2. Procedures and Evidence

AUSTRALIA

Corporate climate litigation cases are emerging as a means to hold corporations directly accountable for the impacts of climate change, challenge misleading environmental representations, or drive corporate energy transition and adaptation. [Arguments in these cases explore a wide range of legal grounds, including company and financial law, consumer protection, human rights, and torts. However, the effectiveness and impact of these arguments in these new cases remain uncertain.

Notably, novel arguments [that have been raised and can be raised in litigation against directors for breaches of legal duties regarding climate change are highlighted by the so-called "Hutley opinions" issued in 2016, 2019, and 2021.

CANADA

Plaintiffs in corporate climate litigation [have effectively utilised arguments based on negligence and public nuisance principles. These arguments emphasise the duty of care and the tangible harm caused by corporate defendants due to climate change. While there are challenges related to establishing duty of care, proximity, and causation, public nuisance claims have shown a greater likelihood of success because they do not require as stringent proofs of duty of care and foreseeability. Courts have been receptive to these arguments to varying degrees, with some success in overcoming the traditional barriers of duty of care and causation in specific contexts. In Ryan v Victoria, the Supreme Court of Canada held that defendants may still be liable when the injuries were not "absolutely necessary".

Defendants have primarily argued compliance with existing laws and regulations, shifting responsibility to government bodies for setting and enforcing standards. They also contend that climate change issues are too diffused for attribution to individual corporations and that addressing climate change could adversely affect the economy. Courts have considered these defences alongside public interest considerations, leading to mixed outcomes. In some cases, such as Mathur, courts have rejected arguments that climate change is beyond judicial review, distinguishing it from previous non-justiciable cases because it challenged specific government conduct, namely, the Ontario government's decision to repeal the Climate Change Act rather than a general government policy. However, the Supreme Court's stance in Maple Leaf Foods, emphasising the difficulty of establishing a duty of care for economic losses, could hinder negligence claims, as demonstrated by the Alberta Court of Appeal decision.

For future litigation, plaintiffs might continue to explore and refine arguments around negligence, public nuisance, and especially the public trust doctrine, potentially adjusting strategies based on previous court feedback and evolving legal standards. The challenge will be to effectively link corporate actions directly to climate change impacts and tangible harms, navigating around the Supreme Court's caution against claims for pure economic loss. Additionally, the prospect of applying the public trust doctrine, while not yet successful in Canadian courts as demonstrated by the La Rose case, introduces a novel approach by interpreting government responsibility to protect natural resources for future generations as a basis for initiating claims against corporations considered to be major contributors to climate change.

Defences are likely to evolve, possibly focusing more on demonstrating proactive engagement with climate change mitigation and adaptation strategies, as well as challenging the legal basis for attributing global climate issues to specific entities. Courts will continue to balance the need for legal accountability with the complexities of attributing responsibility for climate change, likely taking into account both the specific legal arguments presented and the broader societal and economic implications of their rulings.

FRANCE

On the merits side, the examination of corporate climate cases remains largely uncharted territory, with many cases not yet reaching this stage. It is uncertain which arguments will prove most compelling in future litigation. Plaintiffs may continue to challenge corporate compliance with duty of care, as in Comissao Pastoral da Terra et Association Notre Affaire à Tous v BNP Paribas, which hinges on the company's adherence to the duty of care outlined in Article L. 225-102-4 of the French Commercial Code, which requires a corporate plan of vigilance for identifying risks and preventing severe human rights violations, serious injuries, environmental damage, or health risks linked to the company's operations. The outcomes of pending appeals and cases yet to begin will provide further insight into effective arguments and defences in French corporate climate litigation.

GERMANY

In past corporate climate litigation, plaintiffs have utilised the argument of imminent violation of legal rights, emphasising that current emissions are causing certain future injuries that do not necessarily need to be imminent but are predictable with certainty. This is based on the Federal Constitutional Court's recognition of the intertemporal dimension of basic rights. However, courts, like the Regional Court of Stuttgart and the Higher Regional Court of Munich, have been sceptical, often finding the effects of defendants' actions on climate change uncertain, thereby not constituting an unlawful infringement of the claimants' rights at present.

