Policy and law: the case of synthetic nitrogen fertilizer

Agriculture occupies more than a third of the world’s land with many, large-scale impacts on the environment and human health. This article investigates the failure of policy to manage these impacts, asks whether private law can fill the gap, and what this means for policymakers. The investigation takes the form of a case study of synthetic nitrogen fertilizer (SNF) in English policy and law. The SNF industry has been chosen because, by its own account, it underpins the modern food system, which is recognized as needing urgent transformation. The article first assesses the damage caused by SNF to health and the environment and the potential legal remedies. It then assesses industry claims that SNF (a) provides food security, (b) is beneficial to soil and water, and (c) reduces greenhouse gas emissions. If misleading, these representations could amount to unlawful ‘greenwashing’. While private law can never replace good policy and regulation, the article concludes that there is evidence to enable private law to supplement policy, and that this role is made possible as well as necessary by the absence of effective regulation and enforcement. Private litigation could catalyze policymakers to implement the robust regulatory regime that agriculture demands. As the law must focus on scientific evidence and causation, it can also help elucidate and publicize the science on which policy is based. Finally, because of the strict constraints within which private litigation must operate, it can direct policymakers towards strategic interventions (or tipping points) that could catalyze systemic change.


Introduction
Both the United Nations and World Bank regard a transformation of the food system as urgently needed (United Nations 2021, World Bank 2023).The role of agriculture in recent pandemics adds a new imperative (Atiles and Whyte 2023, 240).Agriculture is not only a source of food, employment and economic activity, but also occupies more than a third of the world's land (FAO 2020).Because of its importance, impacts and complexities, agriculture represents a challenge to policymakers (Gunningham 1998, chap. 5).This challenge is exemplified by the growth of SNF, whose history documents how policy has been deployed (or subverted) to produce today's farming system (Smil 2001, Johnson 2016, Stone 2022a).
Policy failure is an international phenomenon.In the EU, the Nitrates Directive (1991) and the Water Framework Directive (2000) have failed to deliver the requisite reductions in SNF pollution.A new Nutrients Directive has been proposed as essential for the EU to achieve the objectives of the new Farm to Fork strategy which calls for nutrient losses to the environment to be reduced by 50%, and for SNF use to be reduced by 20%, by 2030 (Wassen et al 2022, 287).While China has begun to take steps to address its historically profligate use of SNF, the search continues for the right mixture of policies (Wang et al 2023).Relying on voluntary efforts by farmers to protect the environment has long been recognized as inadequate (Winter 1991), leading to calls in the United States for measures to force the SNF industry to improve product efficiency as auto manufacturers have had to improve their fuel efficiency (Kanter andSearchinger 2018, Kanter et al 2020).
These measures, however, lie in the future and illustrate the gap that exists today.This paper therefore asks whether private law could help fill that gap or stimulate action by policymakers and regulators.The research takes the form of a case study of SNF.The scientific analysis is global, with supplementary evidence about policy, law and impact in England.The choice of England for the case study has an objective as well as a subjective basis.First, the impacts of nutrient pollutants are well-documented, including by government agencies, which creates a clear evidence base.Second, the legal system is recognizable in many other common law jurisdictions.Civil law and other jurisdictions, as well as the European Union, have different legal frameworks, but the science and evidential approach are likely to be relevant across all jurisdictions.

Policy, strategy and law
While private law operates differently to policy and regulation, it should be founded on the same principles of evidence, science and context (Stuart-Smith et al 2021).Science and law share a critical emphasis on causation (Minnerop and Otto 2020).Like policy, the law needs to consider both detail and social and political context (Bogojević 2023, 2).Critically, however, the courts are reluctant to undertake discussions of policy trade-offs and cost-benefit analyses, so litigation must focus on concrete and specific claims of harm.Also, if litigation is to have a systemic impact, it must be strategic and targeted.This discipline may help guide policymakers towards strategic thinking.For example, SNF pollution needs to be tackled not only for the damage it causes directly, but also because a forced reduction of SNF over a short transition period would lead to other essential system changes, notably a reduction in food waste (Gustavsson et al 2011) and healthier diets (Schulte- Uebbing et al 2022, 507-12, 509).
