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December 14, 2023 Feature

The Climate Problem of Animal Agriculture: What Can Law, Technology, and We Do About It?

Daina Bray

As an undergraduate student at the University of North Carolina in the mid-1990s, I found two of my courses to be especially engaging but also unnerving: global environmental problems and sustainable agriculture. The first focused on three then-current issues: acid rain, the depletion of the ozone layer, and global warming. The second asked hard questions about how we would continue to feed our growing population without destroying the ecosystems that sustain us and left me with a lasting impression of complexity and risk.

Happily, as I write nearly 30 years later, two of the global environmental problems that we studied in the first course have been addressed. Through determined research to understand its causes, regulation of the responsible air pollutants, and transboundary cooperation, the acid rain crisis has been largely resolved.1 The Montreal Protocol on Substances That Deplete the Ozone Layer, which was finalized in 1987 and was the first treaty in the history of the United Nations to be universally ratified,2 was successful in putting the ozone layer on a path to recovery.3

But the planet is still very much warming. This summer saw record temperatures in the northern hemisphere, devastating fires in Canada and Hawaii, and flooding in Asia.4 While the Paris Agreement sets a goal of 1.5ºCelsius (C) warming above pre-industrial levels to avoid the worst consequences of climate change, the average temperature of the planet in 2022 was already 1.26ºC greater than the pre-industrial average.5 With 2023 expected to be the warmest year on record and likely in the last two thousand years, some scientists are starting to use words like “staggering” and “mind-boggling” to describe what may be an accelerating warming trend.6

The unsustainability of our industrial agriculture systems has also not been corrected since I was in college. According to a 2021 report from the UN Food & Agriculture Organization (FAO), almost one in ten of the world’s nearly 8 billion people were undernourished, and 3 billion people did not have healthy diets. With the population set to reach 9.7 billion by 2050, the FAO described the water and land resources used for farming as already at “breaking point.”7

Animal agriculture is at the fulcrum of these two thorny and persistent problems. On the (un)sustainability front, it is a massive consumer of resources. Animal agriculture (incorporating land used both for grazing and to grow animal feed) uses 77 percent of all global farming land, but produces only 18 percent of the calories and 37 percent of the protein that we consume.8 Animal agriculture also has an outsized water footprint. For example, in the United States, cattle feed crops alone are the single largest user of water, accounting for 23 percent of all national water usage.9 It takes 1,850 gallons of water to produce a pound of beef, 720 gallons for a pound of pork, 520 gallons for a pound of chicken, and substantially less for plants like soybeans, wheat, and corn, which use 256, 220, and 148 gallons respectively.10 Much of the environmental discrepancy between farming plants and animals comes down to the caloric inefficiency of feeding plants to animals, instead of eating plants.11 And animal agriculture has a fundamental climate problem.

Animal Agriculture and the Climate

Animal agriculture produces greenhouse gases (GHGs) in a number of ways, including via feed production, land use change, manure management, processing, transportation, and enteric fermentation (i.e., the natural process by which ruminant animals such as cattle and sheep digest carbohydrates and produce methane).12 Depending on assumptions and calculation methodology, animal agriculture has been estimated to be responsible for anywhere between 11 percent and 20 percent of all anthropogenic greenhouse gases.13 At either end of that range, animal agriculture’s emissions are massive and significant.

Animal agriculture’s impact is even greater in terms of the climate super-pollutants methane and nitrous oxide. Nitrous oxide—more than half of which comes from livestock, according to a UN estimate14—is around 280 times more powerful than carbon dioxide as a warming agent over its first 20 years in the atmosphere.15