Defendants have successfully employed defences related to causation, arguing the difficulty of establishing a direct link between their emissions and specific climate change damages or legal rights violations due to climate change's complex and multifactorial nature. German courts, applying tests like the conditio sine qua non and the doctrine of adequate causation, have generally found it challenging to attribute individual extreme weather events or specific harms to the emissions of a single corporate actor, often dismissing claims on these grounds. For instance, in the RWE case, the court initially denied causality due to the cumulative nature of climate change and emissions from numerous sources.

Future litigation may focus on refining arguments around the partial liability of corporate actors, proportionate to their share of emissions contributing to global warming, as seen in approaches suggested in the literature and partially entertained in the RWE case by the Higher Regional Court of Hamm when it decided to gather evidence on the question of causation and the share of RWE's emissions. This approach aligns with advancing scientific capabilities in event attribution, potentially allowing plaintiffs to establish more concrete links between specific corporate actions and climate change impacts.

On the defence side, corporations might continue to argue the legality of their actions based on compliance with existing permits and emission certificates, positing that their activities are sanctioned by law and do not constitute unlawful behaviour. However, the evolving legal landscape, including the dynamic nature of civil law duties of care, suggests that what is legally permissible now may be viewed differently in the future, especially as the understanding of climate science and its legal implications continue to develop. Courts are likely to grapple with the balance between legal compliance, societal expectations, and the autonomous duties of care that may extend beyond current regulatory frameworks.

INDIA

Plaintiffs in corporate climate litigation in India have deployed a range of arguments, focusing on environmental impact, violation of environmental laws, corporate responsibility, negligence, public nuisance, strict liability, failure to warn, human rights, and proportionate liability. Cases like the Bhopal Gas Tragedy and the Vellore Citizen Welfare Forum have highlighted issues such as the failure to warn residents about hazards, the violation of human rights, and the fundamental right to clean water. Courts have often responded to these arguments by acknowledging corporate activities' significant environmental and human rights impacts, leading to judgments that emphasise the importance of corporate accountability and environmental protection.

Defendants have countered with defences such as lack of causation, compliance with laws and regulations, voluntary measures and best practices, state of the science, statute of limitations, pre-emption, contributory negligence, no duty of care, lack of standing, and acts of God or force majeure. In cases like the Ganga Pollution case, defendants argued that other factors were primarily responsible for the harm. Courts have been critical in evaluating these defences, especially scrutinising compliance with environmental laws and the adequacy of voluntary measures to mitigate environmental impacts.

Future litigation may see plaintiffs refining their arguments to overcome past defences, possibly focusing more on corporate activities' direct and measurable impacts on climate change and environmental degradation. This could include advanced scientific evidence to strengthen causation claims and emphasise the urgency of addressing corporate contributions to climate change. Human rights-based arguments may gain prominence, drawing from international conventions and the Indian Constitution to assert the rights to life, health, and a clean environment.

Defendants are likely to evolve their strategies as well, perhaps by emphasising more sophisticated arguments related to compliance with emerging environmental standards, engaging in sustainable practices, and contributing to climate change mitigation efforts. They may also challenge the applicability of new environmental regulations or argue for more lenient interpretations of existing laws.

Future court responses will depend on the evolving legal and scientific understanding of climate change, with courts possibly showing increased willingness to hold corporations accountable for their environmental impacts while balancing the complexities of economic development and environmental protection.

ITALY

In Italy, plaintiffs have focused on corporate responsibility for climate change, citing human rights violations (notably under Articles 2 and 8 ECHR) and arguing for civil liability under the Italian Civil Code (Articles 2043, 2050, 2051). These arguments leverage "attribution science" to link corporate activities directly to climate change impacts. The Greenpeace and Re: Common v. ENI case exemplifies this approach, though it is noteworthy that many cases have not fully explored these arguments at trial, leaving court responses to these innovative legal theories open-ended.