The deployment of litigation in this way can be described generically as a political-legal strategy (Kotzé and Knappe 2023, 2).When it aims to achieve systemic change through a non-linear intervention, it can be understood as 'forcing' (Sharpe and Lenton 2021, 422), as a 'positive tipping point' (Lenton et al 2022) or a 'sensitive intervention point' (SIP) (Farmer et al 2019, 41-42, Mealy et al 2023).Law and policy intersect most strongly where both are addressing the common good, such as the environment (Vermeule 2022, 18).Often this means articulating a better alternative to the status quo.In this case, the 'better way' is provided by agroecological 'techniques that contribute to a more environmentally friendly, ecological, organic or alternative agriculture' (Wezel et al 2009, 511).Private law can be seen as a policy resource for those seeking an agroecological approach to farming and food (Fisher 2022).This pattern has long been recognized in court.New technologies emerge and science and law catch up.If necessary, the common law can develop a new duty of care and a higher standard on those creating hazards to property and life (Pollock 1904, 124-26).Just as policymakers can create new legal opportunities (Vanhala 2018), so legal developments may influence the 'policy opportunity structure'.In addition, good environmental policy design incorporates multiple approaches rather than relying on one (Gunningham and Sinclair 1999).
The potential causes of action are the torts of negligence and nuisance, and the emerging field of 'greenwashing'.Claims in negligence and nuisance require proof of the damage that SNF does to the environment and human health.Thus, we start with an analysis of the science of SNF to establish the essential elements of negligence and nuisance.The English common law tort of negligence rises from the failure of the defendant to exercise the care demanded by the circumstances, causing damage to the plaintiff. 1It is not necessary that the act or omission of the defendant is the sole or even dominant cause of the damage. 2The limiting factor is whether the defendant owes a duty of care to the plaintiff, which arises when the plaintiff is in the area of objectively foreseeable danger. 3There is an analogy here with the tobacco and opioids industries, given the widespread damage caused to public health.
The common law tort of private nuisance arises when the defendant does something on their land which causes damage to the plaintiff's private property rights and enjoyment of their own land.Public nuisance arises when the damage is done to the public as a whole, or to a class of the public, and the plaintiff has suffered as a result.An example of private nuisance is where the defendant manufactures or uses a chemical on their property which causes damage to the air, water, or soil on the plaintiff's property. 4An example of public nuisance is allowing chemicals into a river which then affect the use of the river for fishing, boating, swimming or water extraction.Unlike in negligence, damages for personal injury cannot be recovered in private nuisance,5 but illhealth is evidence of a nuisance. 6The main remedies for nuisance are damages and/or an injunction.English and American law have taken different paths on strict liability where hazardous activities and substances are involved (Waite 2006, 441).Several torts have been used in litigation against fossil fuel companies in the US and could be used against diffuse N pollution there (Riddle 2020, 97).Nuisance was successfully deployed against nutrient pollution (from intensive poultry units) in State of Oklahoma v Tyson Foods and Others.7 Nitrogen: global and local policy failure and impacts Nitrogen (N) is an essential nutrient for plants (Ladha et al 2005).It was discovered in the 1700s, and its operations in plants first described the following century (Galloway et al 2013).Crops such as wheat, maize and rice take up most of their N from the soil (Griesheim et al 2019, Quinn 2023).Legumes such as clover, soybean, and peanuts convert atmospheric N to biologically fixed nitrogen (BFN) (Peoples et al 2019, 128).
There are two broad methods for increasing the N available to plants, which began to be documented and formalized in early modern Europe, for example by agricultural reformers in mid-seventeenth century England (Webster 1975, Thirsk 1985).The first was the traditional 'agroecological' approach that promoted BFN using legumes such as clover.The second was an emerging 'agrichemical' approach that sought ways to manufacture synthetic sources of N. The agrichemical path led ultimately to the industrial-scale manufacture of ammonia (NH 3 ) in 1913 using the Haber-Bosch method.This method of production continues to expand: agricultural use of SNF grew 40% from 2010 to 2020 (FAO 2022, 9) and provides ∼29% of the annual fixation of reactive N (Nr) to biological systems and soils (Fowler et al 2013, 4).
The central problem is that <50% of the Nr in SNF is absorbed by crops: 36% for cereal grain production (Mulvaney, Khan, and Ellsworth 2009, 2295-2314); and ∼31% for rice produced in Asian continuous irrigated rice systems (Cassman et al 2002, 133).The Nr surplus ends up in the atmosphere, ecosystems, surface water and groundwater and the sea.It causes pollution, biodiversity loss, and harm to human health (Sutton et al 2011).Elevated nitrate (NO 3 ) in drinking water causes ill-health in humans, including bowel cancer and 'blue baby syndrome'.Nitrates cause algal blooms and dead zones in fresh and coastal waters.Nitrogen oxides (NO x ) from over-fertilized agricultural soils damage air quality and cause ozone depletion, while nitrous oxide (N 2 O) from the same source is a GHG ∼273 times more powerful than carbon dioxide (CO 2 ) over 100 years (Galloway et al 2013) The effects on biodiversity were noted even in the 1800s (Huber and Watson 1974, Tabashnik 1982, Smil 2001, Reay 2015, 86).
