REFERENCES: EFFECTS OF INDUSTRIAL ANIMAL AGRICULTURE ON ENV’T/ HUMAN HEALTH

Be sure to look at other sections in this area on sustainable diets as there is likely to be crossover.  Below are also papers focused on the impact of industrial animal agriculture on the environment and climate and the benefits of plant based diets for health and planet. Please note that there is evidence that animal protein may be necessary and essential  in certain regions of the world and that animal agriculture done in a way that is ecologically friendly and humane can be important culturally, economically, and health-wise.  If you are looking for a place to start, check out the papers marked with *** which indicates papers that are recent and, in my opinion, very well laid out.

• Barré T, Perignon M, Gazan R, et al. Integrating nutrient bioavailability and co-production links when identifying sustainable diets: How low should we reduce meat consumption? PLOS ONE. 2018;13(2).
  • Reducing the consumption of meat and other animal-based products is widely advocated to improve the sustainability of diets in high-income countries. However, such reduction may impair nutritional adequacy, since the bioavailability of key nutrients is higher when they come from animal- vs plant-based foods.
• Burkholder, J., Libra, B., Weyer, P., Heathcote, S., & al, e. Impacts of waste from concentrated animal feeding operations on water quality. Environmental Health Perspectives, 115(2), 308-12. (2007)
  • Based on available data, generally accepted livestock waste management practices do not adequately or effectively protect water resources from contamination with excessive nutrients, microbial pathogens, and pharmaceuticals present in the waste. Impacts on surface water sources and wildlife have been documented in many agricultural areas in the United States. 
  • The recent growth of concentrated animal feeding operations (CAFOs) presents a greater risk to water quality because of both the increased volume of waste and to contaminants that may be present (e.g., antibiotics and other veterinary drugs) that may have both environmental and public health importance.

• Chai BC, van der Voort JR, Grofelnik K, Eliasdottir HG, Klöss I, Perez-Cueto FJA. Which diet has the least environmental impact on our planet? A Systematic review of vegan, vegetarian and omnivorous diets. Sustainability. 2019; 11(15):4110.

  • Life Cycle Impact Assessment technique (LCAs) [8]. LCAs can estimate the environmental impacts of production, transport, processing, storage, waste disposal and other life stages of food production 
  • Using natural resources (land, water and fossil energy) to raise livestock and produce crops increases environmental degradation day by day.
  • Results from our review suggest that the vegan diet is the optimal diet for the environment because, out of all the compared diets, its production results in the lowest level of GHG emissions.
  • Additionally, the reviewed studies indicate the possibility of achieving the same environmental impact as that of the vegan diet, without excluding the meat and dairy food groups, but rather, by reducing them substantially.

• Center for a Livable Future Report. Johns Hopkins University.  The Importance of Reducing Animal Product Consumption and Wasted Food in Mitigating Catastrophic Climate Change. COP 21. 2015

  • If global trends in meat and dairy intake continue, global mean temperature rise will more than likely exceed 2° C, even with dramatic emissions reductions across non‐agricultural sectors.
  • Immediate and substantial reductions in wasted food and meat and dairy intake, particularly ruminant meat (e.g., beef and lamb), are imperative to mitigating catastrophic climate change.
• Clark et al.  SUMMARY PAPER 2: The role of healthy diets in creating environmentally sustainable food systems World Health Organization/FAO ”SUSTAINABLE HEALTHY DIETS GUIDING PRINCIPLES” (2019)
  • “Global adoption of a low-meat diet that meets nutritional recommendations for fruits, vegetables, and caloric requirements is estimated to reduce diet-related GHGs by nearly 50 percent, and premature mortality by nearly 20 percent. “
  • “In addition to dietary changes, other changes to the food system could further reduce its environmental impact, including reductions in food loss and waste; technology implementation and changes in management to improve crop yields and reduce fertilizer and pesticide runoff; and changes in food formulation, processing, and preparation.”
  • “The benefits of adopting environmentally sustainable and healthy diets will vary by country”
• Craig WJ, Mangels AR, Fresán U, Marsh K, Miles FL, Saunders AV, Haddad EH, Heskey CE, Johnston P, Larson-Meyer E, Orlich M. The Safe and Effective Use of Plant-Based Diets with Guidelines for Health Professionals. Nutrients. 2021 Nov 19;13(11):4144.
  • An increasing body of data provides evidence that environmental degradation, through the emissions of greenhouse gas (GHG) and other pollutants, and the use of earth’s resources, such as water and land, in the production of plant-based foods are significantly lower than that from animal-based foods
  • The production of plant-based products is more efficient regardless of whether the comparison is made by weight of product, per serving, per calories, or even protein content
  • Producing the same amount of protein from tofu (soybeans) in comparison to beef protein requires 74 times less land and eight times less water, while the GHG emissions are 25 times lower and the eutrophication (a process driven by the enrichment of water by nutrients, especially compounds of nitrogen and/or phosphorus, leading to an increased growth, primary production and biomass of algae; changes in the balance of organisms; and water quality degradation

