Complex But Critical: The pathways for short-lived climate pollutant mitigation in the agriculture sector

by CCAC Secretariat - 26 March, 2024
The latest in our sectoral Q+A series – a discussion with Gregory Kohler, Agriculture Expert, Climate and Clean Air Coalition Secretariat at UNEP

Where do the various existing options stand in terms of potential to reduce methane emissions in the agricultural sector?

Livestock and rice are the two largest emitters of methane in agriculture, accounting for approximately 32% and 8% of total emissions, respectively. –  There are several solutions available, some of which are technological, while others are logistical or management-based.

Solutions like feed additives that we hear about in the news are not yet fully developed and ready for implementation in most farm contexts.  These solutions hold a lot of promise in being able to reduce the production of methane in cows’ digestive tracts, but they still require research and regulatory approval. Once they are approved, feed additives will primarily work in concentrated production systems where cattle have controlled feed rations. Despite the frequent news about these initiatives, they aren’t yet ready to implement and are mostly suitable for rich country systems.

Solutions for low- and middle-income countries should focus on best practices in land and animal management. These solutions safeguard incomes and food security while helping farmers adapt to the impacts of changing climate already being seen globally. In East Africa for example herders are already changing their herd composition to have more goats and camels. 

There are breeding programs to select for higher yielding and disease-resistant livestock, and even breeding for lower methane emissions. Better animal health can also contribute to herd resilience and reduce methane intensity through reduced mortality. A better-fed and healthier cow gains weight faster and will provide more meat or milk over its lifetime.

What are the challenges in coordinating private and public stakeholders in agriculture?

The range of stakeholders in the livestock sector adds complexity to coordinating solutions to progress towards implementing solutions at scale. The structure of each sub-sector makes a difference. 

For example, the dairy industry is often organised through cooperatives, so it's easier to align the incentives of the farmers with the consumers. The dairy industry already has well-defined ways of paying farmers for the quality of the milk per litre. In theory you could add in a climate benefit into those payment systems if farmers are producing milk at a lower methane intensity. We have also seen large multinationals in the dairy industry shift to align the industry with the commitments of the Global Methane Pledge – so a 30% reduction in methane by 2030 from the dairy sector. 

In other sectors such as beef, it's harder to find those alignments across the value chain because there are fewer cooperatives, so it's a more fragmented sector.

If industry coordination and food security pressures make it hard to limit per-head livestock emissions, where do land use impacts factor into potential mitigation of the greenhouse gas impact of agriculture?

The biggest source of carbon emissions from agriculture is deforestation, especially in tropical forests, which store and sequester a lot of carbon. This is countries like Brazil focus on sustainable intensification without expanding land use for cattle production. But it must come with implementation of regulations to protect natural areas, because more efficient agriculture becomes more profitable and incentivizes farmers to increase the amount of production.

One of the unique things about agriculture is that because it has that direct link to carbon sequestration in terms of land use. Understanding exactly how much carbon can be sequestered is still a challenge, but we know that silvopastoral systems – where tress are incorporated into a pasture landscape – can have a huge benefit for animal welfare, carbon sequestration, water resources management, and erosion.

Silvopastoral systems can also be more productive because of their higher water retention meaning grasses survive through droughts and provide better feed for cattle. However, the calculations linking the overall carbon sequestration and methane impact require more research. When we look at all options for increasing livestock efficiency, sequestering carbon and directly reducing methane we must balance short-term and long-term priorities.

Some countries like Brazil are combining these priorities by looking at rehabilitating degraded pastureland and encouraging farmers to store carbon through better land management instead of expanding pastureland by clearing forest. This includes using crop, livestock and forest integration where fast growing trees can be used for wood production, with crops and livestock all coexisting in the same land. Trialling and proving the viability of these practices in Brazil also helps scale them in other tropical countries.

One major challenge we see across other sectors emitting short-lived climate pollutants is gathering the finance to implement solutions. What are the financing challenges in agriculture, and where do carbon credit schemes fit in?

In agriculture there are large discrepancies in the financial situations of different stakeholders. For example, there are small holders and pastoralists who are struggling to make a living through livestock and then you have big ranches and conglomerates that are extremely profitable. The former are very vulnerable to market and environmental shocks and are the ones who need the most financial support. One challenge is that soil carbon is very hard to measure, and the work on establishing credits for soil carbon is still in development.

Direct methane emissions are currently hard to link with carbon credits, but the widespread rollout of technologies like feed additives would make it easier to link to carbon markets. In the agriculture sector the focus is still on carbon sequestration through sustainable agroforestry, as it is easier to measure carbon sequestration from trees.

Because agriculture is a profitable industry, one challenge we have is that more efficient agriculture incentivises more agricultural production and more livestock consumption. But the picture is not even across countries. In the global south a lot of meat consumption is below WHO recommendations of animal source food. Increases in efficiency will help meet the dietary needs of those populations and be a net benefit for society in food security, even though it may increase overall methane. This contrasts with the global north where meat is often over-consumed.