Critically, animal agriculture is responsible for about a third of all global anthropogenic methane emissions,16 and it is the largest U.S. source of methane at 35.9 percent.17 Methane is about 80 times more potent than carbon dioxide during its first twenty years in the atmosphere.18 But, whereas carbon dioxide persists for hundreds of years, the average methane molecule persists in the atmosphere for only about a decade.19 This creates a substantial opportunity: reductions in methane in the coming years can play an important role in curbing warming. One of the lead reviewers of a 2021 Intergovernmental Panel on Climate Change report observed: “Cutting methane is the biggest opportunity to slow warming between now and 2040. We need to face this emergency.”20 Moreover, cutting carbon without action on super-pollutants including methane will preclude achievement of the Paris Agreement goals.21 To stabilize the climate in the near- and longer-term, we must do both things at once: decarbonize and reduce other climate super-pollutants.22

For these reasons, in this critical decade for climate action, many policy makers have turned their attention in earnest to methane mitigation. At COP26 in Glasgow in 2021, representatives of more than one hundred countries signed the “Global Methane Pledge,” undertaking to reduce methane emissions by 30 percent by 2030.23 But resulting policies have largely focused on regulating and reducing other sources of methane, such as landfills and leaky oil and gas pipelines, without seeking to limit livestock emissions. For example, in the United States, both the Biden administration’s Methane Action Plan and the Inflation Reduction Act imposed hard limits on methane emissions from other sources, but only voluntary and incentive-based approaches for methane from animal agriculture.24

Legal Solutions?

Despite animal agriculture’s substantial GHG contributions, the industry’s emissions remain largely unregulated around the world. In the United States, animal agriculture has been repeatedly exempted from air pollution rules.25 But policy action is beginning to move forward in some places, including countries and cities that have adopted policies for procurement of plant-based foods to reduce government emissions. Earlier this year, Taiwan passed a groundbreaking law requiring the government to promote and encourage climate-friendly diets, including plant-based foods.26 A climate law in France has required school cafeterias to provide vegetarian options in schools once a week since 2021.27 By joining the Good Food Cities Accelerator, sixteen cities around the world have undertaken to develop climate action plans that, among other steps, call for increased reliance on plant-based foods.28

Significantly, several European countries have proposed or taken steps to reduce herd sizes. The most prominent example is the Netherlands. The Court of Justice of the European Union (CJEU) ruled that nitrogen pollution from agriculture, including animal agriculture, in the Netherlands was violating the state’s obligation to protect wild areas, and ordered the government to reduce nitrogen emissions.29 Although the focus of the court judgment was on nitrogen pollution, subsequent Dutch government announcements emphasized the climate connection.30 The CJEU subsequently issued a similar decision as to Ireland’s failure to control nitrogen pollution,31 and experts say that the Irish government’s commitment to reducing GHG emissions by 25 percent by 2030 cannot be achieved without reducing the number of cattle in the country.32 In 2023 the European Commission approved €200 million in aid to buy out pig farmers in the Flanders region of Belgium to reduce nitrogen pollution.33

Two countries are also considering taxes relating to animal agriculture’s climate harms. In 2022, the government of New Zealand proposed the world’s first emissions tax on cattle,34 and the Danish Minister of Taxation recently shared that the government there is considering a beef tax after an advisory report called for a shift to plant-based foods to meet climate goals.35

These early efforts at direct regulation of animal agriculture’s emissions have faced significant pushback, including that the emissions tax proposal in New Zealand has been delayed.36 In the Netherlands, dramatic farmer protests featuring tractors in the streets and a significant political shake-up drew international attention.37

Where regulation is lacking, advocates may turn to litigation to influence public policy, hold companies accountable, and—as an ancillary effect—increase public awareness. There has been an explosion of climate litigation around the world, with nearly 2,200 cases filed by the end of 2022.38 A recent survey found that more than half of all decisions in climate-related lawsuits have been favorable to climate action.39 While most climate litigation to date has understandably focused on fossil fuel emissions, litigation activity is expanding to reach other heavy-emitting industries, including agriculture.40

