Abstract
Shorter lived climate forcers have been recognised as a means of moderating dangerous global warming over the next 20 years, allowing time for necessary longer term carbon dioxide abatement measures to take effect. Annual emissions of three short lived agents: methane, black carbon and tropospheric ozone combined have a greater warming impact than carbon dioxide emissions each year. Reducing these three forcers offers a powerful means of slowing potentially dangerous climate change. This paper examines how changing just one human activity-livestock production-can substantially cut shorter lived climate forcers as well as legacy carbon dioxide now in our atmosphere. Livestock production is shown to be the single largest source of methane, black carbon and tropospheric ozone (by methane’s effect on the production process). Livestock production also offers a substantial low cost means of reducing carbon dioxide emissions, since it is determined to be the largest driver of deforestation and the greatest cause of ‘open fires’ (burning of savannah lands and forests). Reducing livestock production is shown to draw down legacy carbon dioxide in natural, low cost processes of reforestation and building soil carbon. The climate impacts of this one industry offer a unique opportunity to stem global warming, giving the scientific and political communities time to work on longer term solutions.
Generated Summary
This journal article examines the impact of livestock production on climate change, particularly focusing on shorter-lived climate forcers (SLCFs) such as methane, black carbon, and tropospheric ozone. The study emphasizes that reducing these forcers offers a powerful means of slowing climate change in the short term, while also providing time for the implementation of longer-term carbon dioxide abatement measures. The research approach involves a review of existing literature, including reports from the UNEP & WMO and US EPA, and presents a case for reducing livestock production as a key strategy. The scope includes the examination of methane sources and the benefits of reducing livestock production, the impact of black carbon, ozone and deforestation on the environment, and the potential for reforestation and soil carbon sequestration. The main methodology used includes the synthesis of data and findings from existing research to support the authors’ arguments.
Key Findings & Statistics
- Global Warming Potential: Methane has a warming potential 72 times that of carbon dioxide over a 20-year time frame.
- Black Carbon Impact: Black carbon emissions are responsible for as much as 40% of the net global warming.
- Ozone Impact: Tropospheric ozone has a warming impact equal to about 20 percent of that of carbon dioxide.
- Methane Sources: At least a third of methane emissions come from livestock raising, a third from fugitive emissions from coal mining, gas, and oil refining, 10% from rice cultivation, about 17% from waste, and a smaller percentage from land use and forestry.
- Livestock’s Share of Warming: Over 20 years, warming from yearly methane emissions is almost equal to the warming from CO2 emitted each year.
- Livestock Consumption: Livestock consume 58% of global appropriated net primary production (NPP).
- Livestock vs. Wildlife: The weight of livestock exceeds wildlife by a factor of 8:1.
- Livestock and Megafauna: Consumption by livestock is now six times that of the megafauna at their peak.
- Land Use for Livestock: A quarter of the global land surface is used for livestock production.
- Grain for Livestock: Livestock are fed 45% of the world’s grain.
- Meat Consumption Increase: From 1950 to 2005, meat consumption rose from 47 million tonnes to 284 million tonnes, a six-fold increase.
- Deforestation Impact: Globally, human-caused fires emit 15% of global carbon dioxide emissions.
- Deforestation Rate: The average deforestation rate for the last decade was 13 million hectares each year, equivalent to an area of 360x360km.
- Deforestation Causes: Clearing for pasture and feed for livestock is responsible for between 60-80% of all clearing.
- Deforestation Emissions: Deforestation emits 2.9 gigatons of carbon annually, more than a quarter of all human caused emissions.
- Reforestation Potential: Reforestation could sequester 25 gigatons of carbon between 2000 and 2050.
- Soil Carbon Sequestration: Re-stocking of soil carbon can add as much as 50% to 66% of the historic soil carbon loss of 42 to 78 gigatons of carbon.
- Dietary Impact on Mitigation Costs: A low-meat diet would reduce climate change mitigation costs by about 50%. A no-meat diet would reduce mitigation costs by 70%, while an animal-free diet would reduce costs by 80%.
- Biodiversity Loss: A plant-based diet could reduce biodiversity loss by 60%.
Other Important Findings
- Methane Reduction: Reducing methane emissions, particularly from livestock production, is highlighted as a key strategy.
- Black Carbon Sources: The largest source of black carbon (42%) is from open fires, with 80–90% of these deliberately lit for pasture maintenance.
- Ozone Mitigation: The most effective means of controlling ozone is by reducing methane emissions from livestock production.