• Eisen MB, Brown PO. Rapid global phaseout of animal agriculture has the potential to stabilize greenhouse gas levels for 30 years and offset 68 percent of CO2 emissions.

  • Animal agriculture contributes significantly to global warming through ongoing emissions of the potent greenhouse gases methane and nitrous oxide, and displacement of biomass carbon on the land used to support livestock.
  • Even in the absence of any other emission reductions, persistent drops in atmospheric methane and nitrous oxide levels, and slower carbon dioxide accumulation, following a phase out of livestock production would, through the end of the century, have the same cumulative effect on the warming potential of the atmosphere as a 25 gigaton per year reduction in anthropogenic CO2 emissions, providing half of the net emission reductions necessary to limit warming to 2°C.
• FAO. 2020. Livestock and environment statistics: manure and greenhouse gas emissions. Global, regional and country trends, 1990–2018. FAOSTAT Analytical Brief Series No. 14. Rome.
  • Two-thirds of agricultural emissions come from grazing livestock, with cattle responsible for the largest contribution
• Farvid, M. S., Sidahmed, E., Spence, N. D., Mante Angua, K., Rosner, B. A., & Barnett, J. B. (2021). Consumption of red meat and processed meat and cancer incidence: a systematic review and meta-analysis of prospective studies .European Journal of Epidemiology, 36(9), 937–951. https://doi.org/10.1007/S10654-021-00741-9
  • This comprehensive systematic review and meta-analysis study showed that high red meat intake was positively associated with risk of breast cancer, endometrial cancer, colorectal cancer, colon cancer, rectal cancer, lung cancer, and hepatocellular carcinoma, and high processed meat intake was positively associated with risk of breast, colorectal, colon, rectal, and lung cancers. Higher risk of colorectal, colon, rectal, lung, and renal cell cancers were also observed with high total red and processed meat consumption.
• Fry JP, Stodden B, Brace AM, Laestadius LI. A Tale of Two Urgent Food System Challenges: Comparative Analysis of Approaches to Reduce High-Meat Diets and Wasted Food as Covered in U.S. Newspapers. Sustainability. 2022; 14(19):12083.
  • “There is clear scientific evidence that diets in high-income countries need to shift away from animal-based foods and towards plant-based foods not only to reduce GHGs (greenhouse gases) to address climate change but also to reduce resource use (e.g., land, water) and pollution,” write the scientists from Maryland’s Towson University and the University of Wisconsin, “but many newspaper journalists are presenting ‘both sides’ and, therefore, covering the issue as an open debate.”
  • Forbes Article that covers the study in more plain language:  Journalists Are Making The Same Mistake With Dietary Change They Made With Climate Change: Study

• Gardner CD, Hartle JC, Garrett RD, Offringa LC, Wasserman AS. Maximizing the intersection of human health and the health of the environment with regard to the amount and type of protein produced and consumed in the United States. Nutrition Reviews. 2019;77(4):197-215.

• Gerber PJ, Steinfeld H, Henderson B, et al. Tackling climate change through livestock – A global assessment of emissions and mitigation opportunities. Food and Agriculture Organization of the United Nations (FAO), Rome; 2013.

