Generated Summary
This report presents an assessment of greenhouse gas (GHG) emissions from the global dairy cattle sector, conducted by the Food and Agriculture Organization of the United Nations (FAO) in collaboration with the International Dairy Federation (IDF). The study utilizes a Life Cycle Assessment (LCA) approach to estimate and analyze GHG emissions associated with milk production, processing, and transportation across different regions and farming systems. The methodology involves a cradle-to-farm-gate approach, encompassing the entire dairy food chain from feed production to the final processing of milk and meat. The assessment aims to provide insights into GHG emissions, identify hotspots, and support efforts to improve the sustainability performance of dairy farming. The study focuses on major greenhouse gases: carbon dioxide, methane, and nitrous oxide, while excluding emissions related to land use under constant management practices, capital goods, on-farm milking and cooling, and retail stage activities. Numerous assumptions and simplifications were made due to data limitations, necessitating a sensitivity analysis to determine the results’ accuracy.
Key Findings & Statistics
- The global dairy sector emitted 1,969 million tonnes of CO2-eq [±26 percent] in 2007. Of this, 1,328 million tonnes were attributed to milk, 151 million tonnes to meat from culled animals, and 490 million tonnes to meat from fattened calves.
- The global dairy sector contributes 4.0 percent to total global anthropogenic GHG emissions [±26 percent].
- The overall contribution of global milk production, processing, and transportation to total anthropogenic emissions is estimated at 2.7 percent [±26 percent].
- The average global emissions from milk production, processing, and transport is estimated to be 2.4 CO2-eq. per kg of FPCM at the farm gate [±26 percent].
- Average regional emissions, per kg of FPCM at the farm gate, range from 1.3 to 7.5 kg CO2-eq. per kg of FPCM [±26 percent].
- In comparing the total average life cycle emissions across different world regions, the highest emissions per kg of FPCM were found in developing regions with sub-Saharan Africa, South Asia, North Africa, and the Near East, with averages of 7.5, 4.6, and 3.7 kg CO2-eq. per kg of FPCM, respectively.
- Industrialized regions such as North America and Europe, on the other hand, were found to exhibit the lowest emissions per kg of FPCM.
- On average, grassland systems have higher emissions than mixed farming systems. Grassland systems contribute about 2.72 kg CO2-eq./kg FPCM, compared to mixed systems which on average contribute 1.78 kg CO2-eq./kg FPCM.
- Globally, cradle to farm gate emissions contribute, on average, 93 percent of total dairy GHG emissions.
- Methane contributes most to the global warming impact of milk – about 52 percent of the GHG emissions – from both developing and developed countries.
- Nitrous oxide emissions account for 27 and 38 percent of the GHG emissions in developed and developing countries, respectively, while CO2 emissions account for a higher share of emissions in developed countries (21 percent), compared to developing countries (10 percent).
- The amount of milk produced globally in 2007 was about 553 million tonnes.
- The total meat production related to the global dairy herd is estimated to be 34 million tonnes, or 57 percent of the total cattle meat production in the world and almost 13 percent of the total global meat production.
- The average greenhouse gas emissions from land use change are relatively low. The highest values are estimated for Western and Eastern Europe, where they account for 0.11 and 0.04 kg CO2-eq. per kg of FPCM at farm gate, respectively, representing 7 percent and 3 percent of the emissions per kg of FPCM at farm gate, respectively.
- Post-farm gate emissions range between 0.06 and 0.23 kg CO2-eq. per kg of FPCM at the farm gate.
- In comparing the total average life cycle emissions across different world regions, the highest emissions per kg of FPCM were found in developing regions with sub-Saharan Africa, South Asia, North Africa and the Near East with an average of 7.5, 4.6 and 3.7 kg CO2-eq. per kg of FPCM, respectively.
Other Important Findings
- The report identifies that the highest emissions per kg of FPCM were found in developing regions, particularly in sub-Saharan Africa, South Asia, North Africa, and the Near East, indicating that production in these areas is more emission-intensive than in industrialized regions.