Early lawsuits relating to animal agriculture’s climate responsibility have been filed. Leading cases include a consumer protection case in Denmark against the EU’s largest pork producer that had marketed a “climate-controlled pig,”41 a tort case in New Zealand brought by the climate change spokesperson for a Māori advocacy coalition against the country’s largest dairy producer (and others) seeking a declaration of liability and an injunction to limit GHG emissions,42 and a lawsuit in France alleging systemic environmental and human rights violations (including climate harms) in the supply chain of a large supermarket caused by livestock operations in Brazil and Colombia.43 A number of lawsuits in the United States have challenged government failures to consider the climate impacts of animal agriculture in regulatory decisions.44

There are good reasons to be skeptical about the ability of litigation to bring about the systemic and radical changes needed to avoid the worst effects of climate change.45 But, particularly because policy solutions are currently not sufficiently addressing the challenge and political obstacles abound, litigation can be a useful tool to increase the urgency and ambition of public and private actors and to increase awareness.46

Technology Solutions?

Rather than inviting regulation or acquiescing to climate liability (which perhaps no industry would be expected to do), many actors in the animal agriculture industry have instead looked to technological innovation to seek to respond to the climate problem of animal agriculture. Possible approaches include adjusting methods of growing animal feed, changing animal feed (including the use of feed additives), and improving manure management systems.47

Many of these approaches remain largely untested and their feasibility—including due to economic and cultural factors—uncertain.48 Because enteric fermentation in cattle is such a large part of livestock’s GHG emissions, there has been significant investment in that area. For example, using seaweed as a feed additive is being explored as a way to reduce methane emissions. But production of seaweed would need to be scaled up dramatically to support this approach and, anyway, it is only practical to feed additives to cattle when they are on feedlots rather than grazing, and U.S. beef cattle produce 89 percent of their methane while grazing.49 In one striking example of a proposed technological fix, the beef processing company Cargill has invested in a mask for cows to capture and oxidize methane as it is exhaled.50 It is unclear whether this approach would be scalable or effective. A recent study found (predictably) that the mask had negative welfare outcomes for cows, including skin abrasions and reduced social grooming.51

Other approaches may have unintended consequences. For example, some proposed mitigation strategies may reduce one type of emission but increase another—having a “pollution swapping” effect.52 Where mitigation approaches incentivize increasing productivity or keeping larger numbers of animals, they can have the effect of increasing absolute emissions.53 One prominent mitigation approach, already of growing prominence in the United States, is the use of biogas digesters.54 These systems capture methane from manure collected in large containers (euphemistically referred to as manure “lagoons”) to be used as fuel.55 While promoted by many in the industry as a sustainable improvement,56 biogas has been heavily criticized on a number of bases.57 Biogas is expensive, costing about four times more to produce than extracted gas, and the high up-front capital costs (including building the digester infrastructure and tying it in with existing gas pipelines) mean that it relies heavily on government subsidies and supports.58 The combination of subsidies, grants, and carbon trading have made biogas operations profitable59 and can incentivize growth and entrenchment of concentrated animal feeding operations (CAFOs).60 In addition, any suggestion that biogas could replace other sources of natural gas is misplaced: a 2019 study from the American Gas Foundation found that biogas from animal manure could, under the most aggressive scenario, meet only about 10 percent of U.S. residential demand for natural gas by 2040, and about 3 percent of total demand.61

An overarching concern with technological approaches to reducing GHG emissions from animal agriculture is that even a per-animal reduction in emissions (i.e., an improvement of emissions efficiency) can still result in increases in absolute emissions given current trends of increasing consumption of animal products.62 In other words, even a less climate-damaging individual animal may not be an improvement if the herd is growing.

An area of technological solutions that holds promise in relation to absolute emissions is the development of plant-based alternatives to animal products, such as improvements to taste and texture of alternatives, precision fermentation, and cultivated meat (i.e., meat produced directly from cells).63 Plant-based sales, while fluctuating in recent years, are growing.64 In June 2023, two companies received the first-ever approvals from the U.S. Department of Agriculture to produce and commercially market cultivated meat in the United States.65 Industry and government investment in such technologies, rather than further subsidization and growth of industrial animal agriculture, holds great promise.

Personal Responsibility?

