Environmental vegetarianism

Environmental vegetarianism is the practice of vegetarianism when motivated by the desire to create a sustainable diet that avoids the negative environmental impact of meat production. Livestock as a whole is estimated to be responsible for around 18% of global greenhouse gas emissions.[3][lower-alpha 1] As a result, significant reduction in meat consumption has been advocated by, among others, the Intergovernmental Panel on Climate Change in their 2019 special report[4] and as part of the 2017 World Scientists' Warning to Humanity.[5][6]

All types of meat—but especially lamb and beef—generate several times more greenhouse gas emissions in their production than fruit or vegetables.[1]
People in developed countries consume a substantially larger proportion of meat than those in developing countries.[2]

Other than climate change, environmental concerns about the production of animal products may also relate to pollution, deforestation, unsustainability and the use of water and land.[7][8][9]

Environmental impact of animal products
Main article: Environmental impact of meat production
See also: Food vs. feed

Four-fifths of agricultural emissions arise from the livestock sector.[10]

According to the 2006 Food and Agriculture Organization of the United Nations (FAO) report Livestock's Long Shadow, animal agriculture contributes on a "massive scale" to global warming, air pollution, land degradation, energy use, deforestation, and biodiversity decline.[11] The FAO report estimates that the livestock (including poultry) sector (which provides draft animal power, leather, wool, milk, eggs, fertilizer, pharmaceuticals, etc., in addition to meat) contributes about 18 percent of global GHG emissions expressed as 100-year CO2 equivalents.[lower-alpha 2] This estimate was based on life-cycle analysis, including feed production, land use changes, etc., and used GWP (global warming potential) of 23 for methane and 296 for nitrous oxide, to convert emissions of these gases to 100-year CO2 equivalents. The FAO report concluded that "the livestock sector emerges as one of the top two or three most significant contributors to the most serious environmental problems, at every scale from local to global".[11] The report found that livestock's contribution to greenhouse gas emissions was greater than that of the global transportation sector; this conclusion was criticized in 2010 by Frank Mitloehner of the University of California, Davis, who noted that the authors had not performed a similar life-cycle analysis for transportation, causing the relative contribution of animal agriculture to be overestimated.[12]

A 2009 study by the Worldwatch Institute argued that the FAO's report had underestimated impacts related to methane, land use and respiration, placing livestock at 51% of total global emissions.[13]

According to a 2002 paper:

The industrial agriculture system consumes fossil fuel, water, and topsoil at unsustainable rates. It contributes to numerous forms of environmental degradation, including air and water pollution, soil depletion, diminishing biodiversity, and fish die-offs. Meat production contributes disproportionately to these problems, in part because feeding grain to livestock to produce meat—instead of feeding it directly to humans—involves a large energy loss, making animal agriculture more resource intensive than other forms of food production. ... One personal act that can have a profound impact on these issues is reducing meat consumption. To produce 1 pound of feedlot beef requires about 2,400 gallons of water and 7 pounds of grain (42). Considering that the average American consumes 97 pounds of beef (and 273 pounds of meat in all) each year, even modest reductions in meat consumption in such a culture would substantially reduce the burden on our natural resources.[14]

The environmental impacts of animal production vary with the method of production, although "[overall] impacts of the lowest-impact animal products typically exceed those of vegetable substitutes".[7]

Methane

A 2017 study published in the journal Carbon Balance and Management found animal agriculture's global methane emissions are 11% higher than previous estimates, based on data from the Intergovernmental Panel on Climate Change.[15]

Land use

A 2003 paper published in the American Journal of Clinical Nutrition, after calculating effects on energy, land, and water use, concluded that meat-based diets require more resources and are less sustainable than lacto-ovo vegetarian diets.[16] "The water required for a meat-eating diet is twice as much needed for a 2,000-litre-a-day vegetarian diet".[17]

