Every day I receive questions regarding the use of seaweed for reducing methane emissions from cattle to save the planet, and every day I have to watch the disappointed faces as I give my honest opinion on the media driven interest in this technology.
Of course it is a great story! It seems like such a simple solution and we would all love the solutions to be that simple. It is a story that we want to believe, which means that not many of us are challenging it. However, for me it is a case of deja vu.
I witnessed a similar story a decade ago with the algal biofuels technology. In an analogy to the current story; it is technically correct and fascinating science in a laboratory setting, and seaweed for animal health is a well proven field of nutrition, also offering solutions to reduce the use of antibiotics. The animal health science has been going on for decades and is exciting.
However this current technology makes statements about addressing climate change by reducing methane in cattle burps which is practically unrealistic and effectively negligible for the planet. During the algal biofuels hype, I felt so powerless watching the science being misinterpreted to drive mass investment in algal biofuels technology. I saw cowboys taking advantage of the desire for ordinary citizens wanting to support a greener future. Indeed, I hosted a Great Biofuels Debate in Sydney in 2014, with Adam Spencer leading the charge with challenging questions: to paint a real picture for those who are not in the scientific debate. If you feel like watching an hour long debate on this since forgotten topic, then you can still see it here. In a nutshell however, 75% of those attending supported the algal biofuels solution walking in, and just 35% supported it walking out. For me that was an objective and factual way to present the case. For people to hear the facts and perspectives with 6 international experts, both for and against. The audience could, and did, make up their own minds. This is the type of forum that is rarely available to the community.
These technologies from the science lab are fascinating science, and present ideas and can inform us, as well as add to our resource of knowledge that could be relevant in some way, one day. But they are not a panacea for the climate threat that faces us as we speak, when we look at the big picture outside of the laboratory. The calculations being made are not being made by climate modellers; analogous to a snake oil salesman selling drugs that cure cancer. What he is really selling is hopium and people will buy that in droves.
"In an agricultural context there are risks we might trade shorter- for longer-lived gases by supporting certain products or types of production over others, but an even greater danger is that action taken on agricultural emissions might reduce the focus on decarbonization. If strong efforts are made to reduce agricultural emissions but prove expensive—in terms of monetary costs, political capital, public goodwill, or individual effort—and detract from efforts to eliminate fossil CO2 emissions then we will be climatically worse-off."
"In many cases emissions metrics are used in ways which are at best ambiguous and at worst positively erroneous. More attention should be paid to the uses and limitations of different metrics for different purposes. We call for more environmentally robust approaches in the future, including the use of multiple and alternative emission metric approaches, and modeling of the relevant impacts."
Although methane from burping cattle is a more potent greenhouse gas than CO2, it eventually reverts to the natural atmospheric CO2 that it came from, in less than 10 years. Because cattle burp methane is only 3% of greenhouse gas effects in a year, it means that if we used seaweed extracts like this to convert all cattle burp methane in the world, we would only gain 3% of a 10 year effect; which is only a few months. It is unlikely that this technology will reach all cattle in the world, or even significantly for decades. By 2050 there will hardly be any effect at all. Maybe a few weeks of thinking time at best, by which time we need to have resolved real fossil-carbon emissions well and truly.
"The key question for livestock is do ruminant herds add to additional methane, meaning additional carbon in the atmosphere which leads to additional warming?
The answer is clearly “no”.
Oxford University authors including Professor Myles Allen have shown that biogenic methane is not the same as fossil methane.
It is the same chemically, but the origin and fate “are totally, drastically different”."
Here are some reasons why this technology is a distraction from real change:
- The seaweed technology simply speeds the conversion of methane to atmospheric CO2, from which it came. It does not address fossil sources of carbon to the atmosphere at all.
- Up to 61% of greenhouse equivalent gases in cattle production are from other emissions including fossil emissions that increase net greenhouse gases.
- A lot of methane is from cattle manure and not burps. In fact using methane from cattle manure and industry waste instead could actually reduce fossil-carbon. Manure and organic waste can be used as an energy source through biogas plants, which is a better conversion process for methane as it replaces fossil carbon use to create energy. Australia is behind globally on utilising biogas . Biogas from cattle waste products would result in a net fossil carbon reduction for cattle production, unlike the technology for reducing methane in cattle burps. This technology exists today and, used correctly, will contribute to net fossil carbon emission reductions.
- There is a 300 times more potent greenhouse gas than CO2 in cattle urine and dung and the pasture to feed cattle. Nitrous (N2O) oxide in the atmosphere does not disappear in 10 years like methane, it takes 110 years, and cattle are responsible for 25% (or 75% in WA) of agricultural nitrous oxide emissions in Australia.
- Beef production is inefficient use of the food chain, with a 96% food loss compared to eating plant protein – this means that if you eat 100g of beef, you could have fed an equivalent of 20 people instead with 100g of plant sources. Nearly all other animal sources of protein are better choices as well; especially marine species like prawns.