Beyond legal and technological progress to tame animal agriculture’s climate harms, personal choice is central to dietary GHG emissions. For individuals with access to food choices, it is possible to dramatically reduce the climate footprint of our diets by consuming less or no animal products.66 Many experts say that making such choices is one of the most impactful things an individual can do to diminish their climate impact.67 This is one of the critical distinctions between fossil fuels and animal agriculture. As observed by Professor Jennifer Jacquet of New York University: “[There’s] a key difference between these industries: consumer preferences. Americans may not have much choice about the source of the electricity that lights their homes, but they do choose what to eat three times a day.”68

Such choices are particularly important in countries like the United States, which has one of the highest per capita levels of meat consumption in the world69 and bears huge responsibility for historical GHG emissions.70 For these reasons, in my view it is ethically sound for Americans with access to options to consider reducing their consumption of animal products.

Food choices are personal, influenced by our familial and cultural backgrounds as well as our values.71 I have made the decision not to consume animal products not only because of their climate impacts, but because of the array of externalized harms of the industrialized animal agriculture system (which produces the vast majority of animal food products in this country).72 A fulsome description of these harms is too long and grim a story for this article,73 but see the endnotes for resources to learn more about how industrial animal agriculture concentrates wealth and influence in the hands of a few74 while harming workers,75 environmental justice communities,76 animals,77 biodiversity,78 the environment,79 and the public health.80


* * * * *

Like so many complex challenges of our own making, the climate problem of animal agriculture does not have a single solution. Given the urgency of our planetary situation, it is imperative that we move forward on as many fronts as possible. Lawyers can work on policy and litigation. Scientists can develop technologies to help with a transition to a just and sustainable food system. At our kitchen tables and in our favorite restaurants, each of us makes several decisions a day that can help untangle the climate problem of animal agriculture. If we do these things, perhaps college students who are studying climate change today can look back—as I do on progress on acid rain and the ozone layer—and see that we made a difference. If we do not, I fear that widespread instability and suffering, visited most powerfully on the most vulnerable among us, will be the result.


1. Env’t Prot. Agency, Acid Rain & Related Programs: 2006 Progress Report 3–4, EPA-430-R-077-011 (2007); Tori B. Powell, What Happened to Acid Rain? How the Environmental Movement Won—and Could Again, CBS News (Apr. 22, 2022).

2. Env’t Prot. Agency, International Actions - The Montreal Protocol on Substances That Deplete the Ozone Layer (May 3, 2023).

3. Bruce Pasfield & Elise Paeffgen, How to Enforce a Carbon Tax: Lessons from the Montreal Protocol and the U.S. Experience with the Ozone Depleting Chemicals Tax, 14 Vt. J. Env’t L. 389, 394 (2013).

4. Press Release, Nat’l Aeronautics & Space Admin., NASA Announces Summer 2023 Hottest on Record (Sept. 14, 2023); Heather Chen, Soaring Temperatures to Record Rainfall: Asia Reels as Climate Crisis Takes Hold, CNN (July 17, 2023).

5. Climate Change Tracker, Indicators of Global Climate Change for Policy Makers.

6. Zeke Hausfather, Opinion: I Study Climate Change. The Data Is Telling Us Something New, N.Y. Times (Oct. 13, 2023); see also David Vetter, Scientists Issue New Warning as World Enters “Uncharted Climate Territory,” Forbes (Oct. 24, 2023).

7. U.N. Food & Agric. Org., The State of the World’s Land and Water Resources for Agriculture: Systems at Breaking Point 26, 32 (2021).

8. Hannah Ritchie, Half of the World’s Habitable Land Is Used for Agriculture, Our World in Data (Nov. 11, 2019).

9. Brian D. Richter et al., Water Scarcity and Fish Imperilment Driven by Beef Production, 3 Nature Sustainability 319, 320 (2020).