The agricultural N surplus is now very close to exceeding planetary boundaries for damage to groundwater and terrestrial and aquatic biodiversity (Rockström et al 2023).Globally, at least one threshold (mostly groundwater) has been exceeded in 66% of all agricultural land and 71% of arable land (Schulte-Uebbing et al 2022, 509 and Extended Data table 1).Nearly half of agricultural land is in areas where the threshold for N load to surface water is already exceeded by non-agricultural sources such as sewage (Schulte- Uebbing et al 2022, 509).
SNF contributes to GHG emissions in three ways: (1) in its production, from fossil fuels; (2) in its transport and application, from vehicles powered by fossil fuels; and (3) in the emissions of nitrous oxide (N 2 O) from agricultural land, which account for ∼9% of total global GHG emissions (Peoples et al 2019, 132).While elevated atmospheric CO 2 may increase the rate of sequestration of carbon into agricultural soils, in SNF-treated soils any such increase will be almost completely offset by higher N 2 O emissions (Dijkstra and Morgan 2012).Nitrous oxides have other negative atmospheric effects (Erisman et al 2008).
Ammonia (NH 3 ) is a toxic gas at high concentrations.Worldwide, >80% of ammonia emissions come from agricultural activities (Wyer et al 2022).SNF contributes directly as a source of ammonia and indirectly through its role in animal production.A 50% reduction in agricultural emissions could reduce mortality attributable to air pollution by ∼250,000 a year worldwide; in Europe this would reduce deaths by 52,000 (19%) a year (Pozzer et al 2017).In England, however, ammonia emissions have been rising, with 'potentially significant implications for biodiversity and human health' (EA 2021, 15).
In England, ∼69% of land is used for agriculture.Of this, 55% is cropland and 40% pasture, with wheat and barley accounting for half of the cropland (DEFRA 2022b).Almost all wheat and barley fields and over half of pasture fields are treated with SNF (DEFRA 2022a, tbl.EW1.1).Some 687,000 t N was applied in England and Wales in 2022, 14% less than in 2021, because of higher prices caused by the Ukraine war.Nonetheless, wheat and barley yields rose from the 2021 to 2002 crop years, by 10% and 9% respectively (DEFRA 2022c).
Potentially relevant to policy and legal causation is the lag in N flow from leaching to riverine loads which one study found to average 4.5 years with a range of one to 12 years (McDowell et al 2021).However, there has been a high degree of stability in SNF application in England over five and 12 years, excluding the 2022 wartime dip.This means that the lag effect has not influenced the nutrient load from SNF.The longer-term reduction in the SNF application rate is due mainly to a halving of fertilizer rates on grassland.The rate on cropland remained relatively steady until 2022 (EA 2021, 17 (Figure 7)).
The Environment Agency provides a frank assessment of the state of water in England: 55% of England is designated as a Nitrate Vulnerable Zone (NVZ) as its rivers and groundwater breach the safe drinking water limit of 50 mg /l; 69 % of groundwater bodies are at risk of failing to meet Water Framework Directive (WFD) objectives, mainly due to high or rising nitrate concentrations; and, ∼30% of groundwater must now be blended, treated, or replaced to achieve tap safe levels of nitrates.Water treatment is expensive.A nitrate removal plant costs ∼£8m to install and £250,000/year to operate.These costs are passed onto the public in water bills, with a profit margin and return on capital for the utility company.Such costs amount to ∼17% of water bills (POST 2014, 1).Further downstream, 93% of monitored estuarine water bodies and 47% of monitored coastal water bodies in England exceed WFD standards (EA 2018(EA , 2019(EA , 2021)).
Of the total nitrate-N loading, agriculture contributes 69% of the loading in rivers and up to 95% in public water supply catchments.Nitrate concentrations in water draining from agricultural soils exceed 50 mg/l in over 35% of England (EA 2021, 12).Agricultural policies have failed: programmes to reduce agricultural nitrate pollution in NVZs have been in place since the late 1990s but there has been no 'dramatic' long-term reduction in concentrations, and they started rising recently (EA 2019, 3).The Office for Environmental Protection (OEP) found in 2023 that for the goal of 'clean and plentiful water', progress towards five out of six targets 'was either off track, or deadlines had passed and the target not met'; the OEP was unable to assess progress on the sixth target (OEP 2023, 25).These facts, all sourced from UK government agencies with responsibility for enforcing the regulatory regimes governing agriculture, water and air quality, demonstrate the failure of policy and regulation in England and the gap that needs to be filled.

Litigation strategy
Two of the largest international manufacturers of SNF have subsidiaries that manufacture and sell SNF products for use in England.Their scale and long involvement in the English market make these companies potential defendants, although other companies could be considered.