According to Cornell University scientists: "The heavy dependence on fossil energy suggests that the US food system, whether meat-based or plant-based, is not sustainable".[18] However, they also write: "The meat-based food system requires more energy, land, and water resources than the lactoovovegetarian diet. In this limited sense, the lactoovovegetarian diet is more sustainable than the average American meat-based diet."[18] One of these Cornell scientists has advised that the US could feed 800 million people with grain that livestock eat. He "depicted grain-fed livestock farming as a costly and nonsustainable way to produce animal protein", but "distinguished grain-fed meat production from pasture-raised livestock, calling cattle-grazing a more reasonable use of marginal land".[19]

Land degradation
We must change our diet. The planet can’t support billions of meat-eaters.

David Attenborough[20]

Another agricultural effect is on land degradation. Cattle are a known cause for soil erosion through trampling of the ground and overgrazing.[21] Much of the world's crops are used to feed animals.[22] With 30 percent of the earth's land devoted to raising livestock,[23] a major cutback is needed to keep up with growing population. Demand for meat is expected to double by 2050;[24] in China, for example, where vegetable-based diets were once the norm, demand for meat will continue to be great in absolute terms, even though demand growth will slow.[25] As countries are developing, incomes are increasing, and consumption of animal products is associated with prosperity. This growing demand is unsustainable.[26]

A grazing-based production can limit soil erosion and also allow farmers to control pests with less pesticides by rotating crops with grass. However, in arid areas, this may catalyze a desertification process. The ability of soil to absorb water by infiltration is important for minimizing runoff and soil erosion. Researchers in Iowa reported that a soil under perennial pasture grasses grazed by livestock was able to absorb far more water than the same kind of soil under two annual crops: corn and soybeans.[27][28]

Biodiversity loss

Biomass of mammals on Earth[29][30]

  Livestock, mostly cattle and pigs (60%)
  Humans (36%)
  Wild mammals (4%)

The 2019 IPBES Global Assessment Report on Biodiversity and Ecosystem Services found that the primary driver of biodiversity loss is human land use, which deprives other species of land needed for their survival, with the meat industry playing a significant role in this process. Around 25% of earth's ice-free land is used for cattle rearing.[31] Other studies have also warned that meat consumption is accelerating mass extinctions globally.[32][33][34] A 2017 study by the World Wildlife Fund attributed 60% of biodiversity loss to the land needed to rear tens of billions of farm animals.[35]

A May 2018 study stated that while wildlife has been decimated since the dawn of human civilization, with wild mammals plummeting by 83%, livestock populations reared by humans for consumption have increased.[36] Livestock make up 60% of the biomass of all mammals on earth, followed by humans (36%) and wild mammals (4%).[36] As for birds, 70% are domesticated, such as poultry, whereas only 30% are wild.[36][37]

Water

Animal production has a large impact on water pollution and usage. According to the Water Education Foundation, it takes 2,464 gallons of water to produce one pound of beef in California, whereas it takes only 25 gallons of water to produce one pound of wheat.[38] Raising a large amount of livestock creates a massive amount of manure and urine, which can pollute natural resources by changing the pH of water, contaminates the air, and emits a major amount of gas that directly affects global warming. As most livestock are raised in small confined spaces to cut down on cost, this increases the problem of concentrated waste. Livestock in the United States produces 2.7 trillion pounds of manure each year, which is ten times more than what is produced by the entire U.S. population. There are issues with how animal waste is disposed, as some is used as fertilizer while some farmers create manure lagoons which store millions of gallons of animal waste which is extremely unsafe and detrimental to the environment.[38]

Relation to other arguments
Massive reductions in meat consumption in industrial nations will ease the health care burden while improving public health; declining livestock herds will take pressure off rangelands and grainlands, allowing the agricultural resource base to rejuvenate. As populations grow, lowering meat consumption worldwide will allow more efficient use of declining per capita land and water resources, while at the same time making grain more affordable to the world's chronically hungry.[39]

Worldwatch Institute, an independent environmental research institute

Although motivations frequently overlap, environmental vegetarians and vegans can be contrasted with those who are primarily motivated by concerns about animal welfare (one kind of ethical vegetarianism), health, or who avoid meat to save money or out of necessity (economic vegetarianism).[40][41] Some also believe vegetarianism will improve global food security, or curb starvation.