Results-based payment mechanisms also present a promising approach to catalyse action that indirectly reduces emissions intensity via improving animal health and productivity. These are essentially demand-side incentives, encouraging farmers and market system stakeholders to adopt practices that increase feed supply, drive sustainable intensification, and increase productivity, thereby reducing emission intensity.

Results-based payment mechanisms can address market gaps and support scaling of proven technologies. In the case of fodder production there is high demand but inadequate supply, so results-based payments can stimulate and de-risk investment by offering premiums for each bundle of hay produced. By reducing input costs and developing better distribution networks, these payment systems can draw in additional actors, helping to scale change across the market system until there is a critical mass of market change and subsidies can later be withdrawn.

So far we have only spoken about cattle, but rice is also an important sector for reducing methane. What is the status of methane reduction efforts in the rice sector?

In rice cultivation the solutions are not about increasing the efficiency of production so much but reducing absolute methane emissions.

Permanently flooded rice paddies generate methane-producing bacteria. Water management changes in flooding patterns which enable them to dry out periodically can interrupt the bacterial growing cycle and drastically reduce emissions. These interventions are particularly suitable for rice grown in deltas where it is hard to stop water flows. One tradeoff in these interventions is the release of nitrous oxide emissions when the paddy is dry.

Farmers struggle to take up alternate wetting and drying even though there are clear benefits in terms of the methane emissions reductions. This is because there's it is more labour intensive, and a lot of farmers don't see the benefit. Even though it is supposed to increase yields, the farmers don't necessarily see that benefit directly.

Also, farmers are not often incentivised to use less water because they pay a set amount of money for access to water instead of paying a per-litre price. It is hard to change the structures because most smaller farmers are already facing a lot of financial challenges – so making water use more expensive makes it a lot harder for them to produce the crops. Removing water subsidies and making farmers pay per unit of water would incentivize alternate wetting and drying.

What about ownership structures in rice cultivation, is it a much harder collection of stakeholders to manage?

Rice cultivation is very decentralised among smaller farmers. It tends to be less than a hectare of land per farmer. This means a lot of rice farmers do other work because it's such a small amount of land and it is often a supplement to other income. As the alternate wetting and drying cycle approach is more labour intensive this also adds to the burden on smallholder farmers. It is a big ask for the farmer to spend more time managing the irrigation of rice, which is already competing with the time needed to generate other income streams.

The agriculture sector in general is also a quickly ageing workforce and so it's also harder to implement change because a lot of producers have been growing rice the same way for 30 years and it's harder for them shift away from the traditional methods. Innovations tend to be taken up most by youth and the agriculture sector is losing youth to other sectors.

We know that other forms of waste have the potential for circular economy value adding. Is there much potential for circular economy solutions in the agriculture sector?

In agriculture, managing nutrient cycles is central to the potential for a circular economy. With both animal manure and other agricultural residues such as rice straw husks, the main challenge is the logistics of managing the materials. They are often very heavy, centralised, and far away from where they are needed.

Even when there's a lot of demand for fertiliser, it's hard to bring manure to the areas where you need the fertiliser. Distributing natural fertiliser would reduce the demand for synthetic fertilisers produced from natural gas, and which increase our reliance on the fossil fuel industry. That would make the use of natural fertilisers a double win for emissions reductions. But to do that we have to develop profitable distribution logistics.


It’s a similar case to reducing crop burning. There are ways you can bring crop residues into alternative value chains. Turning it into compostable materials for example is one opportunity – some of those alternative plastics that you see are made from crop residues. There are also attempts to pelletize residues to create high-quality animal feed when mixed with other nutrients. There are still a lot of challenges in logistics and making these schemes profitable beyond the pilot phase, however.

An ideal option is finding ways to integrate it into the soil so that you're using it to increase the fertility of the crops rather than burning it. The challenge with this solution is usually that there's a very short time between crop harvesting and the planting of a new crop. Burning is often the quickest and easiest way to deal with the residue – particularly in South and Southeast Asia where the crop cycles are short. We need to support ongoing work to incentivize no-till agriculture.

It seems there is a need for some solutions to be centralised and scaled up, and for some to be decentralised to the local level. Are there any models which so far manage to balance the challenges of scale in agriculture?

Centralised solutions can reduce the climate impact because large-scale actors can implement scalable solutions for more efficient production. But centralisation also introduces problems where smaller farmers are even more marginalised in the system and have less access to resources and have difficulty maintaining their livelihoods.

Then there are other environmental and health challenges of centralisation such as manure lagoons, which can spill over into the local ecosystem, and it creates all kinds of other problems for communities. Concentration provides a more profitable business case, but can create many negative externalities.

Pollutants (SLCPs)