Defendants, particularly in the ENI case, have argued that their activities, being regulated and authorised, cannot be deemed unlawful or capable of causing unjust damage. ENI also contested the feasibility and legality of imposing drastic reductions in industrial activity on a single company as a means to achieve Net Zero by 2050. Defences have emphasised the challenges in establishing a direct causal link between specific corporate activities and broader climate change effects, arguing against the scientific and legal possibility of pinpointing individual contributions to climate change. Similarly, in the ILVA case, the defence argued that emissions were within legal limits and that the state, not the company, should be held accountable under international agreements like the Paris Agreement. Italian courts have yet to fully address these defences, particularly the argument against direct corporate obligations under international climate law.

Future plaintiff arguments might further refine the use of attribution science and explore new legal theories that better connect corporate activities with specific climate change impacts, possibly drawing from successful international precedents like the Dutch Shell case. However, the Italian legal context poses challenges, as in defence arguments stressing the lack of binding national legal foundations for principles established by international soft law instruments. Defendants are likely to continue challenging the scientific basis of attribution, the justiciability of climate actions against individual companies, and the applicability of international climate obligations to private entities within Italy. Courts' responses may evolve as the scientific understanding of climate change attribution becomes more precise and as societal expectations for corporate accountability in climate change mitigation increase. Future litigation might also test the extent to which Italian courts are willing to integrate international climate law principles into domestic corporate liability cases.

JAPAN

Plaintiffs have primarily argued that the risk to their health and safety from climate change represents an imminent danger, warranting injunctions against corporations whose activities significantly contribute to global warming. For instance, in the Mito District Court decision of 18 March 2021, an injunction was granted against the operation of a nuclear power plant.

On the defence side, companies have effectively argued that the causal link between their specific emissions and global climate damages is too weak, emphasising the global and diffused contributions to climate change. Moreover, the defendants have maintained that their operations, such as running coal-fired power plants, are legally sanctioned and serve the public good, aligning with national energy plans. Courts have often been receptive to these defences, weighing their decisions' broader policy and economic implications.

Potential strategies in litigation may involve plaintiffs refining their approach to demonstrate a more direct and immediate threat to their rights, possibly by leveraging advancements in attribution science. This addresses the courts' scepticism toward establishing a direct causal link between corporate emissions and immediate harm to individuals, attributing this to the complex, global nature of climate change. For example, the Kobe District Court's decision reflected doubts about the concrete risk of infringement on plaintiffs' rights to life, body, and health, pointing to the global scale of emissions and the uncertainties involved. Moreover, there is an emerging focus on the right to live in a stable and healthy environment, which offers a more tangible connection to climate change impacts. Additionally, future litigation might challenge the legality of high-emission activities more vigorously, arguing that continuing such operations is incompatible with human rights and environmental sustainability, especially in light of international climate targets and scientific evidence.

KENYA

In past Kenyan corporate climate litigation, effective plaintiff arguments have centred on establishing the responsibility of corporations for environmental harm and human rights violations through the logic of attribution science, connecting corporate activities directly to climate change impacts. The Kenyan Constitution and Climate Change Act have facilitated this by delinking causation from locus standi in public interest litigation, allowing for broader admission of claims even without individualised loss, provided there is a generalisable injury attributable to the defendant. However, proving causation — the connection between the defendant's actions and the resulting harm — remains a critical factor in assessing the validity of legal claims. Yet, Kenyan courts have not fully adjudicated on this matter. They are encouraged to take into account advances in attribution science when evaluating the impacts and damages caused by climate change.

Defendants have successfully employed the defence of mootness, arguing that the court cannot provide a remedy for the claims presented, either due to the impossibility of redress or because of supervening events that render the issue moot (e.g., the relief sought by a claimant against becomes unavailable). The Kenyan High Court's stance, as seen in Evans Kidero v. Speaker of Nairobi City County Assembly & Another, underscores the importance of judicial economy and the necessity for claims to present a justiciable controversy with practical value for adjudication.