• Gibbs J, Cappuccio FP. Plant-Based Dietary Patterns for Human and Planetary Health. Nutrients. 2022;14(8):1614. Published 2022 Apr 13. doi:10.3390/nu14081614 ***
  • Current agricultural practices constitute up to 30% of global anthropogenic GHG emissions [6] and 70% of freshwater use [7], whilst occupying approximately 40% of Earth’s land [8]. Therefore, innovation within the agricultural sector has the potential to generate substantial sustainability gains.
  • Reducing red meat consumption is a major key to meeting emission targets for very high HDI countries and it would deliver substantial health co-benefits. The rate of red meat-related mortality is nearly nine times greater in very high HDI countries than in low HDI countries
  • It is time for developed nations to commit to red meat reduction targets and shift to plant-based dietary patterns. Transitioning to plant-based diets (PBDs) has the potential to reduce diet-related land use by 76%, diet-related greenhouse gas emissions by 49%, eutrophication by 49%, and green and blue water use by 21% and 14%, respectively, whilst garnering substantial health co-benefits. An extensive body of data from prospective cohort studies and controlled trials supports the implementation of PBDs for obesity and chronic disease prevention.
  • Plant-based foods have a significantly smaller footprint on the environment than animal-based foods. Even the least sustainable vegetables and cereals cause less environmental harm than the lowest impact meat and dairy products.
  • Considering the amount of land required to produce animal products, it is unsurprising that they are accountable for 67% of the deforestation caused by agriculture [9]. The destruction of ecosystems for croplands and pasturelands is the single largest factor causing species to be threatened with extinction [18]. Biodiversity is essential for the productivity and resilience of our food systems [19]. Shifting to PBDs would slow biodiversity loss substantially, thus having a protective effect on global food security.
• Godfray HCJ, Aveyard P, Garnett T, Hall JW, Key TJ, Lorimer J, Pierrehumbert RT, Scarborough P, Springmann M, Jebb SA. Meat consumption, health, and the environment. Science. 2018 Jul 20;361(6399):eaam5324
  • “The consumption of different types of meat and meat products has substantial effects on people’s health, and livestock production can have major negative effects on the environment.”
  • Although meat is a concentrated source of nutrients for low-income families, it also enhances the risks of chronic ill health, such as from colorectal cancer and cardiovascular disease.
  • “Meat production is the single most important source of methane, which has a relatively high warming potential but a low half-life in the environment compared with that of CO2. Careful management of grassland systems can contribute to carbon storage, but the net benefits are likely to be relatively modest. Agriculture uses more freshwater than any other human activity, with nearly a third required for livestock, so meat production in water-stressed areas is a major competitor with other uses of water, including that required to maintain natural ecosystems. Meat production can be an important source of nitrogen, phosphorus, and other pollutants and affects biodiversity—in particular, through land conversion to pasture and arable feed crops.”
•  Guglielmi, G. Eating one-fifth less beef could halve deforestation. Nature. May 4th 2022. Accessed October 2022
  •  Swapping 50% of the beef consumed per person for mycoprotein would result in a more than 80% reduction in deforestation and carbon emissions, and replacing 80% of beef with mycoprotein would eliminate about 90% of forest loss.
• Hall J, Galarraga J, Berman I, Edwards C, Khanjar N, Kavi L, Murray R, Burwell-Naney K, Jiang C, Wilson S. Environmental Injustice and Industrial Chicken Farming in Maryland. Int J Environ Res Public Health. 2021 Oct 20;18(21):11039. doi: 10.3390/ijerph182111039.
  • The number of animals raised at industrial production facilities increased by nearly 246% between 1982 and 2002 while the total number of livestock raised in the year 2000 was equal to that of the previous 80 years
  • Due to the concentration of animals and the density of industrial farms, these operations pose threats to environmental and human health. For example, thousands of pounds of harmful emissions including volatile organic compounds (VOCs), ammonia, nitrogen, carbon dioxide, methane, particulate matter (PM), and heavy metals are emitted from CAFOs on an annual basis
  • The distribution of CAFOs and meat processing plants across Maryland may contribute to poor health outcomes in areas affected by such production, and contribute to health disparities and health inequity.
• Hayek, Matthew N., and Rachael D. Garrett. “Nationwide shift to grass-fed beef requires larger cattle population.” Environmental Research Letters 13, no. 8 (2018): 084005.
  •  If the entire U.S. beef supply were converted to grass-fed production, existing pasture land could only support 27% of current demand and, due to the necessary increased herd size, total U.S. methane emissions would rise by 8%.
• Humpenöder, F., Bodirsky, B.L., Weindl, I. et al. Projected environmental benefits of replacing beef with microbial protein. Nature 605, 90–96 (2022).
  • Life cycle assessment (LCA) studies have estimated substantial environmental benefits of MP, produced in bioreactors using sugar as feedstock, especially compared to ruminant meat
• IPCC. 2019. Summary for Policymakers. In: Climate Change and Land: an IPCC special report on climate change, desertification, land degradation, sustainable land management, food security, and greenhouse gas fluxes in terrestrial ecosystems. [P.R. Shukla, J. Skea, E. Calvo Buendia, V. Masson-Delmotte, H.- O. Pörtner, D. C. Roberts, P. Zhai, R. Slade, S. Connors, R. van Diemen, M. Ferrat, E. Haughey, S. Luz, S. Neogi, M. Pathak, J. Petzold, J. Portugal Pereira, P. Vyas, E. Huntley, K. Kissick, M. Belkacemi, J. Malley, (eds.)].
  • Discusses the urgency of addressing greenhouse gas emissions from food and agriculture in order to meet climate goals.
• Ivanovich, C.C., Sun, T., Gordon, D.R. et al. Future warming from global food consumption. Nat. Clim. Chang. (2023) ***.
  • We find that global food consumption alone could add nearly 1 °C to warming by 2100. Seventy five percent of this warming is driven by foods that are high sources of methane (ruminant meat, dairy and rice). 
  • Emissions from food alone, ignoring the huge impact of fossil fuels, would push the world past the 1.5C limit.
  • Current dietary production and consumption patterns are incompatible with sustaining a growing population while pursuing a secure climate future.
  • Temperature rise could be cut by 55% by cutting meat consumption in rich countries to medically recommended levels.
  • Consumer Friendly Article detailing this report from The Guardian: Meat, dairy and rice production will bust 1.5C climate target, shows study
• Katz, David. Plant-Based Diets for Reversing Disease and Saving the Planet: Past, Present, and Future, Advances in Nutrition, Volume 10, Issue Supplement_4, November 2019, Pages S304–S307
  • The evidence is strong, consistent, and compelling that a diet of predominantly, or even exclusively, whole plant foods can promote health, selectively treat and reverse disease, and confer comparable benefit to the planet.

