Abstract
Animal agriculture is responsible for 8-10.8% of global greenhouse gas (GHG) emissions as assessed by IPCC accounting and, on the basis of lifecycle analysis, the contribution of livestock is up to 18% of global emissions. Asia is the source of the most enteric CH4 emissions with Latin America, Africa, Western Europe and North America being significant sources. These emissions are dominated by emissions from cattle. When GHG emissions are related to food production, the four most efficient regions are Eastern and Western Europe, North America, and the non-EU former Soviet Union which produced 46.3% of ruminant meat and milk energy and only 25.5% of enteric CH4 emissions in 2005. In comparison, the three least efficient producers (Asia, Africa, Latin America) produced an equivalent amount (47.1%) of ruminant meat and milk energy, and almost 69% of enteric CH4 emissions in 2005. Livestock related emissions will increase as world population and food demand increases; enteric CH4 emissions are projected to grow by over 30% from 2000 to 2020. There are mitigations available now, but it is imperative to develop new mitigations and ways to implement existing technologies more cost effectively.
Generated Summary
This journal article examines the significance of livestock as a contributor to global greenhouse gas emissions, assessing the impact of animal agriculture on climate change and the potential for mitigation. It reviews various estimates of agriculture’s contribution to global GHG emissions, with a specific focus on animal agriculture. The study analyzes the regional distribution of these emissions, their relationship to food production, future emission trends, and possibilities for mitigation at a global level. The research employs data from the Intergovernmental Panel on Climate Change (IPCC), the Food and Agriculture Organization of the United Nations (FAO), and the United States Environmental Protection Agency (EPA), among other sources. The methodology includes a life cycle analysis approach to account for emissions from various stages of livestock production, including feed production, transport, processing, and land use changes. The article also considers the regional distribution of livestock populations and their impact on emissions, as well as projections for future emission trends. The scope encompasses the assessment of current and future impacts and suggests potential strategies for mitigation.
Key Findings & Statistics
- Animal agriculture is responsible for 8-10.8% of global greenhouse gas (GHG) emissions according to IPCC accounting. (Abstract)
- Livestock’s contribution is up to 18% of global emissions based on lifecycle analysis. (Abstract)
- Asia is the source of the most enteric CH4 emissions. (Abstract)
- The four most efficient regions (Eastern and Western Europe, North America, and the non-EU former Soviet Union) produced 46.3% of ruminant meat and milk energy but only 25.5% of enteric CH4 emissions in 2005. (Abstract)
- The three least efficient producers (Asia, Africa, Latin America) produced an equivalent amount (47.1%) of ruminant meat and milk energy and almost 69% of enteric CH4 emissions in 2005. (Abstract)
- Livestock related emissions will increase as world population and food demand increases; enteric CH4 emissions are projected to grow by over 30% from 2000 to 2020. (Abstract)
- Livestock related GHG emission estimates from FAO (2006a) allocated to IPCC emission source category: CO2 (4.26), CH4 (1.8), N2O (0.37), Total (7.26). (Table 1)
- Of the total livestock related emissions of 7.1 billion tonnes of CO2 equivalent (CO2-equiv.), 4.26 billion tonnes, or 60%, would be counted in the agriculture sector by IPCC. (Section 2)
- Livestock related emissions from FAO (2006a) that would be counted in the agriculture sector by IPCC equal 10.8% of global emissions. (Section 2)
- FAO (2006a) estimated that animal agriculture contributes 18% of global GHG emissions. (Section 2)
- FAO (2010) estimated emissions from the global dairy sector to be 4% of the total. (Section 2)
- Table 2 shows the regional distribution of the main ruminant farm animal species: Cattle (1,350,571), Buffaloes (174,526), Goats (821,895) and Sheep (1,090,410) (Table 2)
- Estimates of regional emissions of CH4 from enteric fermentation and manure management, and N2O from manure management and agricultural soils: Total enteric CH4 emissions to be 1929 million tonnes of CO2-equiv., or 91.9 million tonnes CH4 in 2005. (Table 3)
- Global GHG emissions from manure management were 446 million tonnes of CO2-equiv. in 2005 (EPA, 2006). (Section 2.1)
