Various mitigation options exist to reduce greenhouse gases while meeting increased demand for terrestrial animal-sourced foods

It is imperative to chart pathways to lower the greenhouse gas emissions produced by the world's livestock systems in the face of a growing global population and a projected 20 percent increase in demand for terrestrial animal products by 2050.

Pathways towards lower emissions - A global assessment of the greenhouse gas emissions and mitigation options from livestock agrifood systems https://doi.org/10.4060/cc9029en, released Friday on the sidelines https://foodpavilion.org/blog/programme/less-emissions-with-better-livestock-production-climate-solutions-for-sustainable-livestock-transformation/ of the UN Climate Change Conference COP28 https://unfccc.int/cop28 climate summit, raises the bar of opportunity for policy makers, industry participants, smallholders and consumers.


"Beyond evaluating baseline emissions, this report offers estimations of future emissions under scenarios of increased production and outlines pathways to reduce emissions through the application of well-established best practices in animal management. It clearly demonstrates that ambitious and innovative programmes and wide-ranging interventions have the potential to bend the emissions curve while production grows," said FAO Deputy Director-General Maria Helena Semedo.


"Solutions such as improving animal health, breeding practices, reducing food loss and waste, and directly targeting GHG emissions have the potential to provide multiple benefits for people and the planet, but they require investments in the sector to narrow efficiency gaps, while meeting an increased global demand for animal protein," she added, noting that interventions must be site specific, facilitate farmers' access to finance and services to enable them to implement tailored interventions.


The report, subject to a double-blind peer review process involving world experts, outlines several pathways impacting both the supply and demand sides for livestock sectors, which, if adopted collectively, could address the environmental impacts and promote sustainability. While there is no universal solution and more work is needed to understand the barriers to implementing and upscaling these interventions, enhancing productivity and production efficiency across the entire value chain is the most promising way to mitigate and reduce livestock emissions.

Facts and figures

In 2015, livestock agrifood systems, including on farm production activities and some key supply chain processes such as land use change related to feed, transport and input manufacturing, accounted for approximately 6.2 billion tonnes of CO2 equivalent emissions (GtCO2eq) per year, equal to around 12 percent of all anthropogenic GHG emissions and about 40 percent of total emissions from agrifood systems, estimated by FAO https://www.fao.org/food-agriculture-statistics/data-release/data-release-detail/en/c/1661912/ at about 16 GtCO2eq. Without interventions and productivity gains, meeting increased demand is likely to bring global livestock emissions to nearly 9.1 GtCO2eq by 2050.


The figures are derived from the Global Livestock Environmental Assessment Model (GLEAM https://www.fao.org/gleam/resources/en/), an innovative FAO tool that adds significant value and opportunities to support better analyses of mitigation pathways. Using a geospatial framework, GLEAM can analyze activity data from different livestock production systems around the world and calculate their carbon footprint at various scales and for different sources.


GLEAM uses a life cycle assessment approach spanning emissions associated with raising animals, including enteric fermentation, as well as indirect emissions stemming from upstream activities such as provision of feed and other inputs, and part of the downstream processes including post-farm transport, processing and packaging of raw products. It does not cover the retail and household stages.


For the first time, the FAO report usefully compares the GLEAM estimates with the independent livestock-related emissions that are part of FAOSTAT https://www.fao.org/faostat/en/#data/GT's agrifood systems emissions data. An item-by-item comparison of relevant emission processes shows that the two data frameworks provide consistent estimates of emissions levels, with FAOSTAT offering a more comprehensive agrifood systems approach, whereas GLEAM allows users to perform far more detailed analyses of mitigation options in livestock systems.

Some data highlights include the finding that cattle - including meat and milk - contribute around 3.8 GtCO2 equivalent per year, or 62 percent of the livestock total, while 14 percent are attributed to pigs, 9 percent to chickens, 8 percent to buffaloes and 7 percent to small ruminants. By commodities, meat production accounts for two-thirds of the emissions, milk 30 percent and eggs the rest.


Direct emissions, including methane from enteric fermentation by ruminants and nitrous oxide from manure management systems, account for 60 percent of the sector's total emissions, with the rest stemming from the manufacture of fertilizers and pesticides for feed production, feed production itself, as well as processing and transportation of feed, live animals and livestock products, and land-use changes associated with feed production.


Overall, methane is slightly more than half the total, and its spatial distribution closely tracks the location of ruminant herds, whose digestive systems produce methane from a diet of mostly grasses that humans cannot digest. For monogastric species such as pigs and chickens, emissions primarily stem from feed production and manure management.


The GLEAM tool allows the report to dive down into the significant disparities in the carbon footprint or emissions intensity of one unit of milk, meat or eggs across countries, species and production systems, which reflect local issues and often the most promising mitigation potential. The range of average emission intensity of cattle milk in grassland systems varies by a factor of 20, and in one study of smallholders in Kenya, by a factor of 50 for bovine meat. It is in that variance that mitigation efforts can bear the most fruit.


The results of the report, together with some key input data and related information are available on the GLEAM dashboard https://www.fao.org/gleam/dashboard/en/ that offers a set of tools to explore the data interactively.

While investments to embark on concrete actions to mitigate livestock emissions must be accelerated, FAO will further improve the GLEAM platform so that it can provide on-demand simulations online and allow users to immediately gauge the impact of implementing different interventions under different scenarios on certain environmental indicators.

Mitigation goals

The report https://doi.org/10.4060/cc9029en aims to enable the livestock sector to contribute its share to the efforts to limit the global temperature increase to well below 2 degrees Celsius.

Options to produce more with less emissions are available for all regions and production systems.


To maximize the mitigation potential, it is crucial to facilitate farmers' access to services and invest in enabling their ability to implement tailored interventions.

Moreover, mitigation strategies must both be tailored to local circumstances and be holistically integrated into broader programmes that support rural resilience and livelihoods as well as other sustainability goals.

Adopting best practices - including agroforestry https://doi.org/10.4060/cc2280en and optimized rotating grazing - on all grasslands globally could harness sequestration capacity enough to knock off nearly one-third of the livestock's current annual emissions, but the economics of such a change may not be viable in the short to medium term.


Likewise, replacing a share of a pig's diet with swill from household waste can lead to dramatic reductions in overall nitrogen emissions, would require appropriate investments in infrastructure, policies and regulations to ensure feed safety and reduce the risks of triggering animal disease outbreaks as occurred with African swine fever in Asia recently.


Some proven mitigation solutions, such as advanced breeding and feed mixtures - including novel feed additives - may not be suitable everywhere due to cost, safety, and accessibility issues. Grassland-based systems, for instance, are unlikely to benefit from strategies designed for housed systems. Moreover, the mitigation effects of reducing consumption of animal-based foods will depend on what replaces them.

Boosting animal health is a robust approach to increasing livestock production efficiency and, by increasing the availability of animal protein without requiring larger herds or flocks. Healthy livestock have higher yields, an important channel to reducing their emissions intensity.

In the framework of its Sustainable Livestock Transformation Initiative, FAO supports countries in transitioning to a sustainable livestock sector, taking into account the diversity of livestock production systems by developing and implementing sustainable and accessible animal production and health solutions to increase productivity, mitigate greenhouse gas emissions, adapt to climate change and improve health.