• Kevany S. 20 meat and dairy firms emit more greenhouse gas than Germany, Britain or France. The Guardian. Published September 7, 2021.

• Kim, B et al.  The Importance of Reducing Animal Product Consumption and Wasted Food in Mitigating Catastrophic Climate Change.  Johns Hopkins Center for a Livable Future.  Dec 2015.

  • Immediate and substantial reductions in wasted food and meat and dairy intake, particularly ruminant meat (e.g., beef and lamb), are imperative to mitigating catastrophic climate change

• Klapp, Anna, Nico Feil, Antje Risius, A Global Analysis of National Dietary Guidelines on Plant-Based Diets and Substitutions for Animal-Based Foods, Current Developments in Nutrition, Volume 6, Issue 11, November 2022, nzac144, ***
  • “In conclusion, with global planetary and human health goals and targets falling short, it is more important than ever to ensure that FBDGs promote sustainable healthy food choices. This includes recommendations to eat fewer animal products and fostering plant-based diets and plant-based alternatives as part of their positions and food groups. Policy makers, civil society actors, and economic agents have to use all available tools to promote more sustainable, healthy, and equitable consumption patterns. FBDGs that encourage balanced food choices are also more inclusive in that they consider ethical, ecological, religious, and economic aspects that play roles in people’s everyday lives.”
• Rieger, J Et al. From fork to farm: Impacts of more sustainable diets in the EU-27 on the agricultural sector. Journal of Agricultural Economics. 11 February 2023 https://doi.org/10.1111/1477-9552.12530
  • Globally, approximately 43 kg of meat and 88 kg of milk are consumed per capita per year. In Europe, these figures are twice as high, with 78 kg of meat and 216 kg of milk per capita per year. As a result, Europeans consume an average of almost 800 kcal per day from animal-based foods (FAO, 2020), which is well above nutritional recommendations (DGE, 2017) and an estimated healthy and sustainable amount of 300 kcal per day (Willett et al., 2019).
  • Although supply-side measures such as technological and management advances to improve agricultural yields, fertiliser efficiency, manure management or feed conversion rates of animals are important, they will not be sufficient to stay within planetary boundaries and reduce agricultural GHG emissions to the level required to meet the 2°C target
• Loken B, DeClerck F. Eat Forum. Diets for a better future: Rebooting and reimagining healthy and sustainable food systems in the G20. 
• Loken, B.  Nature-based Solutions can save the planet, but only if we change our diets too World Economic Forum Website.  2021
  