Potential plaintiffs in a negligence case are those whose health or property has suffered physical damage caused by the defendant's products.Whether the defendant owes these classes of plaintiff a duty of care depends on (1) the foreseeability of the damage (2) proximity of relationship between the parties and (3) whether imposing a duty is fair and reasonable.8Categories of plaintiff in negligence could include the following.The first three categories may also have claims in nuisance to the extent that their losses arise from damage to their property or interference with the enjoyment of their property: (a) A person whose health has suffered as a result of poor air quality caused by SNF application; (b) An owner of property that has been damaged by air or water pollution from the application of SNF; (c) A business (e.g., farm, fishing, or marine) that has been damaged by air or water pollution.Water utilities that incur the costs of clean-up themselves fall under this category and may be publicly or privately owned.An analysis of this in the context of plastics pollution has been carried out for the Minderoo Foundation (Beresford et al 2022, paras 109-115); and, (d) A customer of a water company whose water charges have been increased as a result of the cost of removing nitrates, of which SNF is a significant source, from their water supply.
In this case, the plaintiffs are not physically close to the defendant, but the fact that the defendant's product is known to cause these types of injury and damage and has caused physical damage suggests that a duty of care arises. 9No doubt the defendant would argue that the damage is indirect, and that between defendant and plaintiff there are intermediaries such as farmers and distributors.However, it is the defendant who manufactures the SNF, it is the chemistry of the SNF which causes the damage, and the N reaches the plaintiff in the expected form and with the expected effects. 10The chain is understood and predictable, and the results are foreseeable.The fact that the manufacturers are distributing their products to so many customers and over such a wide area (∼70% of England) may impose a duty of care on them rather than relieving them of responsibility for the damage their products cause.In a pattern of diffuse pollution, they are the single-point sources.
Defendants may seek to deny their duty of care by arguing that it is not they but rather farmers who apply the SNF, perhaps contrary to recommended practices.The counterargument is that if the defendant knows that its products are being misused, it is negligent to sell them or to take adequate corrective measures.This is a common contention in tobacco and opioid litigation.The SNF industry seeks, and profits from, higher sales volumes, and evidence would likely show that executives and sales forces are incentivized to maximize sales volumes in spite of the known effects of over-use.In addition, unlike smokers or opioid users (but like passive smokers), the plaintiffs here have no choice or control over their exposure to the effects of SNF and cannot be said to be contributing to the damage.
Other issues that will arise in court include whether licensing of a product provides a defense against an action in negligence, what limitation period applies, and whether any remedy is available other than damages for personal injury and damage to property.In these respects, an action in nuisance could offset the risks.In nuisance the most obvious remedy would be injunction, where there is no need to prove foreseeability. 11

Displacement of the common law by regulation
One argument that is bound to arise is whether private law rights have been displaced by legislation and policy and whether the courts are qualified to consider questions of policy.The New Zealand Court of Appeal recently dismissed a case of negligence and nuisance against major GHG emitters on this basis. 12There are two counterarguments in this case: first, that there is no functional policy regime; and second, that private law remedies for damage to health and property are not displaced.The first argument is the more relevant to this paper.A brief examination of the regulatory regime in England is therefore warranted.
The use of SNF can-and should-be regulated on the basis of its effects on climate change, air quality and water quality, ideally taking an integrated approach (Hicks et al 2022, 162-71).In practice, there is no effective regulatory regime for N or SNF in England-or the United States (Riddle 2020).

Climate change
The UK government does not have a policy to reduce SNF as a source of GHG emissions.The UK's Net Zero Growth Plan (2023) does not refer to SNF or agricultural emissions of nitrous oxide (HMG 2023).The Net Zero Strategy (2021) does not refer to SNF.Instead, it appears to obscure the connection between SNF and GHG emissions by stating that emissions from agriculture mainly stem from 'livestock, agricultural soils, and farm machinery' (HMG 2021, 168). 13The government's Agricultural Transition Plan (2020) also does not mention SNF, but refers to 'nutrient management' and to 'using nutrients and pesticides more effectively' (DEFRA 2020, 33, 41, 52).The more technical GHG emissions report describes 'nitrous oxide emissions related to the use of fertilisers on agricultural soils' (BEIS 2022, 21).
Consequently, while the UK government acknowledges in its technical documentation that SNF causes GHG emissions, its more accessible documents do not mention this.Whether deliberate or accidental, this omission reflects the fact that the UK does not regulate SNF on the basis of its contribution to climate change.

Air quality
There is a gap in the UK regulation of ammonia, with controls applying only to intensive pig and poultry units (via environmental permits) and new agricultural developments (via planning policy) (Hicks et al 2022, 166, 170).None of this affects the application of SNF on existing farmland, or new farmland if such were to be created.As noted above, in the absence of regulation, ammonia emissions have been rising in England and Wales.