10. Water Footprint Calculator, Beef: The “King” of the Big Water Footprints (Jan 11, 2023).

11. E.g., Michael Dent, The Meat Industry Is Unsustainable, IDTechEx (Mar. 25, 2020), (“Chicken is the most efficient form of meat, but still requires 9 calories of energy to produce 1 calorie of meat and 5 g of protein to produce 1 g of protein. Pork is less efficient, requiring 10 calories of feed to produce 1 calorie of meat.”); see generally Frances Moore Lappé, Diet for a Small Planet (1971).

12. U.N. Food & Agric. Org., Tackling Climate Change Through Livestock xii, 20 (2013) [hereinafter FAO Tackling Climate Change].

13. Dan Blaustein-Rejto & Chris Gambino, Livestock Don’t Contribute 14.5% of Global Greenhouse Gas Emissions, Breakthrough Inst. (Mar. 20, 2023); see also Sophie Kevany, UN Numbers Say Meat Is Bad for the Climate. The Reality Is Worse, Vox (May 27, 2023).

14. FAO Tackling Climate Change, supra note 12, at 15 (relying on 2004 and 2005 data).

15. Piers Forster et al., The Earth’s Energy Budget, Climate Feedbacks and Climate Sensitivity, in Climate Change 2021: The Physical Science Basis. Contribution of Working Group I to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change 923, 1017 (Valérie Masson-Delmotte et al. eds., 2021).

16. U.N. Env’t Programme, Methane Emissions Are Driving Climate Change: Here’s How to Reduce Them (Aug. 20, 2021) [hereinafter UNEP, Methane Emissions].

17. Env’t Prot. Agency, Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990–2021 ES-19, EPA 430-R-23-002 (2023).

18. Forster et al., supra note 15, at 1017.

19. Env’t Prot. Agency, Understanding Global Warming Potentials (Apr. 18, 2023); UNEP, Methane Emissions, supra note 16.

20. Fiona Harvey, Reduce Methane or Face Climate Catastrophe, Scientists Warn, Guardian (Aug. 6, 2021); see also U.N. Env’t Programme, Global Methane Assessment 8 (2021),  (“Reducing human-caused methane emissions is one of the most cost-effective strategies to rapidly reduce the rate of warming and contribute significantly to global efforts to limit temperature rise to 1.5ºC.”).

21. Gabrielle B. Dreyfus et al., Mitigating Climate Disruption in Time: A Self-Consistent Approach for Avoiding Both Near-Term and Long-Term Global Warming, 119 Procs. Nat’l Acad. Scis. 1 (2022).

22. Tara Garnett et al., Grazed and Confused? Ruminating on Cattle, Grazing Systems, Methane, Nitrous Oxide, the Soil Carbon Sequestration Question—and What It All Means for Greenhouse Gas Emissions 120–21 (Food Climate Rsch. Network & Univ. of Oxford 2017).

23. Climate & Clean Air Coalition Secretariat, Global Methane Pledge.

24. White House Off. Domestic Climate Pol’y, U.S. Methane Emissions Reduction Action Plan 11–12 (Nov. 2021), (noting that animal agriculture “is a major source of methane emissions in the United States,” but including only voluntary and incentive-based animal agriculture policy proposals). The Inflation Reduction Act subsidizes “climate-smart” agriculture without imposing the new methane regulations targeted towards oil and gas. Gabriel Popkin, The Biden Administration Bets Big on “Climate Smart” Agriculture, Yale Env’t 360 (July 13, 2023); Jonathan L. Ramseur, Cong. Rsch. Serv., R47206, Inflation Reduction Act Methane Emissions Charge: In Brief 3-4 (Aug. 29, 2022).

25. Ryan Levandowski, Polluting ’til the Cows Come Home: How Agricultural Exceptionalism Allows CAFOs Free Range for Climate Harm, 33 Geo. Env’t L. Rev. 151 (2020); Shanna McCormack, Climate Change and Animal Agriculture: Federal Actions Protect the Biggest Contributors from the Disasters They Cause, 51 Env’t Law 745 (2021).