- The seaweed cultivation technology for this species for Asparagopsis has not been developed fully. There are other feeds, including seaweeds, that are already available at commodity scale (for example in the northern hemisphere) and that are known to contribute to lower methane production. Making these crops available for this climate purposes despite scaled production is still not currently financially viable, and it might be prudent to focus on these existing crops rather than imagining that an undeveloped technology will suddenly unlock this opportunity. The improved animal nutrition from seaweeds and productivity in the sector, as well as reducing a reliance on antibiotics, could have very meaningful benefits to animals and the environment.
- The processing of the seaweed and handling of the active product, bromoform, has many technical challenges that are unresolved, including it's carcinogenic and ozone depleting properties. NASA has measured how and when bromoform from this seaweed lasts all the way up to the stratosphere where it damages our ozone protection. This is effectively undoing all of the effort we made in removing CFCs from refrigerants. An international scientific publication is calling for a formal assessment on which species of seaweed and what cultivation methods will contribute to devastating destruction of our ozone layer.
- The longevity of the effect on the gut shift is unknown, and the applicability to all livestock with diverse genetics, diverse microbiomes and diverse feeds is unknown. Manipulating the gut to change one specific gas producing process is not as simple as it sounds.
- The biggest gains for reducing greenhouse gas emissions from agriculture is to reduce the consumption of red meat, and increase the consumption of plant based proteins. This does not mean we need to eliminate meat totally from our diet, but it is estimated that we should all reduce red meat to once per week. Other meat can be reduced to half a serve per day to reach the 2050 target emissions for food by 52%, and to be within the limits of food production capacity of planet earth. This is good news and not hard to achieve – a healthy diet does not need to include more meat than this and our health outcomes will be better off with an increase in plant protein sources.
- Seaweed farming for human food and animal food can produce up to 40 tonnes of protein per hectare and annum, compared to 3 tonnes for red meat, including all essential amino acids, vitamins B12 and bioavailable iron. It also uses seawater instead of fresh water. Therefore replacing both humans and animal diets with say 5-10% with nutrition from seaweeds, instead of land crops and animal protein, will make a bigger dent in fossil carbon emissions as seaweed for nutrition is more efficient food.
- Plant protein in the human diet does not create methane like it does for cattle, so it is better to grow crops for people and not for as many cattle. The research for the methane reduction story was funded by Meat and Livestock Australia (MLA), not a sustainability fund. That is like the coal industry funding clean coal research. There are real fossil carbon reducing technologies, that might not be as interesting in the media, but that will have a real impact for meat and livestock today. There are real fossil carbon gains to be made from the beef industry, and it would be preferable in my view that MLA should focus on these, in addition for seaweeds for real animal nutrition.
- Maybe the suite of challenges faced by the beef and dairy industry, and that is forcing them to find blue sky solutions, should instead acknowledge that the bio-atmospheric processes of carbon and cattle are not part of the fossil carbon emissions equation. Recent climate modelling suggests that the focus on methane alteration in livestock is not going to have much of an impact to improve climate change outcomes. Let's look at what fossil emissions can be reduced in the industry, and then accept that level and work out how much meat per person is acceptable on a plant with 7 billion people. Considering all of the real fossil carbon replacement technologies that are becoming a reality today, and reducing meat intake per capita, as is a current strategy in China, we will be able to address climate change starting now by investing our efforts in the right space.
- A recent international panel of ecological and phycological experts considered that:
---- "Currently, no Asparagopsis sp. supply chain is available for livestock feed and the feasibility and costs for scaling production of these species are yet to be determined."
--- "The estimated 3–3.4 MMT of dried seaweed required per year would represent over half of all seaweed currently produced globally. Supplying the global herd −1.4 billion cattle—would not be feasible, however it is presumed that widespread use of methane mitigants in smallholder or subsistence production systems is unlikely to occur due to cost and other limitations."
--- They suggest that although this has legs as a marketing strategy to drive consumer of meat products "A comprehensive framework to assess the environmental, economic and social sustainability of seaweed-based animal feeds is needed and would broaden the scope of evaluation beyond the traditional lens of animal health, productivity and profitability. "
The research in this space is interesting science, and the current media interest will undoubtedly lead to more investment. Let's hope that those in receipt of those funds can pivot their technology early enough to address the real environmental and health gains from seaweed production. Let's hope that the IPCC speaks out to burst this bubble of political spin, as more and more scientists are doing.
PhycoHealth recommends that we can make enough real choices about food today for both humans and livestock, to make the right impact, and to not spend time wishing a better future on questionable burps. Too many ifs and buts to spend time on a dubious, futuristic technology, when real things can be done today.
Latest updates in this space:
July 2023: ABC News - Landline
January 2021: A reality check on seaweed as a feedstock for cows
June 2021: "Seaweed Oil Salespersons of the Internet.” These are often people who, in fact, have never studied, touched, grown or harvested seaweeds, except during the three minute video for a social media scoop." Chopin et al 2021.