Health

A study in Climate Change concluded "if ... average diets among UK adults conformed to WHO recommendations, their associated GHG emissions would be reduced by 17%. Further GHG emission reductions of around 40% could be achieved by making realistic modifications to diets so that they contain fewer animal products and processed snacks and more fruit, vegetables and cereals."[42] A study in The Lancet estimated that the "30% reduction in livestock production" by 2030 required to meet the UK Committee on Climate Change's agricultural would also result in a roughly 15% decrease in ischaemic heart disease.[10]

Environmental vegetarians call for a reduction of first world consumption of meat, especially in the US. According to the United Nations Population Fund, "Each U.S. citizen consumes an average of 260 lbs. of meat per year, the world's highest rate. That is about 1.5 times the industrial world average, three times the East Asian average, and 40 times the average in Bangladesh."[43] In addition, "the ecological footprint of an average person in a high-income country is about six times bigger than that of someone in a low-income country, and many more times bigger than in the least-developed countries".[44]

A 2018 report published in PNAS asserted that farmers in the United States could sustain more than twice as many people than they do currently if they abandoned rearing farm animals for human consumption and instead focused on growing plants.[45]

The World Health Organization calls malnutrition "the silent emergency", and says that it is a factor in at least half of the 10.4 million child deaths which occur every year.[46][47] Some argue that the adoption of an ovo-lacto vegetarian or entirely plant-based vegan diet is best, but may not be totally necessary, because even modest reductions in meat consumption in industrialized societies would substantially reduce the burden on natural resources. For developed countries, a CAST report estimates an average of 2.6 pounds of grain feed per pound of beef carcass meat produced. For developing countries, the estimate is 0.3 pounds per pound. (Some very dissimilar figures are sometimes seen; the CAST report discusses common sources of error and discrepancies among such figures.)[48] In 2007, US per capita beef consumption was 62.2 pounds per year, and US per capita meat (red meat plus fish plus poultry) consumption totaled 200.7 pounds (boneless trimmed weight basis).[49]

Support

Globalization and modernization has resulted in Western consumer cultures spreading to countries like China and India, including meat-intensive diets which are supplanting traditional plant-based diets. More than 200 billion animals are consumed by a global population of over 7 billion annually, which philosopher and animal rights activist Steven Best argues is "completely unsustainable".[50] A 2018 study published in Science states that meat consumption is set to increase by some 76% by 2050 as the result of human population growth and rising affluence, which will increase greenhouse gas emissions and further reduce biodiversity.[51]

A 2018 report in Nature found that a significant reduction in meat consumption is necessary to mitigate climate change, especially as the population rises to a projected 10 billion in the coming decades.[52] According to a 2019 report in The Lancet, global meat consumption needs to be reduced by 50 percent to mitigate for climate change.[53]

In November 2017, 15,364 world scientists signed a Warning to Humanity calling for, among other things, drastically diminishing our per capita consumption of meat.[54]

A 2010 report from the United Nations Environment Programme's (UNEP) International Panel of Sustainable Resource Management stated:

Impacts from agriculture are expected to increase substantially due to population growth and increasing consumption of animal products. Unlike fossil fuels, it is difficult to look for alternatives: people have to eat. A substantial reduction of impacts would only be possible with a substantial worldwide diet change, away from animal products.[55][22]

The aforementioned Global Assessment Report on Biodiversity and Ecosystem Services also suggested that a reduction in meat consumption would be required to help preserve biodiversity.[31]

