Greenhouse Gases Emission from Livestock Production

Greenhouse gas (GHG) emissions from livestock production refer to the release of carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) generated throughout the entire livestock supply chain, including feed production, enteric fermentation, manure management, processing, and transports. Livestock farming systems contribute considerably to global anthropogenic greenhouse gas emissions. In this context, livestock production is an important source, and published estimates vary depending on the calculation methodology, system boundaries, and climate parameters used. Carbon dioxide emissions are mainly associated with the use of fossil fuels in feed production, energy consumption, processing, and land use change. Methane comes primarily from enteric fermentation in ruminants and anaerobic manure storage. Nitrous oxide derives from nitrification and denitrification processes that occur during manure storage and after application to the soil. The quantification of GHG emissions related to livestock is commonly conducted using life cycle assessment (LCA), which evaluates emissions from the cradle to the farm gate or from the cradle to retail. The reported emission intensities vary considerably depending on the species, production system, geographical context, system boundaries, and carbon accounting parameters. GHG emissions from livestock production must be considered as the result of complex biological, technological, and management interactions operating within integrated agroecosystems.