- Impact of Deforestation: Livestock production is the largest driver of deforestation, which contributes significantly to CO2 emissions and soil carbon loss.
- Reforestation as a Solution: Reforestation and soil carbon restocking are presented as low-cost methods for removing carbon dioxide from the atmosphere.
- Policy Recommendations: The article suggests policy imperatives like halting subsidies on livestock production, promoting plant-based alternatives, and protecting regrowth forests.
- Health Benefits: Reducing methane production is noted to provide significant health benefits.
Limitations Noted in the Document
- Focus on Shorter-Lived Forcers: The primary focus is on shorter-lived climate forcers, and while this is important, the document does not present a comprehensive view of all climate change mitigation strategies.
- Reliance on Existing Data: The study is based on a synthesis of existing research, which means the findings and conclusions are limited by the scope and quality of the original studies.
- Generalizations: Some generalizations are made about complex issues like livestock production and deforestation, which could be nuanced by regional variations.
- Limited Consideration of Alternatives: While the article advocates for plant-based diets, it does not provide a detailed analysis of the social and economic factors that could impact large-scale adoption.
- Oversimplification: The study might oversimplify complex issues like the role of grazing in land management.
Conclusion
The central argument underscores the profound impact of livestock production on climate change, emphasizing the urgent need for a shift towards more sustainable practices and dietary choices. The authors advocate for a reduction in livestock numbers as a key strategy to mitigate the effects of climate change, particularly concerning shorter-lived climate forcers like methane and black carbon. The research highlights the need to cut greenhouse gas emissions by reducing the reliance on animal agriculture and promote plant-based alternatives. This approach, the authors claim, could dramatically reduce climate change mitigation costs while also providing numerous health and environmental benefits. The authors emphasize the importance of addressing the role of livestock in climate change. The authors suggest that a substantial reduction in environmental impacts is only possible with a major shift away from animal products. This conclusion implies a fundamental change in the global approach to food systems and land use. It highlights the need to reconsider current agricultural practices and policies to promote a more sustainable approach. This includes rethinking current practices such as government subsidies that support livestock production, and instead, support practices that promote sustainable options. The authors propose policy imperatives such as halting subsidies on livestock production and promoting plant-based alternatives, which, if adopted, could substantially reduce climate change mitigation costs, protect and restore regrowth forests in grazing lands and reduce anthropogenic open burning, and fund alternative land uses such as tree carbon sequestration and organic farming. The final takeaway is clear: a decisive shift away from animal products is essential to effectively combat climate change and secure a sustainable future.
IFFS Team Summary
- Excellent review of the extent that land use change from animal agriculture impacts GHG and global warming
- CO2, Methane, Nitrous Oxide, Black Carbon and short lived gasses are reviewed
- The mechanism, sources and promotional attribution to livestock is quantified
- Land use change includes deforestation and other land clearance for pasture or crops which feed animals
- 33% of anthropogenic methane emission is due to livestock
- Ruminants, biomass decomposition from land clearance, and animal waste are the three causes
- 80-90% of global forest and environmental fires are deliberately
- These are for burning crop residue, or land clearance for grazing / animal feed
- CO2 and black carbon are emitted
- The weight of livestock outweigh all other wild animal biomass by 8:1
- Weigh 6:1 all megafauna biomass at at their peak
- Consume 45% of the world’s grain
- Use up at last 25% of the earth’s non frozen surface
- But provide only 17% of the world’s calories
- The world’s total meat consumption in 1950 was 47 million tonnes
- By 2006 it 284 millions tonnes
- This is a 6 x increase, despite only a doubling in world population
- GHG emissions vary from various sources
- And emissions estimates may vary due to factors included, excluded, or given different weights by authors
- Animal respiration, as per world watch report, is still worthy to consider
- 60-80% of ongoing global deforestation is attributable to animal agriculture
- Slash and burn for subsistence agriculture is decreasing globally as populations become more urban
- Most deforestation is not done by large scale industry, especially for animal agriculture
- Reforestation is the best and most most effective way to store carbon
- Above ground in the form of trees
- Below ground in soil, as soil carbon and tubers,roots and plant biomass
- Low meat, no meat, and animal product free diets offer progress carbon reduction and sequestration potential
- this could sharply decrease global deforestation, open fires, and allow 70% of global agricultural land for reforestation
- Soil loss, desertification, and water consumption would also decrease sharply
- Subsidies for the meat industry should be eliminated, which greatly exacerbates animal agriculture