According to a July 2019 report by the World Resources Institute the global population will increase to roughly 10 billion by the middle of the century, with demand for ruminant meat rising by 88%. The report posits that Americans and Europeans will need to reduce their beef consumption by 40% and 22% respectively in order to feed so many people and at the same time avert an ecological catastrophe.[56]

In November 2019, a warning on the "climate emergency" from over 11,000 scientists from over 100 countries said that "eating mostly plant-based foods while reducing the global consumption of animal products, especially ruminant livestock, can improve human health and significantly lower GHG emissions (including methane in the “Short-lived pollutants” step)." The warning also says it this will "free up croplands for growing much-needed human plant food instead of livestock feed, while releasing some grazing land to support natural climate solutions."[57][58]

A 2020 study by researchers from the University of Michigan and Tulane University, which was commissioned by the Center for Biological Diversity, asserts that if the U.S. cut its meat consumption by half, it could result in diet-related GHG emissions being reduced by 35%, a decline of 1.6 billion tons.[59]

Criticism

Bill Mollison has argued in his Permaculture Design Course that vegetarianism exacerbates soil erosion. This is because removing a plant from a field removes all the nutrients it obtained from the soil, while removing an animal leaves the field intact. On US farmland, much less soil erosion is associated with pastureland used for livestock grazing than with land used for production of crops.[60] Robert Hart has also developed forest gardening, which has since been adopted as a common permaculture design element, as a sustainable plant-based food production system.[61]

Some environmental activists claim that adopting a vegetarian diet may be a way of focusing on personal actions and righteous gestures rather than systemic change. Environmentalist Dave Riley states that "being meatless and guiltless seems seductively simple while environmental destruction rages around us", and notes that Mollison "insists that vegetarianism drives animals from the edible landscape so that their contribution to the food chain is lost".[62]

According to a study published in PNAS, U.S. GHG emissions would only be decreased by 2.6% (or 28% of agricultural GHG emissions) if animals were completely removed from U.S. agriculture and diets.[63] This study's underlying assumptions however were heavily criticized.[64][65][66] In a followup letter the authors refuted the criticism and defended their work.[67]

See also

Notes
  1. This is in line with the FAO's earlier estimate of 18%, published in Livestock's Long Shadow in 2006. They caution that "the two figures cannot be accurately compared, as reference periods and sources differ."
  2. This is in line with the FAO's more recent figure of 14.5 percent. They caution that "the two figures cannot be accurately compared, as reference periods and sources differ."[3]