Water quality
Water quality regulation is the most developed because of the EU Water Framework and Nitrates Directives.'However, a lack of compliance by farm businesses and inadequate resources for effective enforcement means that this regulation has not been successful in reducing nitrate levels significantly K WWF estimate that [a] given farm can still expect at most a regulatory visit once every fifty years on average K' (Hicks et al 2022, 164).In substance, there is no regulatory regime (Monbiot 2023, 60-64).

Greenwashing
Greenwashing occurs when a company or industry makes false claims about the environmental benefits or negative impacts associated with its business.One of the purposes of greenwashing is to influence policy.Greenwashing cases can be framed in consumer protection law, securities law, company law and potentially in 11 Cambridge Water Co Ltd v Eastern Counties Leather plc [1994] 2 AC 264 [1994] 1 All ER 53 at 69, HL.
12 Smith v Fonterra Co-Operative Group Limited [2021] NZCA 552. 13Emphasis added.constitutional, human rights and common law.Greenwashing cases are being litigated in several jurisdictions with analogies to the SNF situation (Sabin Center for Climate Change Law 2023).This is an evolving area of law that requires further research specific to each jurisdiction.
In addition to the potential for litigation for greenwashing, it is also important to examine the benefits claimed by the SNF manufacturers as they may also be deployed as defenses to other causes of action or to resist injunctive relief.Decades of claims about these benefits have influenced policymakers.The tone of these claims is set up by the slogans of SNF producers: 'Growing a Nature-Positive Food Future' and 'We are proud of our role in helping to feed the world while also protecting the environment'.
Claim 1: SNF is needed to feed the world 'For 75 years, we've produced the agricultural fertilizer farmers need to feed the world.Our core products help to maximize crop yields, providing greater productivity to farmers and overall food security for billions of people.' -SNF producer statement The proposition that SNF feeds the world is widely stated not only by the industry but in the literature, even by scholars who are concerned about the negative effects of the N surplus.A representative example is 'the number of humans supported per hectare of arable land has increased from 1.9 to 4.3 persons between 1908 and 2008.This increase was mainly possible because of Haber-Bosch nitrogen' (Erisman et al 2008).This logic has been extended to suggest that in a (counterfactual) world in which yields had not been improved by the 'green revolution', land use and emissions would have been considerably higher (Burney et al 2010).
In fact, humans consume just 19 million tonnes (8%) of the 227 million tonnes of Nr made available through anthropogenic processes (Hicks et al 2022, 26).The calories and proteins required by today's human population can be produced without SNF, with BFN from leguminous cover crops providing sufficient N (Badgley et al 2007).
Similarly, the estimated world population in 2050 of 9 billion people could be fed organically on the same amount of land as for conventional agriculture, provided that organic farming is part of a well-designed food system (Muller et al 2017).This involves reducing food waste, increasing the share of legumes in farming and diet, and ending the use of arable land to produce animal feed.Animals reared on grassland and food byproducts that would otherwise not be used for human food production would continue to provide 11% of protein in human diets, with the balance provided directly by plants.The resulting diet would have health as well as environmental benefits (Muller et al 2017, 6).
All of these benefits associated with eliminating SNF point to an important principle.Food security implies necessity.It cannot be argued that humans 'need' an unhealthy diet more than they need a healthy one.The same applies in terms of climate and biodiversity, where regulation will soon be needed to curtail excess consumption of meat.This is necessary in order to meet the internationally-agreed goals of the Paris Climate Agreement and the Convention on Biological Diversity-and regulation will be needed to ensure that they are achieved (Weishaupt et al 2020, Stubenrauch et al 2021).
Research also shows that, even if there has been a gap between organic and conventional yields in the past, that is already changing because of deteriorating environment and soil health.Degraded and compacted soils and water stress caused by conventional farming reduce yields such that organic methods improve yields.Organic methods also provide greater resilience as well as mitigating the causes of climate change and environmental degradation (Stubenrauch et al 2021, 718).Hence these authors advocate changes to the EU regulatory regime to facilitate the transition to organic farming.
Potentially better even than organic methods is agroecology.For example, a comprehensive meta-analysis shows that with the agroecologically-grounded System of Rice Intensification (SRI), rice yield per hectare is on average 56% higher than farmer practices and 24% higher than recommended practices (Thakur et al 2023, 3).Some studies show yields doubling and more (Uphoff 2017, 835).Farmers in developing countries obtain consistently high yield ratios when they use intensive agroecological techniques (Badgley et al 2007, 92).These methods can also reduce GHG emissions (Burney et al 2010, 12052, Dahlgreen andParr 2024) and increase carbon sequestration (Das et al 2023).
