Diseases affecting animals, how long they live and how productive they are all have a significant impact on greenhouse gas (GHG) emissions, according to a report published jointly by the Food and Agriculture Organization of the United Nations (FAO), the Global Dairy Platform and the Global Research Alliance on Agricultural Greenhouse Gases.
The authors of the study point out that greater investments are needed in order to establish measurement, reporting and verification (MRV) systems. There is currently no standardised method for including improved animal health in most countries’ GHG national inventories or nationally determined contributions (NDCs). As a result, the importance of animal health is often not clearly reflected in their climate change commitments.
The report The role of animal health in national climate commitments published in July 2022, shows how countries can develop MRV systems at national level that would enable improvements in animal health to be included in national climate commitments.
However, the report also points out that in order to achieve this, countries would need to use the detailed methodologies known as Tier 2 or 3, developed by the Intergovernmental Panel on Climate Change (IPCC).
While GHG emissions per animal are estimated solely on the basis of regional averages in the commonly used Tier 1 approach, Tier 2 looks at specific local production systems. This includes herd parameters (e.g. mortality, fertility, age at first parturition and replacement rate) for estimating the impact on animal numbers as well as production data, including milk yields and animal weights at different life stages.
Data on feed for different categories of animals and manure management systems are also critical, as these have a considerable influence on emission factors. Measuring parameters, such as the methane (CH4) conversion factor, may even require the use of Tier 3 approaches, which in turn would call for more complex modelling and the corresponding data, the report says.
Deciding how livestock emissions are reported in national GHG inventories and included in NDCs presents a major challenge. In their inventories, countries report direct emissions at sector level. In the livestock sector, these include CH4 emissions from enteric fermentation in the animals’ digestive systems and CH4 and nitrous oxide (N2O) emissions released in the manure management process. Emissions from feed production, processing and transport as well as energy use are reported under either “agricultural soils” or “energy sector”.
At the same time, animal health interventions cannot be considered in isolation solely in terms of their impact on direct emissions at animal level. For example, supply-chain emissions may diminish due to the reduced need for replacement animals or changes in the feed ration. It is therefore important to adopt a systems perspective and to understand the drivers of supply-chain emissions.