26. Taiwan’s Climate Legislation Embraces Plant-Based Eating, Env’t & Animal Soc’y of Taiwan (Jan. 12 2023).

27. Fiona Harvey, Outrage and Delight as France Ditches Reliance on Meat in Climate Bill, Guardian (May 29, 2021).

28. C40 Cities, Good Food Cities Accelerator.

29. Erik Stokstad, Nitrogen Crisis from Jam-Packed Livestock Operations Has “Paralyzed” Dutch Economy, Science (Dec. 4, 2019); Coöperatie Mobilisation for the Environment UA, ECLI:EU:C:2018:882, ¶¶ 69, 120.

30. Marit van der Hoek & Christopher Riker, Government Presents National Program to Reduce Nitrogen Greenhouse Gas Emissions in Rural Areas, U.S. Dep’t of Agric. Foreign Agric. Serv. (June 21, 2022).

31. European Commission v. Ireland, ECLI:EU:C:2023:524 at ¶ 117.

32. Declan Colley, Why Cattle Might Play a Major Role in Ireland’s Next National Election, Wash. Post (Feb, 7, 2023).

33. Belgium Has Approved the Purchase Program for Pig Farms, Tridge (Mar. 17, 2023).

34. New Zealand Ministry for the Env’t, Pricing Agricultural Emissions: Report under Section 215 of the Climate Change Response Act 2002 (Dec. 22, 2022).

35. Philip A. Churm, Tax Beef”—Denmark Finds Ways to Tackle Climate Change, Euronews (Aug. 29, 2023).

36. Rachel Pannett, How New Zealand Plans to Tackle Climate Change: Taxing Cow Burps, Wash. Post (Feb. 1, 2023).

37. Mongabay’s recent series on these events in the Netherlands is a fascinating and thought-provoking read. Ashoka Mukpo, The Dutch Farmers’ Protests of 2022, Mongabay (Sept. 14, 2023), .

38. U.N. Env’t Prog., Global Climate Litigation Report: 2023 Status Review 4 (July 27, 2023), [hereinafter UNEP 2023 Climate Litigation Report].

39. Joana Setzer & Catherine Higham, Global Trends in Climate Change Litigation: 2023 Snapshot, Grantham Rsch. Inst. 45 (June 2023).

40. E.g., Corbin Hiar, Fear of Climate Lawsuits Spreads Beyond Fossil Fuel Industry, E&E News (Mar. 27, 2023); Clark Mindock, The Newest Fronts in Climate-Change-Related Legal Battles, Reuters (Nov. 18, 2022).

41. Vegetarian Society of Denmark v Danish Crown, Sabin Ctr. for Climate Change Law: Climate Case Chart; Frances Schwartzkopff, First Danish Climate Lawsuit Targets EU’s Biggest Pork Producer, Bloomberg Green (June 4, 2021).

42. Smith v. Fonterra Coop. [2020] NZHC 419.

43. Assignation at 8, Envol Vert v. Casino Guichard-Perrachon, Saint-Étienne Judicial Court (2021) (Fr.).

44. E.g., Wash. State Dairy Fed. v. State, 18 Wash. App. 2d 259, 269–70 (2021); In re Daley Farms of Lewiston LLP, No. A19-0207, 2019 WL 5106666 (Minn. Ct. App. Oct. 14, 2019); Petition for Peremptory Writ of Mandate and Complaint for Declaratory & Injunctive Relief, Sierra Club et al. v. Cnty. of Tulare, No. 272380 (Cal. Super. Ct., filed Jan. 11, 2018).

45. E.g., Ben Batros & Tessa Khan, Thinking Strategically About Climate Change Litigation, in Litigating the Climate Emergency 97, 108 (César Rodríguez-Garavito ed., 2022) (recognizing that “problems with deep structural roots—like climate change—cannot simply be litigated away”); Leah Aronowsky, The Limits of Climate Change Litigation, N.Y. Rev. Books (Nov. 3, 2021).