Future litigation may see plaintiffs leveraging advancements in the science of attribution to establish a more direct link between corporate actions and climate change impacts. This approach could help overcome challenges related to proving causation and redressability by providing empirical evidence of a corporation's contribution to climate change. However, distinguishing between event attribution and legal causation will be crucial. Defendants might counter by challenging the applicability or interpretation of scientific evidence in legal frameworks. Taking cues from international jurisdictions like the Philippines, Kenyan courts may become more receptive to integrating attribution science into legal causation assessments, potentially paving the way for more nuanced and scientifically informed adjudication of climate change impacts and damages.

NETHERLANDS

Plaintiffs in corporate climate litigation have effectively argued for the responsibility of companies to mitigate their greenhouse gas emissions, underlining the imminent violation of legal rights due to climate change. These arguments often draw on landmark rulings, such as the Urgenda and Shell cases, which established the concept of partial responsibility for climate harm based on national tort and human rights law. Courts have generally responded by recognising that even if an individual entity's emissions are small, they cannot evade responsibility merely because their contribution to global emissions is minor. This acknowledges the collective impact of emissions and the role of individual actors in contributing to climate change.

Defendants have employed several defences challenging the effectiveness and appropriateness of litigation to address climate change. They argue that their emissions are too small to be deemed dangerous, that unilateral emission reductions would be ineffective ("drop in the ocean" argument), and that other parties' failure to reduce emissions renders any single company's efforts inconsequential. Courts have critically examined these defences, particularly emphasising that each actor has a part to play in mitigating climate change, regardless of the actions of others. The Shell case highlighted that companies cannot claim immunity based on the potential for others to fill the emissions gap they leave behind, underlining each emitter's partial responsibility to the global climate effort.

Future plaintiff arguments could focus on enhancing the application of national tort law to climate litigation, emphasising corporations' autonomous (yet partial) responsibility to reduce emissions and the direct impact of their actions on climate change. Such arguments could further exploit scientific advancements in event attribution, providing more precise links between specific corporate activities and climate-related harm.

On the other hand, defendants might continue to argue the legality of their actions based on compliance with emissions permits and certificates, suggesting that their conduct is sanctioned and regulated by existing laws. They may also point to the societal benefits of their activities as a defence against claims for emission reductions. However, as seen in the Shell case, courts may increasingly require companies to align their operations with broader climate goals, even beyond the minimum standards set by law, acknowledging the evolving nature of societal expectations and legal standards around environmental protection and corporate responsibility.

NIGERIA

Plaintiffs in corporate climate litigation have made significant strides, particularly in challenging traditional barriers to court access, such as the defence's commonly raised argument of lack of standing.

Defendant corporations have employed a range of defences, including misjoinders of parties and causes of action, lack of pre-action notice, lack of standing to sue, inadequate scientific evidence establishing causation, contravention of the statute of limitations, and questions of the court's subject-matter or territorial jurisdiction. These defences, often grounded in legislation, have historically posed significant hurdles to corporate climate actions due to strict interpretations by the courts

NORWAY

In Norwegian corporate climate litigation, plaintiffs have used constitutional and international human rights arguments to challenge industrial developments with varied success. In Greenpeace Nordic Ass'n v. Ministry of Petroleum and Energy (People v Arctic Oil), the argument based on §112 of the Norwegian Constitution aimed to establish an individual right to a healthy environment against oil drilling licenses. The court recognised §112 as a rights provision but ruled that the government's environmental impact assessments prior to licensing were sufficient, indicating a high bar for proving direct violation of §112 in future cases. Conversely, in Statnett SF et al. v. Sør-Fosen siida et al., the claim that windfarm development violated the Sami people's rights under Article 27 of the ICCPR was upheld by the Supreme Court, highlighting the protection of indigenous practices (in this case, traditional reindeer husbandry) from industrial threats.

Future plaintiffs may further explore constitutional and international human rights provisions, emphasising the interconnectedness of environmental protection, cultural survival, and climate change mitigation. They could focus on demonstrating the broader impacts of corporate and governmental actions on the environment and cultural practices, drawing from international principles and domestic constitutional rights.

Foreseeing the courts' sensitivity to environmental and cultural impacts, defendants might strengthen their defences by showcasing more rigorous environmental impact assessments, compliance with environmental laws, and the broader benefits of their projects. They could also emphasise the consultations and involvement of affected communities in the planning processes to mitigate adverse impacts.