• Lovegrove, J.A., O’Sullivan, D.M., Tosi, P., Millan, E., Todman, L.C., Bishop, J. et al. (2023) ‘Raising the Pulse’: The environmental, nutritional and health benefits of pulse-enhanced foods  Nutrition Bulletin, 00, 1– 10.
  • When compared with other nutrient-dense foods like quinoa, pulse production has greater inherent sustainability due to the ability of pulses, in cooperation with symbiotic rhizobia bacteria, to biologically fix nitrogen from the atmosphere (rather than relying on fertilisation with ar-tificial nitrogen fertilisers synthesised with high-carbon footprint) to form edible protein.
  • Amongst grain legumes, faba bean has the highest yield potential (Cernay et al., 2016) and nitrogen-fixation rates (Baddeley et al., 2013) in the United Kingdom and globally, while providing valuable floral resources for a diversity of wild pollinating insects (Bailes et al., 2018). As it can be sown as a winter or spring crop and can be harvested for a long period fol-lowing maturation, it is also the most flexible pulse for a diversity of farming systems and end uses.
• Manyi-Loh, C., Mamphweli, S., Meyer, E., Okoh, A. (2018). Antibiotic use in agriculture and its consequential resistance in environmental sources: potential public health implications. Molecules, 23(4), 795.
•  Mathur, M et al. Interventions to reduce meat consumption by appealing to animal welfare: Meta-analysis and evidence-based recommendations. Appetite Volume 164, 1 September 2021, 105277
  • Excessive consumption of meat and animal products may be deleterious to human health (with meta-analytic evidence regarding cancer (Crippa et al., 2018; Farvid et al., 2018; Gnagnarella et al., 2018; Larsson & Wolk, 2006), cardiovascular disease (Cui et al., 2019; Guasch-Ferré et al., 2019; Zhang and Zhang, 2018), metabolic disease (Fretts et al., 2015; Kim & Je, 2018; Pan et al., 2011), obesity (Rouhani et al., 2014), stroke (Kim et al., 2017), and all-cause mortality (Larsson & Orsini, 2013; Wang et al., 2016)); promotes the emergence and spread of pandemics and antibiotic-resistant pathogens (Bartlett et al., 2013; Di Marco et al., 2020; Marshall & Levy, 2011); is a major source of greenhouse gas emissions, environmental degradation, and biodiversity loss (Machovina et al., 2015; Sakadevan & Nguyen, 2017); and contributes to the preventable suffering and slaughter of approximately 500 to 12,000 animals over the lifetime of each human consuming a diet typical of his or her country

• Poore J, Nemecek T. Reducing Food’s environmental impacts through producers and consumers. Science. 2018;360(6392):987-992. 

  • Livestock production has many negative environmental impacts, especially in terms of deforestation, greenhouse gas emissions, water use and eutrophication
• Project Drawdown. 2020. “Table of Solutions.” February 5, 2020. https://www.drawdown.org/solutions/table-of-solutions
  • Shifting toward plant-rich diets is the third most impactful climate solution, with the potential to reduce more emissions than practices like improved manure management, improved cattle feed, managed grazing, and silvopasture can achieve combined.

• Provenza FD, Kronberg SL, Gregorini P. Is Grassfed Meat and Dairy Better for Human and Environmental Health?. Front Nutr. 2019;6:26. Published 2019 Mar 19.

• Putting Meat on the Table: Industrial Farm Animal Production: A Report of the Pew Commission on Industrial Farm Animal Production

• Raising animals in an industrial system. FoodPrint. Published December 10, 2020.

• Ranganathan J, Waite R. Sustainable diets: What you need to know in 12 charts. World Resources Institute. Published April 20, 2016.

  • It shows that just small shifts in the choices consumers make can have a huge impact in reducing agriculture’s resource use and mitigating environmental problems—the average American, for example, could cut their diet’s environmental footprint in half just by eating less meat and dairy.
  • Global average per person protein consumption exceeded dietary requirements in all regions in 2009, with each person consuming on average about 68 grams per day— one-third higher than the average daily adult requirement. 
  • Beef production requires 20 times more land and emits 20 times more greenhouse gas emissions per unit of edible protein than common plant-based protein sources such as beans, peas and lentils. Chicken and pork are more resource-efficient than beef, but still require three times more land and emit three times more greenhouse gas emissions than beans. 