46. UNEP 2023 Climate Litigation Report, supra note 38, at 7.

47. E.g., Junfang Zhao et al., A Review of Climate-Smart Agriculture: Recent Advancements, Challenges, and Future Directions, 15 Sustainability (2023); Felipe Montes et al., Special Topics – Mitigation of Methane & Nitrous Oxide Emissions from Animal Operations: II. A Review of Manure Management Mitigation Options, 91 J. Animal Sci. 5070 (2013).

48. E.g., Mario Herrero et al., Livestock and the Environment: What Have We Learned in the Past Decade?, 40 Ann. Rev. Env’t & Res. 177 (2015); Alexander N. Hristov et al., Mitigation of Greenhouse Gas Emissions in Livestock Production - A Review of Technical Options for Non-CO2 Emissions, U.N. Food & Agric. Org. 14–35, 125–28 (2013).

49. Sandra Vijn et al., Key Considerations for the Use of Seaweed to Reduce Enteric Methane Emissions from Cattle, 7 Front. Vet. Sci. 1, 2 (2020); Jan Dutkiewicz & Matthew Hayek, Want Carbon-Neutral Cows ? Algae Isn’t the Answer, Wired (Mar. 17, 2021).

50. Emma Bryce, Kowbucha, Seaweed, Vaccines: The Race to Reduce Cows’ Methane Emissions, Guardian (Sept. 30, 2021).

51. Stephanie Buijs et al., When the Measurement Affects the Object—Impact of a Multi-part Head/Neck Mounted Wearable Device on Dairy Cow Behavior, Health, and Productivity, 263 Applied Animal Behav. Sci. (2023).

52. E.g., Giampiero Grossi et al., Livestock and Climate Change: Impact of Livestock on Climate and Mitigation Strategies, 9 Animal Frontiers 69 (2019); Søren O. Petersen et al., Dietary Nitrate for Methane Mitigation Leads to Nitrous Oxide Emissions from Dairy Cows, 44 J. Env. Quality 1063 (2015).

53. E.g., Herrero et al., supra note 48.

54. Env’t Prot. Agency, AgSTAR Data and Trends, (July 7, 2023).

55. Sierra Club Guidance: Methane Digesters & Concentrated Animal Feeding Operation (CAFO) Waste, Sierra Club.

56. E.g., Smithfield Foods to Become Carbon Negative by 2030, Smithfield (Sept. 3, 2020).

57. E.g., Ruthie Lazenby, Rethinking Manure Biogas: Policy Considerations to Promote Equity & Protect the Climate & Environment, Ctr. Agric. Food Sys., Vt. L. Sch. (Aug. 2022); Environmental Groups Sound the Alarm on Delmarva Factory Farm Biogas Threat, Food & Water Watch (June 3, 2021).

58. Aaron Smith, What’s Worth More: A Cow’s Milk or Its Poop?, Ag Data News Blog (Feb. 3, 2021); Int’l Energy Agency, Outlook for Biogas and Biomethane: Prospects For Organic Growth 31, 37 (2020), (noting power grid connection and heat recovery distribution can increase costs by 70%); Phred Dvorak, California’s Green-Energy Subsidies Spur a Gold Rush in Cow Manure, Wall St. J. (Feb. 19, 2022).

59. Smith, supra note 58; Dvorak, supra note 58.

60. Alessandra Bergamin, Turning Cow Poop into Energy Sounds like a Good Idea—But Not Everyone Is on Board, Discover (Apr. 11, 2021); Feedback, Green Gas Without the Hot Air: Defining the True Role of Biogas in a Net Zero Future 57–60 (2020),  (describing how intensive factory farming of pigs and chickens expanded in Northern Ireland following the institution of biogas subsidies).

61. Renewable Sources of Natural Gas, Am. Gas Found. 8, 11 (2019).

62. Hannah Ritchie et al., Meat and Dairy Production, Our World in Data (Nov. 2019) [hereinafter Ritchie, Meat and Dairy Production].