- The study reveals a similar trend across all regions of the world, where on-farm activities, including land use change, contribute most significantly to overall GHG emissions.
- In the study, the average global emissions from milk production, processing, and transport is estimated to be 2.4 CO2-eq. per kg of FPCM at the farm gate.
- The research emphasizes the need for a system-wide assessment of GHG emissions of the dairy sector as a crucial first step in identifying potential mitigation opportunities.
- The study highlights that, along the entire dairy food chain, cradle-to-farm gate emissions contribute the highest proportion of emissions.
- Within the dairy herd, some animals only produce meat (fattened calves), others contribute to the combined production of meat and dairy products (milked cows, reproduction bulls and replacement stock). For the latter group, we chose to allocate GHG emissions on the basis of their protein content.
- The study also found that the emissions related to manure outside the livestock systems and to draught animals are separated from other dairy sector emissions. The remaining emissions are allocated to milk and meat on the basis of their proportional contribution to total protein production.
- Post-farm gate emissions vary by product, with fresh milk and cream having emissions of 0.153 kg CO2-eq./kg milk and whole milk powder and cream at 0.171 kg CO2-eq./kg milk.
- The average emission intensity is 1.36 kg CO2-eq. per kg milk, and the standard deviation is 0.163 kg.
Limitations Noted in the Document
- The study acknowledges that numerous hypotheses and methodological choices were made, introducing a degree of uncertainty in the results.
- The study relies on generalisations and projections due to a lack of comprehensive data, particularly for systems at lower levels of aggregation.
- Methodological choices and assumptions, such as system boundary delineation, functional units, and allocation techniques, may be subjective and affect the results.
- Post-farm gate emissions are related to a kg of milk equivalent at the farm-gate, rather than to each processed dairy product.
- The study excludes emissions related to land use under constant management practices, capital goods such as farm equipment and buildings, on-farm milking and cooling, and retail stage activities.
- The study uses IPCC standard emission factors at Tier 2 level, which may not permit direct comparisons with other studies that utilize country-specific emission factors.
Conclusion
The findings underscore the significant contribution of the global dairy sector to greenhouse gas emissions, particularly emphasizing the need for targeted mitigation strategies. The study identifies the major contributors to emissions, which include milk production, processing, transport, and meat production from dairy-related animals. This assessment reveals that the average global emissions from milk production, processing, and transport are estimated to be 2.4 CO2-eq. per kg of FPCM at the farm gate. Variations exist, with higher emissions in developing regions and grassland systems, highlighting the influence of farming practices and agro-ecological zones. Methane is the largest contributor to the total GHG emissions from the dairy sector, while nitrous oxide also plays a significant role. The analysis emphasizes the importance of a system-wide approach to understanding and mitigating emissions, with cradle-to-farm-gate emissions contributing the most. Furthermore, the study’s focus on protein content for allocating emissions reflects the sector’s primary role in providing edible protein, and identifies key parameters like digestibility, milk yield, and manure management as critical factors. The sensitivity and uncertainty analyses indicate that emission levels are sensitive to feed digestibility and yield values. The study notes that the methods and database developed for this assessment effectively supported the calculation of GHG emissions related to dairy production on a global scale, and may be considered an important step towards a harmonised methodology for the quantification of emissions. It is important to highlight the importance of assessing a broader range of environmental issues, including water resource degradation, biodiversity loss, erosion and other non-GHG impacts. The sustainability of the dairy sector needs to be understood within this broader context, and analysed considering the synergies and trade-offs among competing environmental, social and economic objectives. This study also notes that a global trend emerging from the results is the lower level of emissions per unit of product in intensive compared to extensive systems. Finally, the study highlights that the implementation of GHG mitigation measures requires not only technological development, but also economic incentives, and institutional frameworks that are adapted to the specific farm conditions and regions.