References
  1. Stephen Clune; Enda Crossin; Karli Verghese (1 January 2017). "Systematic review of greenhouse gas emissions for different fresh food categories" (PDF). Journal of Cleaner Production. 140 (2): 766–783. doi:10.1016/j.jclepro.2016.04.082.
  2. "FAOSTAT" (PDF). faostat.fao.org.
  3. "Key facts and findings". Food and Agriculture Organization. Retrieved 29 April 2019.
  4. Schiermeier, Quirin (August 8, 2019). "Eat less meat: UN climate change report calls for change to human diet". Nature. Retrieved August 10, 2019.
  5. "Climate change food calculator: What's your diet's carbon footprint?". 13 December 2018. Retrieved 30 April 2019.
  6. Ripple WJ, Wolf C, Newsome TM, Galetti M, Alamgir M, Crist E, Mahmoud MI, Laurance WF (13 November 2017). "World Scientists' Warning to Humanity: A Second Notice". BioScience. 67 (12): 1026–1028. doi:10.1093/biosci/bix125.
  7. Nemecek, T.; Poore, J. (2018). "Reducing food's environmental impacts through producers and consumers". Science. 360 (6392): 987–992. Bibcode:2018Sci...360..987P. doi:10.1126/science.aaq0216. ISSN 0036-8075. PMID 29853680.
  8. Bittman, Mark (27 January 2008). "Rethinking the Meat-Guzzler". The New York Times. Retrieved 8 November 2017 – via www.nytimes.com.
  9. Carrington, Damian (10 October 2018). "Huge reduction in meat-eating 'essential' to avoid climate breakdown". The Guardian. Retrieved 30 April 2019.
  10. Friel, Sharon (2009). "Public health benefits of strategies to reduce greenhouse-gas emissions: food and agriculture". The Lancet. 374 (9706): 2016–2025. doi:10.1016/S0140-6736(09)61753-0. PMID 19942280. S2CID 6318195.
  11. Steinfeld, Henning; Gerber, Pierre; Wassenaar, Tom; Castel, Vincent; Rosales, Mauricio; de Haan, Cees (2006), Livestock's Long Shadow: Environmental Issues and Options (PDF), Rome: FAO
  12. Black, Richard (2010-03-24). "UN body to look at meat and climate link". BBC.
  13. "Study claims meat creates half of all greenhouse gases". 1 November 2009.
  14. Horrigan, Leo; Lawrence, Robert S; Walker, Polly (May 2002). "How Sustainable Agriculture Can Address the Environmental and Human Health Harms of Industrial Agriculture". Environmental Health Perspectives. 110 (5): 445–456. doi:10.1289/ehp.02110445. PMC 1240832. PMID 12003747.
  15. Wolf, Julie; Asrar, Ghassem R.; West, Tristram O. (September 29, 2017). "Revised methane emissions factors and spatially distributed annual carbon fluxes for global livestock". Carbon Balance and Management. 12 (16): 16. doi:10.1186/s13021-017-0084-y. PMC 5620025. PMID 28959823.
  16. Pimentel, David; Pimentel, Marcia (1 September 2003). "Sustainability of meat-based and plant-based diets and the environment". The American Journal of Clinical Nutrition. 78 (3): 660S–663S. doi:10.1093/ajcn/78.3.660s. PMID 12936963.
  17. "Solution for the world's water woes: Rising populations and growing demand is making the world a thirsty planet; the solution lies in people reducing the size of their "water footprints" - Water Education Foundation". www.watereducation.org. Retrieved 2017-04-03.
  18. Pimentel, David; Pimentel, Marcia (September 2003). "Sustainability of meat-based and plant-based diets and the environment". American Journal of Clinical Nutrition. 78 (3): 660S–663S. doi:10.1093/ajcn/78.3.660S. PMID 12936963.
  19. "U.S. could feed 800 million people with grain that livestock eat, Cornell ecologist advises animal scientists". Cornell Chronicle. August 7, 1997. Retrieved 19 July 2015.
  20. Dalton, Jane (August 26, 2020). "Go vegetarian to save wildlife and the planet, Sir David Attenborough urges". The Independent. Retrieved August 27, 2020.
  21. C.Michael Hogan. 2009. Overgrazing. Encyclopedia of Earth. Sidney Draggan, topic ed.; Cutler J. Cleveland, ed., National council for Science and the Environment, Washington DC
  22. Carus, Felicity (2010-06-02). "UN urges global move to meat and dairy-free diet". The Guardian. Retrieved 2011-10-26.