Courts will likely continue to navigate the delicate balance between environmental conservation, cultural preservation, and economic development. The evolving legal landscape suggests that both plaintiffs and defendants will need to adapt their strategies to address the complex interplay of legal, environmental, and social considerations in corporate climate litigation.

PHILIPPINES

Plaintiffs in corporate climate litigation have found success by focusing on arguments that demonstrate the violation of environmental laws through scientific evidence and the direct causation of environmental harm. As such, in Segovia, the Supreme Court did not issue environmental writs due to a lack of concrete evidence of wrongdoing and the adverse impacts of pollution on health. The decision also considered the [efforts made by respondents to comply with environmental regulations]11.

Defendants have utilised several defences effectively, including mootness, where harmful activities ceased or negotiations were entered, as in the Arigo case. Additionally, arguments around the lack of violation of environmental laws, due diligence, and force majeure have been employed, with mixed court responses.12 For instance, in the Rayo case, the Supreme Court rejected the National Power Corporation's (NPC) [defence of force majeure due to proven negligence13]. This decision underscored that mere claims of due diligence or unforeseen events are insufficient without tangible evidence of precautionary measures to prevent harm. [Furthermore, it highlighted that acts of God do not exempt parties from liability if human factors, such as negligence, contributed to the harm.] On the other hand, the Supreme Court's handling of the "Road Sharing Principle" in Segovia as a non-binding principle underscores the court's recognition of discretion in the implementation of environmental policies.

Future litigation is likely to see plaintiffs refining their arguments to more clearly demonstrate violations of environmental laws and the causal links between corporate actions and environmental damage. Emphasising health impacts and utilising scientific evidence will be key. On the defence side, corporations may focus on demonstrating compliance with environmental regulations and the implementation of harm mitigation measures. Courts will continue to weigh legal compliance, policy discretion, and the evidence presented in these cases, with a notable preference for resolutions that facilitate rehabilitation and compensation for environmental damage, signalling a shift towards judicial support for negotiated settlements and proactive environmental stewardship.

POLAND

Polish courts have historically recognised the challenges plaintiffs face in proving specific causation in environmental pollution cases. Since a Supreme Court ruling in 1976,[10] plaintiffs have been relieved of the burden to prove that their health damages were specifically caused by pollutants from a defendant's facilities, acknowledging the impracticality of such a requirement. This approach effectively lowers the evidentiary burden on plaintiffs, offering a form of prima facie evidence in cases of harm from environmental pollution.

In recent litigation concerning air quality in Poland against the State Treasury, plaintiffs alleging health damages due to smog and non-compliance with air quality standards have been required by at least one court to demonstrate a causal link between their health deterioration and the polluted air. According to the court, the causal link could be substantiated by medical evidence of diseases linked to smog exposure. In another notable case, the Warsaw court ruled in favour of the plaintiff, emphasising the direct impact of polluted air on health, and referencing Poland's inadequate implementation of EU air quality directives.[11]

Defendants, including the State Treasury, have attempted to invoke the political question doctrine, arguing that climate change mitigation and adaptation fall under the purview of the executive and legislative branches and are not suitable for judicial resolution. However, Polish courts have dismissed this defence, choosing to adjudicate on the matters presented.

In defence, companies have initially denied the anthropogenic causes of climate change, disputing the impact of human activities on global warming and even suggesting the beneficial effects of increased atmospheric CO2. Yet, such defences have been largely abandoned or deemphasised as the litigation progresses. For example, PGE shifted its defence to minimise its own contributions to greenhouse gas emissions as insignificant, arguing against the effectiveness of the remedy sought by plaintiffs.

The evolution of environmental litigation in Poland suggests a trajectory towards more sophisticated arguments concerning the responsibilities of both state and corporate actors in mitigating environmental harm. Plaintiffs may continue to leverage scientific evidence and EU regulatory frameworks to strengthen their cases while also emphasising the direct health impacts of environmental degradation. Future litigation may further explore the responsibilities of corporations in contributing to climate change, challenging the adequacy of existing regulatory frameworks and corporate practices.