What then is the basis for Claim 1?The answer is that in today's food system crops and pasture treated with SNF do feed a proportion of the world's population.That is, however, very different from saying that SNF feeds people or is needed.The modern food system is characterized by overproduction and overconsumption as well as waste and inefficiency (Stone 2022b).In terms of health, 'the prevalence of diseases associated with highcalorie, unhealthy diets [is] increasing, with 2.1 billion adults overweight or obese and the global prevalence of diabetes almost doubling in the past 30 years' (Willett et al 2019, 449).This is evidence of a food surplus, not food shortage, as are the numerous initiatives of the past century to dispose of surplus food production (Stone 2022a).If transformation of the food system requires a change in diet, then there are good reasons for that to be a welcome co-benefit, not an objection.
The countries using the most SNF also have the highest food waste.One third of food is wasted globally, with per capita wastage at least 10 times higher in Europe and North America than in sub-Saharan Africa and South/ Southeast Asia (Gustavsson et al 2011, v).There is a 'very close relationship between food surplus and food waste' (Messner et al 2020, 808-9).Overproduction causes (or at least creates the conditions for) both overconsumption and waste.The use of crops to produce animal feed and biofuels is not included in the FAO and other estimates of food waste (Chaboud and Daviron 2017, 1), although these are wasteful uses of N. The correct policy response to prevent food waste and its associated costs would be to address it at source, but industry and government responses focus on managing rather than preventing it (Messner et al 2020).This encourages over-production to continue.
The critical point is that the constraint in food production is fundamentally not a shortage of N for crops.If the supply of food were constrained by the availability of N, then logically humans would not feed maize to cattle.When we eat maize, we consume 42% of the new N provided in its production; when we eat beef only 11% of the new N ends up in our diet (Leach et al 2012, 46).Livestock consume ∼85% of the 14 million tonnes N in crops harvested or imported into the EU; only 15% is used to feed humans directly (Sutton et al 2011).'European nitrogen use is therefore not primarily an issue of food security, but one of luxury consumption' (Sutton et al 2011).
The food surplus has existed since at least 1965; it has grown since then in most OECD countries; and it is expected to increase further to 2050 (Hiç et al 2016).This leads to the conclusion that 'the run-away food production of the last half century has no longer been bound by the purpose of feeding people food to meet their nutritional needs, by market demand or by the necessity to create sufficient safety stocks to secure food availability' (Messner et al 2020, 812).This again illustrates the failure of policy.
Claim 1 (SNF is needed to feed the world) has no foundation in science.Indeed, current methods of farming based on intensive use of SNF are responsible for overproduction, overconsumption, waste and ill-health.Agroecological methods of farming could have continued to feed the world, as they did before the industrial production of SNF began, to this day, and could feed a growing world population.In addition, as we will see below, SNF also undermines food security by contributing to the degradation of soils.Finally, SNF is part of an industrial production system which, by virtue of its centralization, globalization, and standardization, is vulnerable to climate change, new diseases and economic shocks (Foley et al 2011, 341, Monbiot 2023, 27-55).It is not that humanity needs SNF, the need is to eliminate SNF as part of the transition to a safer way of producing the food that humans actually need.
Claim 2: SNF means that agriculture uses less land 'JUST RIGHT application of nitrogen [fertilizer] mitigates climate change and biodiversity loss [=] lower land pressure.'-SNF producer statement 'Proper nutrient application also delivers key environmental benefits, including K reducing pressures related to deforestation.' -SNF producer statement Claim 2 is based on the proposition that SNF increases yield per hectare compared with organic methods of growing crops.There are two main reasons why it does not follow that we use less land for agriculture with SNF than we would without it.
The first reason is that even if SNF can offer a yield benefit, the amount of SNF can be reduced without sacrificing yield in high-input farming systems.As farmers have applied more SNF, efficiency has declined.Between 1961 and 2009 total N input to cropland increased by 4.4x, while cropland protein production increased by 3.1x, implying a reduction of plant N use efficiency from 66% to 46%, and an increase of N losses from croplands from 12 million tonnes to 88 million tonnes (Lassaletta et al 2016, 6).SNF application on maize, wheat and rice alone could be reduced by 28% (11 million tonnes N) without impacting yields (Mueller et al 2012, 255).Further reductions in SNF can be achieved when agroecological methods are added (MacLaren et al 2022).Even simply eliminating SNF would lead to yield reductions that are less than might be expected and small when compared with the potential savings from food waste and dietary change.Eliminating SFN application on wheat and barley would reduce US yields by 16% and 19% respectively while there would be no yield loss for the legumes soybean and peanut (Stewart et al 2005, 2).