63. The climate footprint of cultivated meat products will depend on technological developments and which processes are used. E.g., Casey Crownhart, Here’s What We Know About Lab-Grown Meat and Climate Change, MIT Tech. Rev. (July 3, 2023).

64. Megan Poinski, Plant-Based Sales Hit $8B in 2022, Food Dive (Apr. 11, 2023).

65. Kelly McCarthy, USDA Approves 1st Ever “Cell-Cultivated Meat” for 2 American Manufacturers, ABC News (June 22, 2023).

66. E.g., Michael B. Eisen & Patrick O. Brown, Rapid Global Phaseout of Animal Agriculture Has the Potential to Stabilize Greenhouse Gas Levels for 30 Years and Offset 68 Percent of CO2 Emissions This Century, PLOS Climate (Feb. 2022); Marta Kozicka et al., Feeding Climate and Biodiversity Goals with Novel Plant-Based Meat and Milk Alternatives, 14 Nature Commc’ns (2023); Plant-Rich Diets, Project Drawdown.

67. E.g., Seth Wynes & Kimberly A. Nicholas, The Climate Mitigation Gap: Education and Government Recommendations Miss the Most Effective Individual Actions, 12 Env’t Res. Letters 1, 7 (2017).

68. Jennifer Jacquet, The Meat Industry Is Doing Exactly What Big Oil Does to Fight Climate Action, Wash. Post (May 14, 2021).

69. Ritchie, Meat and Dairy Production, supra note 62.

70. Casey Crownhart, These Three Charts Show Who Is Most to Blame for Climate Change, MIT Tech. Rev. (Nov. 18, 2022).

71. A beautifully written and thought-provoking book on this topic is Eating Animals by Jonathan Safran Foer (2009).

72. Hannah Ritchie, How Many Animals Are Factory Farmed?, Our World in Data (Sept. 25, 2023).

73. See generally Pew Comm’n on Indus. Farm Animal Prod., Putting Meat on the Table: Industrial Farm Animal Production in America, Executive Summary (2008) (concluding that industrial farm animal production “systems are largely unregulated, and many practices common to this method of production threaten public health, the environment, animal health and well-being, and rural communities”).

74. E.g., Shefali Sharma, Mighty Giants: Leaders of the Global Meat Complex, Inst. for Agric. & Trade Pol’y (Apr. 10, 2018).

75. E.g., Dylan Matthews & Byrd Pinkerton, How Chicken Plants Became More Dangerous Places to Work Than Coal Mines, Vox (Oct. 7, 2020),  (citing U.S. Bureau Lab. Stats., Injuries, Illnesses, and Fatalities (2018)).

76. E.g., Corban Addison, Wastelands: The True Story of Farm Country on Trial (2022).

77. E.g., Nicholas Kristof, The Ugly Secrets Behind the Costco Chicken, N.Y. Times (Feb. 6, 2021).

78. E.g., U.N. Food & Agric. Org., The Impact of Livestock on Biodiversity 1 (2019) (“Livestock is among the sectors with highest impacts on biodiversity.”).

79. E.g., Delcianna J. Winders & Elan Abrell, Slaughterhouse Workers, Animals, and the Environment: The Need for a Rights-Centered Regulatory Framework in the United States That Recognizes Interconnected Interests, 23 Health Human Rts. 21 (2021).

80. E.g., Org. for Econ. Coop. & Dev., Anti-Microbial Resistance Is a Global Challenge for Food Systems and Public Health.

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Daina Bray

Yale Law School

Daina Bray is a clinical lecturer in law and senior research scholar at Yale Law School in New Haven, Connecticut. She is a graduate of Stanford Law School and of the University of North Carolina at Chapel Hill as a Morehead Scholar, and completed a Fulbright Scholarship in affiliation with the University of the West Indies–Mona’s Institute for Sustainable Development and the Jamaica Environment Trust. She is a member of the ABA House of Delegates and a past chair of the ABA TIPS Animal Law Committee, the ABA ILS International Animal Law Committee, and the Tennessee Bar Association Animal Law Section.