We’ve all heard of methane, a greenhouse gas whose emissions significantly contribute to climate change. Its global warming potential is about 28 times greater than that of carbon dioxide (CO₂) over a 100-year period, as noted in the IPCC Fifth Assessment Report (AR5).
Agriculture is one of the largest sources of methane emissions (46% of the total), with livestock production being a major contributor. Methane is primarily released through enteric fermentation, a natural process that occurs in the digestive system of ruminants such as cows, sheep, and goats. During digestion, microorganisms in the rumen (one of the compartments of these animals’ stomachs) break down fibrous food, producing methane (CH₄), which is mostly expelled through belching. Approximately 55-60% of methane emissions in agriculture originate from this process.
Manure management accounts for 6% to 8% of agricultural methane emissions, though some studies suggest the figure may be significantly higher. In large-scale dairy and pig farming operations, manure is often removed using water jets and stored in tanks or lagoons in liquid or semi-liquid form. These moist environments create ideal conditions for methane-producing microorganisms to thrive. In contrast, small and medium-sized farms, where manure is typically stored in solid form or sun-dried, emit significantly less methane.
Another important factor is rice cultivation in flooded fields, responsible for 8% to 20% of agricultural methane emissions. This happens because the constant presence of water prevents oxygen from entering the soil, creating an ideal environment for anaerobic bacteria that break down organic matter, releasing methane in the process. The gas then disperses into the atmosphere through the water and rice plants themselves. Since methane has a much stronger short-term climate impact than CO₂, flooded rice farming is a major global source of methane emissions.
How can methane production be reduced?
Recently, various initiatives and studies—such as those published by the World Resources Institute (WRI)—have highlighted innovative solutions to reduce these emissions.
One of the most promising ways to cut methane emissions in livestock farming is to prevent its formation during digestion. Researchers have developed methane-inhibiting feed additives, which can significantly reduce methane production. The synthetic compound 3-NOP (3-nitrooxypropanol), for example, can reduce emissions by about 30% and has already been approved for use in beef and dairy cattle in over 60 countries. However, its adoption faces challenges, including high costs and acceptance among farmers and consumers.
A natural alternative under study is red seaweed (Asparagopsis), which has shown about 30% effectiveness in long-term trials. However, extracting its active compound, bromoform, raises public health concerns and presents scalability challenges for large-scale production.
Beyond feed additives, selective breeding for low-methane-emitting cattle is emerging as a strategy with long-term impact. Studies indicate that some cows naturally emit up to 22% less methane than others, and these traits can be passed down through generations. Pilot projects in Canada and New Zealand are currently testing this approach, but more research and farmer education programs are needed.
Another emerging technology is methane-reducing vaccines, which are in the experimental phase and could reduce emissions by around 30%. If successful, these vaccines could have significant global adoption potential, as they could be integrated into existing livestock vaccination programs.
For manure management, biogas production has been widely promoted as a solution, converting methane into energy. However, high costs, the risk of methane leaks, and potential water quality impacts raise questions about its true environmental effectiveness. Alternative methods, such as solid-liquid manure separation, can reduce emissions by up to 60% at a lower cost. Another promising technique is manure acidification, which inhibits methane production and has already been adopted in Denmark, reducing emissions by up to 89% in tests.
For rice farming, alternative water management techniques—such as intermittent flooding instead of continuous submersion—have proven effective in reducing methane emissions without compromising productivity. Additionally, better management of organic residues and composting agricultural waste are being explored as viable solutions to lower the environmental impact of farming activities.
The tole of policy and innovation
The WRI emphasizes that achieving significant methane reductions requires a combination of technological solutions, supportive public policies, and financial incentives for farmers. Studies indicate that investing in methane mitigation technologies can yield short-term benefits, as methane is a short-lived pollutant. This means that reducing its emissions could lead to rapid improvements in global warming rates.
Beyond technological advancements, knowledge-sharing between farmers, scientists, and policymakers is crucial. Collaboration across these sectors can help tailor best practices to local conditions, contributing to more sustainable and resilient agricultural systems.
A path to sustainable agriculture
Reducing methane in agriculture is a key element in the fight against climate change. Initiatives that combine changes in livestock feed, improved water management in rice fields, and better agricultural waste handling provide a promising pathway for emission reductions. With strong public policies and financial incentives, these solutions could transform the agricultural sector, promoting not only environmental sustainability but also economic and social development in rural communities.
