Context: According to a recent study by International Centre for Tropical Agriculture (CIAT), cow urine may also contribute to global warming.
- Livestock is used for meat, dairy products, eggs, fibre and leather, transport, and for manure to fertilize crops and for fuel.
- According to FAO 2006, the livestock sector accounts for 40 % of the world’s agriculture-related gross domestic product (GDP). It employs 1.3 billion people and provides livelihoods for around 1 billion of the world’s population living in poverty.
- However, it is also a major driver of climate change through the emissions of greenhouse gases such as carbon dioxide, CH4, and nitrous oxide.
Greenhouse Gas Emissions from Livestock: Facts and Figures
- Globally, the livestock sector contributes 14.5 % (7.1 billion tonnes CO2equivalent) of global anthropogenic greenhouse gas emissions. (FAO)
- Cattle is responsible for the most emissions, representing about 65% of the livestock sector’s emissions.
- In terms of activities, feed production and processing (45%) and enteric fermentation from ruminants (39%) are the two main sources of emissions
- About 44% of livestock emissions are in the form of methane (CH4). Nitrous Oxide accounts for 29% and Carbon Dioxide 27%
Sources of Greenhouse Gas Emission from Livestock:
- Methane (CH4) emissions from enteric fermentation:
- Ruminants such as cattle, sheep, buffalo, and goats produce methane, potent greenhouse gas that can contribute to global climate change, as part of their digestive process.
- Globally, ruminant livestock produce about 86 million metric tons of CH4 annually.
- Methane (CH4) and nitrous oxide (N2O) emissions from manure: Animal manure produces anthropogenic CH4 via anaerobic decomposition of manure and N2O via nitrification and denitrification of organic nitrogen in animal manure and urine.
- Carbon Emissions from feed production: Livestock operations require a variety of external inputs (i.e., feed production, herbicides, pesticides, etc.).
- Carbon dioxide emissions originate from the expansion of feed crops and pasture into natural habitats.
- They also originate from the use of fossil fuel to manufacture fertilizer, and process and transport feed.
- On-farm fossil fuel use:
- The livestock sector includes direct and indirect (e.g. electricity) on-farm fossil fuel use, which is used for machinery operations, irrigation, heating, cooling, ventilation etc.
- FAO, 2006 estimated that on-farm fossil fuel use emits 90 Tg CO2-eq. /year equivalent.
- Land-use change due to livestock:
- Land-use changes, including expansion of pasture and arable land for feed crops generally occur at the expense of forested land.
- FAO 2006, estimated that livestock-related land-use change produces 2,400 Tg CO2-eq. year−1 or 35 % of the total GHGs attributed to livestock.
- Post-Farm emissions: Post farm CO2 emissions is related to the processing and transportation of livestock product between the production and retail point.
- Land Degradation and Desertification:
- Overgrazing by livestock is one of the most important cause of land degradation and desertification. Such problem is prominent in Africa, Central Asia, north-eastern Australia, Pakistan, and Afghanistan.
- FAO, 2006 estimated that global emissions associated with livestock-induced desertification total 100 Tg CO2-eq.year−1.
- Improving Feed Quality and Digestibility: measures should be taken for better grassland management, improved pasture species, changing forage mix and greater use of feed supplements. These measures can improve nutrient uptake, increase animal productivity and fertility, and thus lower emissions per unit of product.
- Improving animal health and husbandry: There is a direct link between greenhouse gas emission intensities and animal efficiency- more productive the animal; lesser the environmental impact. Thus, it is important to improve animal health through measures such as animal health management, extending the productive life of animals, and improving reproduction rates to reduce the number of animals kept otherwise rather than production.
- Agroforestry: Agroforestry should be practiced to help maintain the balance between livestock production, environmental protection and carbon sequestration to offset emissions from the sector.
- Manure management: It is important to adopt sound manure management to mitigate GHG emissions, reduce nutrient losses from livestock production systems and reduce other detrimental environmental impacts of livestock production such as air and water pollution
- Grassland management: It is important to improve grazing and grassland management to increase feed quality and carbon sequestration. Further, overgrazing should be hauled to combat land degradation and desertification.
- Dietary Shifts: Shifting dietary trends in high income regions, -reduction in meat consumption and food waste would help negate the detrimental impacts of livestock farming to a large extent.
- Fiscal Measures: It is important to adopt fiscal measures such as polluter’s pay mechanism to control emissions from livestock farms. Further, fiscal incentives should be provide to facilitate adoption of mitigation/ adaptation strategies by farmers.
- Awareness: Raising awareness about impact of livestock/meat consumption on climate is important.
- Policy: Countries should develop sectorial mitigation policies that integrate other development objectives, and seek international support towards their implementation.