Ruminant Math: How Seaweed is Helping Cut Methane at Scale | CH4 Global

By Rowena Pullan, Chief Brand Guardian and Kate Ivory, Senior Sustainability Manager

September 25, 2025

Methane isn’t just another greenhouse gas — it’s one more potent than CO2 and second most plentiful after CO2. It has more than 80 times the global warming potential of CO₂ over a 20-year period (GWP20) and 28 times over a 100-year period (GWP100). Both perspectives are valuable: GWP20 highlights the urgency of near-term action, while GWP100 helps us understand longer-term climate planning. At CH4 Global, we use both GWP20 and GWP100 because they offer different, but equally important, lenses for understanding methane’s impact.

And methane matters. According to the IEA, it accounts for about 30% of the warming we’ve experienced since the Industrial Revolution.

A major source of that methane? Ruminants, especially cattle. A single cow can burp out up to 100 kilograms (220 pounds) of methane per year, and that adds up fast. Roughly 1.5 billion cows globally emit about 150 million metric tonnes of methane every year, mostly through digestion.

If we’re serious about slowing global warming in the near term, addressing methane from livestock is a practical place to start.

A Seaweed-Based Solution That Makes a Measurable Difference

CH4 Global’s Methane Tamer™ is a feed additive made from Asparagopsis seaweed, designed to reduce enteric methane emissions in cattle.

When added to a cow’s feed, this seaweed targets the enzyme responsible for methane production in the animal’s digestive system. Reductions of 70-90% are achievable, depending on dosage and formulation.

Here’s what that means in climate terms:

• A 70% reduction equals about 1.96 tonnes of CO₂-equivalent (CO2e) per cow per year (GWP100).
• A 90% reduction equates to 2.52 tonnes CO₂-e annually.
• Using the GWP20 metric, a 70% reduction is equivalent to 5.6 tonnes CO₂e avoided per animal per year.

This approach doesn’t require farmers to install new systems or equipment. They just make a small change in feed that leads to significant reductions. That’s the basis of what we call “cow math”: practical, scalable, and scientifically grounded.

Behind CH4 Global’s “Cow Math”

We’ve built Methane Tamer around a science-based, farmer-friendly approach to methane measurement and reduction. Here’s how it works.

Accounting for Key Variables

We know that not all studies — or seaweed — are equal. That’s why we account for:

• Measurement method: Respiration chambers typically show greater reductions than portable GreenFeed machines, for example.
• Seaweed quality: Some studies show poor results because the seaweed was poor quality and delivered insufficient levels of the active compounds. CH4 Global ensures a minimum concentration of actives in every dose to ensure the optimum reduction of methane.
• Palatability: Cows need to eat it. In one study, seaweed steeped in oil led to low reductions (28%) because the cows didn’t eat enough of it. CH4 Global’s formulation is designed to be palatable and farmer-friendly, so cattle consistently consume the right dose.

Our Meta-Analysis Approach

To calculate methane reductions, CH4 Global uses a meta-analysis methodology, which is a synthesis of multiple peer-reviewed scientific studies that meet rigorous standards. This approach is:

• Approved by Verra, the standard-setting body for carbon credit programs
• More consistent and less burdensome for farmers than on-farm measurement
• Designed to reflect real-world variability, rather than cherry-picked results

While Verra limits the number of studies that can be formally referenced in a crediting methodology, we continue to review a broad range of studies to ensure our assumptions reflect the wider body of research.

This approach delivers a mathematically valid, transparent, and farm-friendly way to measure emissions reductions. And it really is as simple as applying the numbers. Farmers using Methane Tamer don’t need to install new infrastructure or perform complex calculations to prove they’re making a difference.

What farmers can count on with Methane Tamer

Methane Tamer Beef Feedlot has been developed to ensure it contributes the highest levels of product efficacy:

• Consistent levels of active compounds: Made from whole dried Asparagopsis grown to exacting standards, Methane Tamer delivers consistent levels of methane-reducing bioactives. Using the whole plant preserves over 100 valuable compounds, not just bromoform, to maximize impact. Plus, the product is stabilized to ensure effectiveness on the farm.
• Proven palatability: Made from whole dried Asparagopsis combined with other ingredients, Methane Tamer has been shown in feeding studies to be palatable and that cattle do not sort it out of their feed.
• Backed by independent science: Multiple independent studies show Asparagopsis can cut methane emissions by up to 90%. Research confirms it’s safe, with no negative effects on animal health or meat and milk quality.