The second assumption of Claim 2 is that we use agricultural land to produce the calories and protein we need: if we can improve crop yields, we need (and use) less land.But this logic is not correct: meat and dairy use 83% of farmland worldwide and provide just 18% of calories and 37% of protein (Poore and Nemecek 2018).Land has been converted to agriculture in lockstep with the growing application of SNF, and the main driver has been the increasing production of animals (Alexander et al 2015).If we were to reverse this entirely, and eliminate animals from our diet, we would be able to reduce agricultural land by 76% (Poore and Nemecek 2018, 991).But there is a non-linear opportunity to reduce agricultural land-use through dietary change and less food waste by being more efficient.In the case of beef originating from beef herds, 25% of producers represent 61% of the land use (Poore and Nemecek 2018, 988).
In summary, Claim 2 (SNF means that agriculture uses less land) is incorrect.SNF is largely applied to highly productive cropland to produce animal feed (or biofuels), and as such it is contributing to 'a net drain on the world's potential food supply' rather than being additive to it (Foley et al 2011, 338).SNF has not prevented agriculture occupying more land, but has instead driven development of a food system that is inefficient from a land-use perspective and therefore constantly seeks to expand into the wilderness.
Claim 3: SNF improves soil health and increases carbon sequestration 'JUST RIGHT application of nitrogen [fertilizer] [=] better soil health [and] increased carbon sequestration in soils.' -SNF producer statement 'Proper nutrient application also delivers key environmental benefits, including enhancing soil health K The Coalition of Action 4 Soil Health (CA4SH) projects that healthy soils have the potential to absorb 80 to 100 billion metric tons of carbon between 2020 and 2100, helping to limit global warming and enhance food security.'-SNF producer statement The SNF manufacturers are right to point to the importance of soil health.Nitrogen is largely taken up by plants through soil and therefore declining soil health has grave implications for their own business model as well as for food and fiber production (Mulvaney et al 2009(Mulvaney et al , 2296)).In addition, soil is the largest reservoir of carbon other than the oceans, containing more carbon than all vegetation and the atmosphere combined (Nature Geoscience 2020).The evidence, however, is that SNF does not contribute to soil health, but rather damages it in three ways.
First, SNF does not increase carbon sequestration, i.e. soil organic carbon (SOC).'Among field studies involving synthetic N fertilization and reporting baseline data, the usual finding has been a decrease over time in SOC storage' (Khan et al 2007(Khan et al , 1826)).
Second, SNF depletes soil nitrogen.SNF application 'has often been ineffective for preventing soil N depletion, even in cases involving an ample input of N and the incorporation of crop residues' (Mulvaney et al 2009(Mulvaney et al , 2298)).Also, any N not taken up in the year of application is essentially wasted: the cumulative recovery of N from SNF is only 6.5% over the five seasons after application (Ladha et al 2005, 106).
Third, the physical application of SNF causes compaction of soils.Conventional arable farming involves spraying fields with fertilizers and biocides as well as more overall mechanical activity on the field.The movement of heavy equipment across the fields causes mechanical compaction of soils in addition to the chemical affects described above.Compacted soils reduce the amount of N taken up by plants and this leads to greater denitrification and to losses to groundwater and into the atmosphere (Lipiec and Stępniewski 1995, 48).Soil compaction reduces the uptake of SNF by as much as 100 kg ha −1 ; it also increases N leaching by up to ∼50%; and the N deficiency that it causes in crops leads to more weed growth, and therefore to more herbicide application (Soane and van Ouwerkerk 1995, especially 16-17).Thus, the mechanical application of SNF contributes to a vicious circle of reduced uptake, increased leaching and more SNF application.
In summary, the claim that SNF improves soil health cannot be maintained.
Claim 4: SNF cleans and protects water 'Proper nutrient application also leads to healthier soils and cleaner waterways, protecting our natural resources and preserving forests.' -SNF producer statement As noted, 44% of agricultural land worldwide is in areas where the threshold for N load into surface water is already exceeded by non-agricultural sources, and 17% in areas where other sources already exceed the loading for groundwater.It follows that the application of any SNF in these areas can only make a bad situation worse and therefore could not be described as 'leading to cleaner waterways' or 'protecting water sources'.The 'proper' dose of SNF is zero if the criterion is to avoid further damage, and in any case describing such waterways and other water sources as 'clean' or 'protected' is untenable.
On the balance of agricultural land where non-agricultural sources have not already pushed the nutrient balance beyond planetary boundaries, the application of SNF needs to be sufficiently low that it is not causing any damage to waterways and water sources.Even if an SNF producer could show that none of its products are leaching into local water sources, then it still could not claim to be 'protecting' them or making them 'cleaner'.It would simply not be making them any worse.It is doubtful, however, that a defendant could show zero leaching of its products.
