding a tiny amount of a species of red algae (Asparagopsis taxiformis) into cows feed can reduce the amount of methane produced by 85%. Only 0.2% of the cows’ meal needs to be the red algae, 200 million tonnes of the algae would be needed annually to sustain the world’s cattle. 

Frustratingly, Asparagopsis taxiformis is particularly difficult to grow, and ultimately to scale. Greener Grazing was born out of decades of research and is finally bringing their solution to market, with the first commercial tests happening this year in Vietnam. The end goal is to produce spore impregnated ropes that can be grown in different global locations, acting as a carbon sequesterer and methane mitigator. 

Greener Grazing was the first of such projects and has conceived other projects such as Sea Forest in Tasmania. Hopefully there will be many more. Whilst ideally we wouldn’t have to attenuate the methane crisis we face, it would be pragmatic to understand that the issue is only growing, and that projects such as Greener Grazing and Sea Forest are hugely impactful ways to peg back the issue. As part of the COP26 methane pledge, we will hopefully see red algae playing its potentially significant role in the emissions reduction.