Agriculture will have to double the production of food in order to nourish 9 billion people in 2050 while the need of reducing the environmental harm will become ever more pressing. Globally, about half of the value of agricultural output is related to livestock and is being recognized as one effective contributor to rural poverty alleviation.
The Global Livestock Environmental Assessment Model (GLEAM) simulates the main stages of livestock production using a life cycle assessment (LCA) approach. The use of LCA methodologies in the evaluation of complex scenarios, such as agricultural production, has risen in the last years. An important strength of LCA is the ability to perform a systematic and comprehensive analysis of the system. It allows the identification of environmental burdens and the potential effects of interventions. The latter aspect is essential to detect those options that would merely shift impacts along the chain.
GLEAM provides a detailed, spatially explicit simulation of animal populations’ distribution and their main edible products for six species: meat and milk from cattle, buffaloes, sheep and goats, meat from pigs and meat and eggs from poultry. The model uses georeferenced climatic data and feed yields, allowing the analysis of local drivers and constraints of animal production. The current version of GLEAM focuses on the quantification of GHG emissions, namely methane (CH4), carbon dioxide (CO2) and nitrous oxide (N2O), using Tier II methodology in animal derived emissions from enteric fermentation and manure management. This feature enables a more accurate information on how feeding and manure management options can be used for mitigation.
May 2015/ FAO.