• Ranganathan J, Waite R. Animal-based Foods are More Resource-Intensive than Plant-Based Foods  – World Resources Institute Published April 20, 2016.

• Ritchie, H.  Land Use Diets.  Our World in Data Website. https://ourworldindata.org/land-use-diets  Published March 04, 2021.  Accessed June 2023
  • Research suggests that if everyone shifted to a plant-based diet we would reduce global land use for agriculture by 75%. This large reduction of agricultural land use would be possible thanks to a reduction in land used for grazing and a smaller need for land to grow crops. The research also shows that cutting out beef and dairy (by substituting chicken, eggs, fish or plant-based food) has a much larger impact than eliminating chicken or fish
  • Of course the type of land used to raise cows or sheep is not the same as cropland for cereals, potatoes or beans. Livestock can be raised on pasture grasslands, or on steep hills where it is not possible to grow crops. Two-thirds of pastures are unsuitable for growing crops.² This raises the question of whether we could, or should, stop using it for agriculture at all. We could let natural vegetation and ecosystems return to these lands, with large benefits for biodiversity and carbon sequestration.
  • Less than half of the world’s cereals are fed directly to humans
  • Great graphics here

• Rust NA, Ridding L, Ward C, et al. How to transition to reduced-meat diets that benefit people and the planet. Sci Total Environ. 2020;718:137208.

  • “Overwhelming evidence shows that overconsumption of meat is bad for human and environmental health and that moving towards a more plant-based diet is more sustainable. For instance, replacing beef with beans in the US could free up 42% of US cropland and reduce greenhouse gas emissions by 334 mmt, accomplishing 75% of the 2020 carbon reduction target.”
• Sabaté J, Soret S. Sustainability of plant-based diets: back to the future. Am J Clin Nutr. 2014; 100 Suppl 1:476S-482S.
  • “Going back” to plant-based diets worldwide seems to be a reasonable alternative for a sustainable future. Policies in favor of the global adoption of plant-based diets will simultaneously optimize the food supply, health, environmental, and social justice outcomes for the world’s population. Implementing such nutrition policy is perhaps one of the most rational and moral paths for a sustainable future of the human race and other living creatures of the biosphere that we share.
• Sakadevan, K., & Nguyen, M.-L. (2016, December 7). Livestock production and its impact on nutrient pollution and greenhouse gas emissions. Advances in Agronomy.
  • “The intensification of livestock production led to large surpluses of on-farm nitrogen and phosphorus inputs that can potentially contribute to nonpoint source pollution of water resources in many parts of the world.”
• Scarborough, P., Clark, M., Cobiac, L. et al. Vegans, vegetarians, fish-eaters and meat-eaters in the UK show discrepant environmental impacts. Nat Food 4, 565–574 (2023). https://doi.org/10.1038/s43016-023-00795-w ***
  • There is a strong relationship between the amount of animal-based foods in a diet and its environmental impact, including GHG emissions, land use, water use, eutrophication & biodiversity. Any reduction in animal foods in the diet has a significant beneficial impact on all aspects of planetary health examined. Lower meat diets (<50g/day) have half the CO2 impact of high meat diets & vegan diets have half the impact of lower meat diets. 
  • We link dietary data from a sample of 55,504 vegans, vegetarians, fish-eaters and meat-eaters with food-level data on greenhouse gas emissions, land use, water use, eutrophication risk and potential biodiversity loss from a review of 570 life-cycle assessments covering more than 38,000 farms in 119 countries.
  • Despite substantial variation due to where and how food is produced, the relationship between environmental impact and animal-based food consumption is clear and should prompt the reduction of the latter.
  • The UK has a legal commitment to a 78% reduction in GHG emissions by 2035 compared to 1990¹⁷ and of halting biodiversity loss by 2030¹⁸. Our results suggest that much bigger reductions can be achieved by increasing the uptake of plant-based diets, which aligns with other results from this field^7,8,11.