Claim 4 is misleading even if qualified by the concept of 'proper' nutrient application.
Overarching claim: 'climate-smart agriculture' The use of 'proper' and 'just right' to qualify 'nutrient application' itself demonstrates that the SNF industry is aware that its products are not used 'properly' and that there is harm from overuse.The industry's response is to promote 'precision agriculture' while the companies' annual reports reveal plans to increase production and sales.Industry claims in relation to the beneficial effects of 'proper' nutrient application have become the essence of its marketing strategy, its environmental, social and governance (ESG) policies, and its defense against policy interventions to reduce SNF usage.This multifaceted strategy is now gathered under the umbrella concept of 'climate smart agriculture' (CSA), which promotes the idea of a 'triple-win' of (a) climate change mitigation (b) climate change adaptation and (c) food security.Initially put forward by the Food and Agricultural Organization (FAO) (Newell and Taylor 2018, 112), agribusiness companies have become active and enthusiastic participants in CSA, and have sought to define it to serve their own interests.As a result, CSA now prioritizes market and technology solutions over alternative cultivation methods and system change (Clapp et al 2018).CSA promotes approaches such as precision-farming, nutrient-management and 'low-carbon' fertilizer (IFA 2016).This is a flawed, technocentric response whose purpose or effect is to maintain the status quo (Khoury 2023, 318).
First, the focus on GHG emissions caused by the manufacture of SNF ignores the fact that two-thirds of SNF emissions come from their application, not their production (Gao and Cabrera Serrenho 2023, 174).
Second, farmers systematically overapply SNF (Peoples et al 2019, 124-125) and it is very difficult to change farmers' nitrogen-management practices, even when the benefits of nutrient management are recognized and the implementation costs funded (Xia and Yan 2023, 35).This barrier is acknowledged even by advocates of precision agriculture (Gu et al 2023, 80).Such advocates are forced to conclude that 'strong policy interventions are therefore needed to provide an incentive for farmers to adopt advanced nitrogen-management systems' (Xia and Yan 2023, 35).Even in ideal conditions, the SNF industry could rely on inertia to prevent the rapid and widespread adoption of CSA.
Third, however, the policy setting is not conducive to CSA.Perverse subsidies have long encouraged the use of high chemical inputs (Gunningham 1998, 330) and today 87% of farm subsidies actively discourage good environmental practices (FAO, UNDP, and UNEP 2021).These subsidies persist in the face of the damage they cause, and despite growing concerns about their effectiveness (FAO, UNDP, and UNEP 2021, 80, MacLaren et al 2022).
Claims about the benefits of precision agriculture, whether packaged as CSA or otherwise, ignore the realities of farm practices and incentives and are designed to prevent the strong policy interventions that are necessary to bring about change.Regulation of agriculture has always been reluctant and light-touch because of the political influence of the sector.Precision agriculture is a nudge-style approach that proclaims the rationality of farmers while exploiting the bounded rationality of policymakers (Lodge and Wegrich 2016).By casting the responsibility for change onto farmers and consumers the industry deters regulatory action, a strategy widely deployed by industries whose products cause harm (Chater and Loewenstein 2022).
The reasons are obvious: precision application means selling less product, and in a capital-intensive, commodity industry, volume drives margins and profits.The industry recognizes that system and policy change are a threat.One SNF producer discloses in its filings that it faces regulatory risk in the US and internationally from regulations designed to limit 'the use and application of chemical fertilizers due to concerns about the negative impact that the application of these products can have on the environment'.The company states that measures being considered by the UK, Canada, and the EU to impose 'stringent limitations on GHG emissions applicable to farmers, the end-users of our nitrogen fertilizers, could reduce the demand for our fertilizer products to the extent their use of our products increases farm-level emissions'.

Conclusions
The scientific evidence set out above demonstrates the potential viability of private law remedies to address the harm being caused by industrial agriculture and the food system.Private law is, however, no substitute for effective policy and regulation.The more important role of private law may therefore be in the ways in which it can help promote better policy and regulation.These include clarifying the science and impacts of agriculture; promoting the science to the public and media to create a more receptive policy environment; and identifying positive tipping/sensitive intervention points.The forensic process may also clarify the opportunity offered by policy.Agriculture is modular, scalable and can change very fast, yielding benefits within harvest cycles that can be biannual (Stokes 2019).Human needs for healthy food and food security can be met from less agricultural land, with agroecological methods that also improve air and water quality, preserve biodiversity and draw carbon down from the atmosphere.Policy should undertake this transformation, but in the short-term it may fall to private law to do so.In this way, private law is a resource for policymakers.