- Production of meat in 2005: 245 million tonnes (30.8% of which was ruminant meat). (Section 2.2)
- Milk production in 2005: 543,347 million tonnes. (Section 2.2)
- Projected demand for all foods, crop and livestock based, will rise by 1.5%/yr to 2030, and by 0.9%/yr thereafter to 2050. (Section 2.3)
- By 2030, food demand will be 156% of 2000 and, by 2050, 186%. (Section 2.3)
- Bovine meat production is expected to have a higher growth rate 2000–2030 (1.3%/yr) than it had in the 1990’s of 0.7%/yr. (Section 2.3)
- Production of milk and dairy produce is expected to expand by 1.4%/yr in 2000 to 2030, up from 1.1%/yr in the 1990’s. (Section 2.3)
- The mitigation potential for agricultural GHG emissions to 2030 was a substantial technical mitigation potential for agricultural emissions of 5500 to 6000 million tonnes CO2-equiv./yr by 2030. (Section 3)
Other Important Findings
- Asia is the source of most enteric CH4 emissions, followed by Latin America, Africa, Western Europe, and North America.
- Emissions are dominated by emissions from cattle.
- The most efficient regions in terms of food production and lower CH4 emissions include Eastern and Western Europe, North America, and the non-EU former Soviet Union.
- Livestock-related emissions are expected to increase due to rising global population and food demand, with enteric CH4 emissions projected to grow by over 30% from 2000 to 2020.
- The study examines regional distributions of emissions and their relation to food production, noting that regional differences in agricultural practices significantly affect GHG emissions.
- The article highlights the importance of deforestation in the context of livestock-related emissions.
- Mitigation strategies include improved feeding practices and management changes.
- Emissions from the livestock sector include CH4 from enteric fermentation, N2O from nitrogenous fertilizers, and CH4 and N2O from manure management.
- The article provides estimates of regional emissions of major agricultural greenhouse gases, including enteric fermentation, manure management, and soils.
- The study notes the relative contribution of different animal types to methane emissions from manure management.
- The main livestock-derived products are meat, milk, and eggs, and the global production of these commodities and their regional distribution are discussed.
- World milk production is dominated by cow’s milk, and egg production is highest in Asia, the Americas, and Western Europe.
Limitations Noted in the Document
- The estimates vary based on the methodologies and data sources used by different organizations (IPCC, FAO, EPA).
- The study primarily focuses on the contribution of animal agriculture, potentially overlooking other significant sources of GHG emissions.
- The analysis relies on projections and estimations, which are subject to uncertainty.
- The article acknowledges that the costs associated with implementing mitigation measures could reduce their practical potential.
- The data used for total global GHG emissions (CAIT, 2010) and livestock related emissions (FAO, 2006a) may not be entirely consistent, leading to some discrepancies in the analysis.
- The study notes that emissions considered do not include emissions associated with land use change, which are relevant for grain-fed meat and milk production.
- Regional differences among individual countries are not discussed in detail.
Conclusion
The study underscores the significant contribution of livestock to global GHG emissions, estimating that animal agriculture is responsible for a substantial percentage of overall emissions. The findings emphasize the regional variations in emission sources and the importance of cattle as a major contributor. The projections for future emissions indicate that, without mitigation, the impact of livestock on climate change will likely increase. The article highlights the necessity of developing new mitigation technologies and adapting current practices to reduce these emissions. Key points include:
- Emissions from the livestock sector are substantial and rising, primarily due to enteric fermentation.
- Asia is the largest source of enteric CH4 emissions.
- Mitigation strategies, while available, require cost-effective implementation to be successful.
- The study’s findings emphasize the complexity of the issue, and the need for a multifaceted approach to addressing emissions from animal agriculture, including technological advancements and adjustments in agricultural practices.