• Semba, Kim, et al. Major Health Gains and Carbon Savings Possible from a Shift to Plant-based Diets. Nature Food. 2020

  • “Overall the adoption of a healthy, plant-based diet around the world would significantly reduce greenhouse gas emissions, and improve health,” says senior author of the study, Richard Semba, MD, MPH, the W. Richard Green Professor of Ophthalmology at the Johns Hopkins School of Medicine and an associated faculty member with CLF. “However, in some poor countries where people’s diets are really lacking in vital nutrients, achieving a healthy diet would actually lead to an increase in carbon emissions unless additional action were taken to mitigate against this.”
• Shah UA, Merlo G. Personal and Planetary Health—The Connection With Dietary Choices. JAMA.2023;329(21):1823–1824. doi:10.1001/jama.2023.6118
  • The world now produces more than 3 times the meat and more than double the milk as it did 50 years ago. This has well-established negative effects on the environment, including the destruction of native ecosystems to support livestock grazing and increased cultivation of animal feedstocks. Livestock and its supply chain also contribute to greenhouse gas emissions, such as carbon dioxide, methane, and nitrous oxide. Livestock farming accounts for 50% of methane and 60% of nitrous oxide emissions, which respectively have 25 and 298 times the global warming potential of carbon dioxide on a mass basis.
  • Additionally, most nitrogen pollution in wastewater is due to animal-based protein sources and inefficient agricultural practices, which lead to acid rain and toxic algal blooms that cause dead zones of aquatic life.
  • “Our dietary choices have broad and far-reaching impacts. It is no longer just about human health but planetary health as well. Advocating for a reduction in our consumption of animal foods needs to become a central part of climate change education, discussion, and solution. Switching to a plant-based diet is likely one of the fastest and easiest paths to turning the ship.  (Comment from Sharon Mcdowell-Larsen, PhD | Center for Creative Leadership)
• Son, J., Miranda, M. L., & Bell, M. L. (2021). Exposure to concentrated animal feeding operations (CAFOs) and risk of mortality in North Carolina, USA. Science of the Total Environment, 799(149407). 

• Sun, Z., Scherer, L., Tukker, A. et al. Dietary change in high-income nations alone can lead to substantial double climate dividend. Nat Food 3, 29–37 (2022).