Dispelling Common Misconceptions

We hear this often: “How can you prove reductions without tracking every animal?” It's a fair question. The answer lies in rigorous, science-backed modeling.

• Misconception: You need sensors on every cow.
• Reality: Our calculations are based on accepted baselines and peer-reviewed studies.
• Misconception: You can’t prove reductions without internal data.
• Reality: We use independent, peer-reviewed research and third-party audits.
• Misconception: More measurement always means better accuracy.
• Reality: Too much data collection can distract from real-world impact.

The broader impact is what matters: we’re cutting methane and doing it in a way that works in practice, not just in the lab.

A Climate-Positive Process From Day One

Even before Methane Tamer reaches a feedlot, our production process is offsetting more emissions than it creates.

Our early lifecycle analysis (LCA) — based on our Louth Bay EcoPark — shows that we’re already climate-positive. That means:

• The methane reductions we enable exceed the emissions from our operations.
• Our calculations use data from our 10 operational ponds during the hottest part of the year, when energy use is highest.
• We’ve taken a conservative approach, excluding yet-to-be-realized efficiencies of scale.

We're also building out a full-year baseline as operations scale, and pursuing a formal, third-party LCA. At the same time, we're conducting an internal LCA with scaled Scope 3 estimates. That means we’re looking far beyond our walls to include the entire value chain.

Emissions Scopes Explained

• Scope 1: Direct emissions from our facilities (e.g., equipment, processes)
• Scope 2: Emissions from purchased electricity
• Scope 3: Everything else, from materials we source (like packaging and gloves) to emissions generated at partner feedlots

So far, our LCA covers Scopes 1 and 2, and our Scope 3 analysis is underway: a critical step as we continue scaling our climate impact.

Building Trust Through Verification and Inclusion

We know that technology is only one piece of the puzzle. Trust requires listening, too.

As we expand, CH4 Global is holding stakeholder meetings with feedlot operators, local First Nations tribes, and informal community stakeholders. These conversations are designed to be:

• Inclusive, ensuring everyone is heard
• Replicable, so we can apply this approach across every future feedlot site
• Streamlined, to make engagement practical and respectful

We make it easy to get in touch with us by email. And while our facilities don’t create major community impacts, we always invite First Nations to be part of the conversation, out of respect for their role as stewards of the land.

Scaling the Impact

This is just the beginning. As adoption grows, Methane Tamer has the potential to prevent gigatonnes of CO₂e from entering the atmosphere. Let’s break it down:

• At 5.6 tonnes CO₂-e avoided per cow (GWP20), 100,000 cows = 560,000 tonnes avoided each year
• Scale to 1 million cows, and the climate benefit becomes 5.6 million tonnes CO₂e annually

This isn’t speculative. The math is real. And with global beef and dairy markets seeking credible ways to cut emissions, the opportunity is massive.

Beyond Seaweed: A More Sustainable Farming Future

Across industries, businesses are recognizing that sustainability isn’t just good for the planet — it’s also good for the bottom line. Increasingly, farmers are also finding that adopting more sustainable practices can lead to greater efficiency, resilience, and profitability.

Seaweed is not a silver bullet, but it’s a powerful tool in the broader climate toolbox, one that delivers immediate, measurable reductions in a sector that has long been difficult to decarbonize. In fact, Methane Tamer is just one of many climate-smart tools available to farmers. Other strategies — from cover cropping and agroforestry to manure treatment — can work together to build a more resilient food system.

Ultimately, reducing methane isn’t just about compliance or carbon credits. It’s about putting real change into practice — and scaling what works — so agriculture can help drive climate progress.

Final Thoughts: Climate Action That Works on the Ground

At CH4 Global, we believe sustainability must be credible, accessible, and measurable. Our work with Methane Tamer reflects that belief: a product backed by rigorous science, delivering meaningful climate impact, and built with the realities of farming in mind.

And we're not just measuring our own success. We're inviting partners, farmers, and communities to help shape what comes next.

Want to know more? Have questions? Reach out. We're here to talk rewriting the climate equation, one cow at a time.