  23. "Livestock Grazing- Combats or Spreads Desertification?". Archived from the original on 2007-07-01.
  24. "Meat production continues to rise". Worldwatch Institute. October 18, 2018. Retrieved October 18, 2018.
  25. "Rabobank: China's Animal Protein Outlook to 2020: Growth in Demand, Supply and Trade". Rabobank. March 2, 2017. Retrieved October 18, 2018.
  26. "Sustainability Pathways: Sustainability and livestock". www.fao.org. Retrieved 2017-04-03.
  27. Bharati et al. 2002. Agroforestry Systems 56: 249-257
  28. "Tobacco | Land & Water | Food and Agriculture Organization of the United Nations | Land & Water | Food and Agriculture Organization of the United Nations". www.fao.org. Retrieved 2019-01-31.
  29. Damian Carrington, "Humans just 0.01% of all life but have destroyed 83% of wild mammals – study", The Guardian, 21 May 2018 (page visited on 19 August 2018).
  30. Baillie, Jonathan; Zhang, Ya-Ping (2018). "Space for nature". Science. 361 (6407): 1051. Bibcode:2018Sci...361.1051B. doi:10.1126/science.aau1397. PMID 30213888.
  31. Watts, Jonathan (May 6, 2019). "Human society under urgent threat from loss of Earth's natural life". The Guardian. Retrieved May 18, 2019.
  32. Morell, Virginia (August 11, 2015). "Meat-eaters may speed worldwide species extinction, study warns". Science. Retrieved May 18, 2019.
  33. Machovina, B.; Feeley, K. J.; Ripple, W. J. (2015). "Biodiversity conservation: The key is reducing meat consumption". Science of the Total Environment. 536: 419–431. Bibcode:2015ScTEn.536..419M. doi:10.1016/j.scitotenv.2015.07.022. PMID 26231772.
  34. Woodyatt, Amy (May 26, 2020). "Human activity threatens billions of years of evolutionary history, researchers warn". CNN. Retrieved May 27, 2020. Research showed that among the biggest threats to threatened species was eating meat, Gumbs said.
  35. Smithers, Rebecca (October 5, 2017). "Vast animal-feed crops to satisfy our meat needs are destroying planet". The Guardian. Retrieved May 18, 2019.
  36. Bar-On, Yinon M; Phillips, Rob; Milo, Ron (2018). "The biomass distribution on Earth". Proceedings of the National Academy of Sciences. 115 (25): 6506–6511. doi:10.1073/pnas.1711842115. PMC 6016768. PMID 29784790.
  37. Carrington, Damian (May 21, 2018). "Humans just 0.01% of all life but have destroyed 83% of wild mammals – study". The Guardian. Retrieved May 23, 2018.
  38. admin (2007-04-04). "The Environmental Impact of a Meat-Based Diet". Vegetarian Times. Retrieved 2017-04-03.
  39. United States Leads World Meat Stampede | Worldwatch Institute Archived May 17, 2008, at the Wayback Machine
  40. Nuwer, Rachel. "What would happen if the world suddenly went vegetarian?". www.bbc.com. BBC. Retrieved 30 April 2019.
  41. Katherine Manning. "Eat Better and Improve Your Health For Less Money". Archived from the original on 14 November 2012. Retrieved 10 February 2013.
  42. Green, Rosemary (2015). "The potential to reduce greenhouse gas emissions in the UK through healthy and realistic dietary change". Climatic Change. 129 (1–2): 253–265. Bibcode:2015ClCh..129..253G. doi:10.1007/s10584-015-1329-y. S2CID 154322542.
  43. "UNFPA - United Nations Population Fund". www.unfpa.org. Archived from the original on 2003-04-28.
  44. "State of World Population 2004 - UNFPA - United Nations Population Fund". www.unfpa.org.
  45. Kaplan, Karen (26 March 2018). "By going vegan, America could feed an additional 390 million people, study suggests". Los Angeles Times. Archived from the original on 30 March 2018. Retrieved 29 March 2018. If U.S. farmers took all the land currently devoted to raising cattle, pigs and chickens and used it to grow plants instead, they could sustain more than twice as many people as they do now, according to a report published Monday in the Proceedings of the National Academy of Sciences.
