Livestock are crucial to the livelihoods of at least 1.3 billion people, particularly in low- and middle-income countries. For many of the 400 million resource-poor livestock keepers, animals are their major asset, and consumption of meat, milk and eggs are essential for the health and nutrition of many vulnerable groups, particularly young children, pregnant women, and older adults. While consumption of meat and milk in these countries is much less than that in Europe and North America, demand – and emissions – are forecast to grow substantially, mainly through population and income growth.
That’s a challenge because livestock already contribute 38 percent of global agricultural land emissions – from methane-produced during digestion and manure. Indirect emissions – from feed, energy and land use change – contribute an additional 26 per cent. Without addressing livestock emissions, it may be impossible to meet global climate policy targets.
Can livestock be sustainable?
Simply, yes – and in some cases, they already are. The world’s rangelands – grasslands, savannas and woodlands too marginal for crops – have been sustainably managed by herders for millennia.
Mixed crop-livestock systems are another example, with animals providing manure to fertilise crops, and crop residues providing feed for the animals. These systems can have multiple benefits: sustainably increasing production, incomes and resource use efficiency while sequestering carbon and enhancing soil fertility, and supporting biodiversity, for example. They already produce nearly half of the world’s cereals and most of the staples consumed by resource-poor people, as well as generating the bulk of the meat and milk produced in lower-income countries.
Can methane production from livestock be reduced?
Methane has a global warming potential 28 times greater than carbon dioxide. But its relatively short atmospheric lifetime means its reduction is one of the fastest ways to achieve near-term climate benefits. Innovations to reduce methane from livestock, therefore, present significant opportunities, and they include:
- Low-emitting livestock: using natural genetic variation in methane production traits to breed livestock that emit less methane. This can be done by incorporating methane and microbiome traits into breeding indices.
- Anti-methanogen vaccines: administered to livestock, these prevent or reduce enteric methane production. Approaches include targeting whole methanogen cells or the specific enzymes and proteins involved in methane production.
- Rumen microbiome inhibition: approaches include modifying the genes that control methanogenesis, introducing bioengineered gut microbes while the animal is young to reduce methane emissions for the rest of its lifetime, and introducing slow-release methane-inhibiting capsules that biodegrade in the rumen.
- Feed formulation: many feed additives have been shown to reduce methane emissions, with 3-Nitrooxypropanol (a synthetic compound) and red seaweed proving particularly effective. Precision technologies that automate feeding at the individual animal level are also being adapted to optimise feed allocations and reduce emissions.
Other innovations aim to remove methane once it has been produced, like methane-eating microbes – specialised bacteria that consume methane as their primary energy source. Special masks worn by animals can capture and neutralise exhaled methane produced during enteric fermentation. Nanoshell catalysts – still in early stages of development – are specialised materials that could be used to capture methane emitted from livestock housing, manure management facilities, or biogas plants, and convert them into feedstocks like methanol and hydrogen, which can be reused as fuels or industrial inputs.
What’s next?
There are no guarantees that total emissions will be reduced even if some of these innovations are adopted at scale: some farmers may increase herd sizes because of increased production efficiency and greater demand for livestock products as consumer prices drop – the Jevons paradox. And the history of agricultural innovation tells us that with any new technologies there are always winners and losers, with the benefits usually very unevenly shared due to issues of access and affordability. In other words, they could make the rich richer while the poor face exclusion.
That’s why the future of sustainable livestock will depend as much on governance – the way the innovations are introduced and supported – as on science. Both public and private financial support will be required to lower risks and costs. Funders and governments can help by redirecting subsidies and enabling innovative financing models – such as “patient capital”, which offers long term, flexible terms to give new technologies time to mature.
In addition, regulations will need to provide timely approval of proven technologies, while safeguarding health and the environment. Governments may need to strengthen extension services to support livestock farmers to adopt new technologies and expand insurance schemes and other safety nets. If livestock farming is no longer viable for some, social protection measures coupled with vocational training for other work will be essential.
As a critical component of the food system, reconfiguring the livestock sector for sustainability, equity and health outcomes is one of the defining challenges of the age. Rather than an oxymoron, it should be the plan.
Header photo credits: ILRI/Stevie Mann
