Livestock contribute both directly and indirectly to climate change through the emissions of greenhouse gases such as carbon dioxide, methane and nitrous oxide.
Globally, the sector contributes 18 percent (7.1 billion tonnes CO2 equivalent) of global greenhouse gas emissions. Although it accounts for only nine percent of global CO2, it generates 65 percent of human-related nitrous oxide (N2O) and 35 percent of methane (CH4), which have 296 times and 23 times the Global Warming Potential (GWP) of CO2 respectively.
Methane emissions mostly occur as part of the natural digestive process of animals (enteric fermentation) and manure management in livestock operations. Methane emissions from livestock are estimated at about 2.2 billion tonnes of CO2 equivalent, accounting for about 80% of agricultural CH4 and 35% of the total anthropogenic methane emissions.
Nitrous oxide emissions are associated with manure management and the application and deposition of manure. Indirect N2O emissions from livestock production include emissions from fertilizer use for feed production, emissions from leguminous feedcrops and emissions from aquatic sources following fertilizer application. The livestock sector contributes about 75 percent of the agricultural N2O emissions (2.2 billion tonnes of CO2 equivalent).
Carbon dioxide emissions from the livestock sector are related to fossil fuel burning during production of fertilizer for feed production, the livestock production process, processing and transportation of refrigerated products. Furthermore, livestock are a major driver of the global trends in land-use and land-use change including deforestation (conversion of forest to pasture and cropland), desertification, as well as the release of carbon from cultivated soils. The overall contribution of CO2 emissions from the livestock sector are estimated at 2.7 billion tonnes of CO2.
These estimates on the sector’s role in climate change are a result of LEAD’s efforts to quantify the sector’s impacts at a global scale. More detailed analysis is required to shape policies that can effectively mitigate environmental impact at every relevant step of the various commodity chains, and help adapting to climate change.
To-date, activities are geared towards expanding this initial assessment focusing on:
Activity 1: Assessing the contribution of various animal species and livestock production systems to GHG emissions using the Life Cycle Assessment approach. This activity supports the expansion of the knowledge-base and refinement of emission quantification methodologies related to GHG emissions from the sector with the objective of facilitating better understanding of the sector’s impacts, taking into account the differences across production systems and species.
Activity 2: Identification of GHG emission hotspots along the food chain to facilitate effective design and targeting of mitigation options.
Activity 3: Assessment and development of policy options for GHG emission reduction from the sector. The activity explores how global mitigation policies could generate significant changes in the global geography of livestock production, trade and consumption and policy options for cost-effectively managing the sector’s growing contribution to GHG emissions.
Activities on climate change are organized around three main projects:
Greenhouse gas emissions from the animal food chain
Making agriculture part of the solution to climate change – Building capacities for Agriculture Mitigation
Global economic analysis of climate change policies for livestock.
Note: For this post, text and image taken from http://www.fao.org/agriculture/lead/themes0/climate/en/