  46. "Hungry world 'must eat less meat'". BBC News. August 16, 2004. Retrieved May 2, 2010.
  47. http://www.tradeobservatory.org/library.cfm?refID=48538 Archived April 5, 2005, at the Wayback Machine
  48. Bradford, E. et al. 1999. Animal Agriculture and Global Food Supply. Council on Agricultural Science and Technology. 92 pp.
  49. USDA. 2010. Agricultural Statistics 2010, Table 13-7
  50. Best, Steven (2014). The Politics of Total Liberation: Revolution for the 21st Century. Palgrave Macmillan. p. 97. ISBN 978-1137471116.
  51. Devlin, Hannah (July 19, 2018). "Rising global meat consumption 'will devastate environment'". The Guardian. Retrieved September 23, 2019.
  52. Achenbach, Joel (October 10, 2018). "Earth's population is skyrocketing. How do you feed 10 billion people sustainably?". The Washington Post. Retrieved October 16, 2018.
  53. Gibbens, Sarah (January 16, 2019). "Eating meat has 'dire' consequences for the planet, says report". National Geographic. Retrieved January 21, 2019.
  54. Ripple WJ, Wolf C, Newsome TM, Galetti M, Alamgir M, Crist E, Mahmoud MI, Laurance WF (13 November 2017). "World Scientists' Warning to Humanity: A Second Notice". BioScience. 67 (12): 1026–1028. doi:10.1093/biosci/bix125.
  55. Assessing the Environmental Impacts of Consumption and Production: Priority Products and Materials (PDF), UNEP, 2010, p. 82, retrieved 17 July 2015
  56. Christensen, Jen (July 17, 2019). "To help save the planet, cut back to a hamburger and a half per week". CNN. Retrieved October 5, 2020.
  57. Ripple, William J.; Wolf, Christopher; Newsome, Thomas M; Barnard, Phoebe; Moomaw, William R (November 5, 2019). "World Scientists' Warning of a Climate Emergency". BioScience. doi:10.1093/biosci/biz088. hdl:1808/30278. Retrieved November 8, 2019.
  58. Carrington, Damian (November 5, 2019). "Climate crisis: 11,000 scientists warn of 'untold suffering'". The Guardian. Retrieved November 8, 2019.
  59. Germanos, Andrea (April 30, 2020). "Slashing US Meat Consumption by Half Could Cut Diet-Related Greenhouse Gas Emissions by 35%: Study". Common Dreams. Retrieved May 8, 2020.
  60. NRCS. 2009. Summary report 2007 national resources inventory. USDA Natural Resources Conservation Service. 123 pp.
  61. Robert Hart (1996). Forest Gardening. p. 45. ISBN 9781603580502.
  62. "Does meat make the meal?". 2016-09-05.
  63. White, Robin R.; Beth Hall, Mary (November 13, 2017). "Nutritional and greenhouse gas impacts of removing animals from US agriculture". Proceedings of the National Academy of Sciences. 114 (48): E10301–E10308. doi:10.1073/pnas.1707322114. PMC 5715743. PMID 29133422.
  64. Van Meerbeek, Koenraad; Svenning, Jens-Christian (February 12, 2018). "Causing confusion in the debate about the transition toward a more plant-based diet". Proceedings of the National Academy of Sciences. 115 (8): E1701–E1702. doi:10.1073/pnas.1720738115. PMC 5828628. PMID 29440444.
  65. Springmann, Marco; Clark, Michael; Willett, Walter (February 20, 2018). "Feedlot diet for Americans that results from a misspecified optimization algorithm". Proceedings of the National Academy of Sciences. 115 (8): E1704–E1705. doi:10.1073/pnas.1721335115. PMC 5828635. PMID 29440445.
  66. Shepon, Alon; Eshel, Gidon; Noor, Elad; Milo, Ron (February 20, 2018). "The opportunity cost of animal based diets exceeds all food losses". Proceedings of the National Academy of Sciences. 115 (15): 3804–3809. doi:10.1073/pnas.1713820115. PMC 5899434. PMID 29581251.
  67. White, Robin R.; Beth Hall, Mary (February 20, 2018). "Reply to Van Meerbeek and Svenning, Emery, and Springmann et al.: Clarifying assumptions and objectives in evaluating effects of food system shifts on human diets". Proceedings of the National Academy of Sciences. 115 (8): E1706–E1708. doi:10.1073/pnas.1720895115. PMC 5828631. PMID 29440443.
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