  • A dietary shift from animal-based foods to plant-based foods in high-income nations could reduce greenhouse gas emissions from direct agricultural production and increase carbon sequestration if resulting spared land was restored to its antecedent natural vegetation
  •  Dietary change could reduce annual agricultural production emissions of high-income nations’ diets by 61% while sequestering as much as 98.3 (55.6–143.7) GtCO₂ equivalent, equal to approximately 14 years of current global agricultural emissions until natural vegetation matures.
• Sun, Z., Scherer, L., Zhang, Q. et al. Adoption of plant-based diets across Europe can improve food resilience against the Russia–Ukraine conflict. Nat Food 3, 905–910 (2022).
  • A transition towards the EAT-Lancet’s planetary health diet in the European Union and the United Kingdom alone would almost compensate for all production deficits from Russia and Ukraine while yielding improvements in blue water use, greenhouse gas emissions  and carbon sequestration
• Sustainable Agriculture: Beef. World Wildlife Fund.  Website.  https://www.worldwildlife.org/industries/beef. Accessed Sept 2022
  • “Beef production has a considerable effect on climate change due to emissions of greenhouse gases such as methane, nitrous oxide and carbon dioxide. Research shows that ruminant livestock account for between 7% and 18% of global methane emissions from human-related activities.”
• Twine, R. Emissions from Animal Agriculture—16.5% Is the New Minimum Figure Sustainability 2021, 13(11), 6276;  Published: 2 June 2021
  •  Subsequent work such as the EAT-Lancet commission [7] calls for substantial reductions in meat consumption within a co-benefit framing of improving human health and achieving emissions reductions (as well as other concerns including biodiversity and water conservation). The commission argued that transitioning to more sustainable diets is necessary to successfully meet the mitigation targets of the Paris Agreement and the United Nations’ Sustainable Development Goals (SDGs)
• Tzeng HT, Chyuan IT, Chen WY. Shaping of Innate Immune Response by Fatty Acid Metabolite Palmitate. Cells. 2019;8(12):1633
  • Corn fed beef is higher in palmitic acid which is associated with inflammation and obesity
• United Nations Environment Programme and Climate and Clean Air Coalition. 2021. Global Methane Assessment: Benefits and Costs of Mitigating Methane Emissions. Nairobi: United Nations Environment Programme.
  • Executive Report: https://wedocs.unep.org/bitstream/handle/20.500.11822/35917/GMA_ES.pdf 
  • “Globally…In the agricultural sector, livestock emissions from manure and enteric fermentation represent roughly 32 per cent, and rice cultivation 8 per cent of global anthropogenic emissions”
• The White House. 2021. The White House Office of Domestic Climate Policy, U.S. Methane Emissions Reduction Action Plan 6.   (citing EPA, Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2019 (2021)).
  • Animal agriculture is the largest source of methane in the U.S., driven by enteric fermentation from cattle.
• Willet, W et al. Food in the Anthropocene: the EAT–Lancet Commission on healthy diets from sustainable food systems  THE LANCET COMMISSIONS| VOLUME 393, ISSUE 10170, P447-492, FEBRUARY 02, 2019
  • Food systems have the potential to nurture human health and support environmental sustainability; however, they are currently threatening both. Providing a growing global population with healthy diets from sustainable food systems is an immediate challenge. 
  • Because much of the world’s population is inadequately nourished and many environmental systems and processes are pushed beyond safe boundaries by food production, a global transformation of the food system is urgently needed.
• Willet, W. Food Planet, Health.  Healthy Diets From Sustainable Food Systems.  E.A.T. EAT-Lancet Commission Summary Report, 2019
  • Food is the single strongest lever to optimize human health and  environmental sustainability on Earth.
  • A radical transformation of the global food system is urgently needed. Without action, the world risks failing to meet the UN Sustainable Development Goals (SDGs) and the Paris Agreement, and today’s children will inherit a planet that has been severely degraded and where much of the population will increasingly suffer from malnutrition and preventable disease.
  • A diet rich in plant-based foods and with fewer animal source foods confers both improved health and environmental benefits.
  • Operating outside this space for any Earth system process (e.g. high rates of biodiversity loss) or food group (e.g. insufficient vegetable intake) increases the risk of harm to the stability of the Earth system and human health.
  • This includes a more than doubling in the consumption of healthy foods such as fruits, vegetables, legumes and nuts, and a greater than 50% reduction in global consumption of less healthy foods such as added sugars and red meat (i.e. primarily by reducing excessive consumption in wealthier countries). However, some populations worldwide depend on agropastoral livelihoods and animal protein from livestock
• Wolf, J., Asrar, G.R. & West, T.O. Revised methane emissions factors and spatially distributed annual carbon fluxes for global livestock. Carbon Balance Manage 12, 16 (2017). https://doi.org/10.1186/s13021-017-0084-y
  • In this study, we update information for cattle and swine by region, based on reported recent changes in animal body mass, feed quality and quantity, milk productivity, and management of animals and manure. We then use this updated information to calculate new livestock methane emissions factors for enteric fermentation in cattle, and for manure management in cattle and swine.
  • Our results suggest that livestock methane emissions, while not the dominant overall source of global methane emissions, may be a major contributor to the observed annual emissions increases over the 2000s to 2010s.
• Xu, X., Sharma, P., Shu, S. et al. Global greenhouse gas emissions from animal-based foods are twice those of plant-based foods. Nat Food 2, 724–732 (2021).
  • “More than half of those emissions (from  the food system’s global greenhouse-gas emission) are driven by livestock farming (57%)
  • We define animal-based food emissions as the emissions from all subsectors caused by or associated with the production and consumption of animal-based food (Methods and Table 1). I
  • We include LUC  (Land use change) emissions from the expansion of agricultural land (crop plus grazing land) and from beyond farm-gate emissions under the life-cycle assessment (LCA) framework of Poore and Nemecek5 to include emissions from fertilizers, pesticides and pre-plate product processing and transportation.
  • Consumer-friendly article from Scientific American: Thompson A. Here’s how much food contributes to climate change: Animal-based foods produce about twice the emissions of plant-based ones, a new comprehensive study finds.  September 2021.

OPTIONS FOR REPLACING ANIMAL-BASED FOODS WITH PLANT-BASED MEATS

• Humpenöder, F., Bodirsky, B.L., Weindl, I. et al. Projected environmental benefits of replacing beef with microbial protein. Nature 605, 90–96 (2022).
  • Our model projections show that substituting 20% of per-capita ruminant meat consumption with MP globally by 2050 (on a protein basis) offsets future increases in global pasture area, cutting annual deforestation and related CO₂ emissions roughly in half, while also lowering methane emissions.