The Meat of the Problem: Farming Without the Footprint
Enteric fermentation is a natural digestive process in ruminant animals like cattle, sheep, and goats. After microbes break down feed into sugars, the sugars ferment and produce methane, which is emitted mostly through burping. Methane is a potent greenhouse gas, with more than 80 times the warming impact of CO₂ over a 20-year timeframe.
The meat, dairy, and fish we consume are major contributors to our warming planet. But what if the world’s food producers could farm in a manner that’s more climate-friendly at every step in the supply chain? Innovators are working on it, and momentum is building. Among the most promising approaches: vaccines and feed additives that limit cow burps; synthetic feeds that bypass emissions-heavy crops; and multi-trophic and circular production models that make aquaculture more sustainable. The challenge is making these solutions cheap, scalable, and effective — not just in high-tech industrial farms, but for billions of livestock worldwide. The goal? A food system that can keep pace with demand without dooming the planet.
Using IPCC and GCAM data, Energy Innovation projected future “greenhouse gas emissions at stake” in 2050, assuming current policies remain in place. The resulting estimates overlap because different technologies may reduce the same emissions pool.
The Path We’re On
Our beef with agriculture today
From a climate perspective, the problem with animal proteins is twofold.
Problem 1: Animal feed
Production of animal feed leads to land-use change that releases large stores of carbon from cleared trees and disturbed soil. That’s compounded by the loss of forest carbon sinks that absorb CO2 over time. Expansion of the land used for grazing livestock further adds to the problem.
Then there’s the fertilizer used to grow massive supplies of soy and other feed, which emits nitrous oxide (N₂O) — a greenhouse gas nearly 300 times more potent than CO₂ over 100 years. Additionally, farm machinery, irrigation systems, and long-haul transport burn fossil fuels. It all adds up to major emissions. In fact, for poultry and aquaculture, feed is the main contributor to GHG emissions (amounting to roughly one gigaton each year).
In recent years, chicken and pigs have seen drastic improvements in feed conversion efficiency (the ratio of calories consumed by an animal to the calories in the food it produces). But beef cows are lagging behind — which means there’s a white-space opportunity to improve feed efficiency for cattle.
Problem 2: Enteric fermentation
Beef is one of the world’s most resource- and emissions-intensive foods. When including land use changes, beef’s GHG emissions per gram of protein are 7 times higher than chicken and 20 times higher than beans. And while land use and feed production contribute, the main driver behind beef’s big footprint is cows’ digestion and waste.
What is enteric fermentation — and why is it a problem?
Enteric fermentation is a natural digestive process that occurs in ruminant animals (such as cows, sheep, and goats), during which microbes in the animal’s stomach break down cellulose and other complex plant materials. One byproduct of this process is methane (CH₄), which the animals release primarily through burping.
Those burps are surprisingly harmful. Methane is a potent greenhouse gas, with more than 80 times the warming potential of CO₂ over 20 years. Enteric fermentation is the largest human-linked source of methane emissions — and a major contributor to global climate change.
Another climate pain point is cow manure. When stored or left in conditions without oxygen (like lagoons, pits, or piles), anaerobic microbes break the manure down. Again, this process releases methane into the atmosphere.
Manure also contains nitrogen, primarily in the form of ammonia and urea. When the manure is applied to soil or decomposes in a field, nitrifying and denitrifying bacteria turn some of it into nitrous oxide — another particularly potent greenhouse gas.
Today, there are 1.5 billion cows alive on Earth. That’s a lot of burps, a lot of manure — and a lot of emissions.
A New Way Forward
Still on the table: how can we make animal proteins climate-compatible?
It’s all enough to make us rethink our burgers — but eliminating meat from our diets is just one way to shrink agriculture’s climate footprint. There are a number of promising new methods that aim to lower emissions intensity per unit of protein, particularly in the high-emission beef industry.
These are, we believe, the most viable pathways to more climate-friendly animal and fish production.
Innovation Imperatives
Reduce enteric emissions in ruminant animals through microbiome intervention, feed additives, vaccines, or other methods
Innovators have found a number of ways to reduce methane emissions from enteric fermentation, from natural or chemical feed additives to vaccines to microbiome intervention. While reductions are helpful, elimination or near-elimination would be a gamechanger. To be truly scalable, solutions need to be ultra-low-cost, applicable to both grazing and intensified livestock operations, and ideally provide economic value in the form of health or productivity improvement.
Scale climate-efficient fish and seafood production that displaces high-emissions animal protein
Aquaculture is the fastest-growing source of animal protein in the world — and, if done right, one of the most climate-efficient. Fish and seafood can deliver high-quality protein with a far lower footprint than beef or dairy. This imperative focuses on developing and scaling low-emissions aquaculture systems — including alternative and seaweed-based feeds, multi-trophic and circular production models, and other feed and system innovations — that reduce reliance on soy and fishmeal, cut lifecycle emissions, and improve farm economics.
Moonshots
Invent new sources of affordable, scalable livestock feed that are entirely decoupled from land use
Innovation is already making it possible to move beyond conventional feed crops like corn and soy. Approaches include improving existing feed formulations (for instance, by extending shelf life, enhancing digestibility, and reducing fermentation) and introducing novel ingredients (such as algae, insect meal, single-cell proteins from gas fermentation, and targeted prebiotics and probiotics). But the real moonshot lies in completely decoupling animal agriculture from crop-based feed. This would require breakthroughs in biomanufactured fats and volatile fatty acids — essentially “food without photosynthesis” — could slash the land, water, and fertilizer demands of feed production while improving animal health and productivity.
The most viable solutions will:
The solution must be net-positive to a business’ bottom line, providing tangible returns through improved productivity, yield, and/or animal health. Practically, that means enteric emissions solutions should cost less than $0.10 per head per day, while feed alternatives need to be cheaper than current options and deliver added benefits — like higher yields or healthier animals — to ensure a strong profit incentive for producers operating on razor-thin margins.
Any solution must integrate seamlessly into existing operations, with low upfront capital expenditure and minimal disruption to feed and animal management schedules.
Inputs must be producible at a massive scale; and, in the case of new types of feed, must be able to generate enough calories and the right macronutrients to supply a significant portion of the global herd. Supply chains must also be resilient — able to withstand price volatility, climate shocks, and geopolitical disruption — to ensure long-term reliability for producers.
New approaches will need to grapple with the fact that most of the world’s cattle aren’t kept in confined spaces, but out in fields, grazing. Solutions must be deployable across all major production systems, including intensified feedlots, free-range grazing, and smallholder farms.
Solutions must have the potential to mitigate a majority of the target emissions (e.g., >50% of enteric methane).
The upstream emissions from producing and deploying the solution — including land use, energy, fertilizer, and transport — must be lower than current options. Full lifecycle assessments are essential to ensure that apparent gains at the farm level do not create hidden emissions elsewhere in the system.