Defendants are likely to refine their strategies, potentially moving away from outright denial of climate change to arguments focused on compliance with existing regulations, contributions relative to broader industry or global emissions, and the economic or national security implications of environmental litigation.

Polish courts' responses indicate a growing acknowledgment of the judiciary's role in environmental matters, potentially paving the way for more assertive rulings that recognize the health and environmental impacts of pollution and climate change, even as they navigate the complex interplay of science, law, and policy.

[10] Judgment of the Supreme Court of 7 October 1976, IV CR 380/76.
[11] District Court in Warsaw, VI C 1043/18, 24 January 2019.

UNITED KINGDOM

Plaintiffs in the UK have encountered challenges in establishing standing in corporate climate cases, as seen in McGaughey and ClientEarth v. Shell. The argument that claimants lack standing to bring certain actions has been a significant barrier, often accompanied by procedural tactics employed by defendants to delay proceedings. However, other broad arguments include questioning the justiciability of claims, where defendants argue that matters of climate change are best left to the legislature or political processes. This approach has seen varying degrees of success; for example, in Milieudefensie v. Shell in the Netherlands, the court rejected the defendant's assertion that the energy transition should be left to legislative efforts, demonstrating a willingness to adjudicate on corporate responsibilities for climate change.

Defendants have successfully utilised arguments about the admissibility of claims and the claimants' lack of standing, employing procedural delays as a strategy. Arguments that climate litigation encroaches on political territory or is not justiciable have been presented, reflecting a belief in the separation of powers. Such defences align with a broader judicial philosophy in the UK that emphasises political accountability for climate change. However, the effectiveness of these arguments varies, with courts sometimes rejecting the notion that litigation should be avoided because the issue is politically charged, as indicated by the proactive stance in Milieudefensie v Shell.

Looking ahead, the rapidly evolving science connecting corporations to climate change and specific emissions to certain events may challenge defendants' strategies of using delay tactics. Arguments that a defendant's emissions are negligible on a global scale or that market substitution would negate the impact of halting a particular project have been met with scepticism. UK courts have shown a reluctance to quantitatively assess high-emitting projects against carbon budgets, as seen in cases like the one against Drax Power Limited. Another potential defence is compliance with existing legislation or regulations, though this is risky given the discrepancy between the UK's climate ambitions and detailed regulatory frameworks.

UNITED STATES

In the first wave of climate litigation, plaintiffs faced challenges in moving beyond the argument that climate change issues represented a political question beyond judicial review, as seen in AEP v. Connecticut. However, in cases like Barasich v. Columbia Gulf Transmission, plaintiffs succeeded when seeking monetary damages instead of injunctions, overcoming the political question barrier.

As the litigation progressed, plaintiffs began to confront jurisdictional manoeuvres by defendants aiming to shift cases from state to federal courts, often under the guise of the cases being political questions or by invoking "federal officer removal statutes," which authorises any officer (or any person acting under that officer) move to federal court a civil action commenced in state court when the claims are for or relating to any act under colour of such office. Despite these efforts largely serving to delay proceedings, such as in the City of New York case, they have so far not succeeded in derailing cases entirely.

Public nuisance claims have seen plaintiffs grappling with the application of the balancing test, which weighs the "unreasonableness" of the defendant's actions against the plaintiff's use and enjoyment of land. The challenge here lies in overcoming the argument that using fossil fuels, a widespread societal norm from which plaintiffs also benefit, does not constitute an "unlawful invasion."

Defendants have effectively delayed the progression of cases through strategic jurisdictional challenges, albeit with limited success in dismissing cases based on the merits. The invocation of the political question doctrine and federal officer removal statutes highlights the defensive strategy aimed at avoiding liability by emphasising the political and widespread nature of climate change responsibility.

The use of the balancing test in public nuisance claims serves as a robust defence, challenging the plaintiffs to prove the "unreasonableness" of activities that are deeply integrated into societal and economic structures. The reasoning in the City of New York case exemplifies courts' reluctance to deem the defendants' actions as unreasonable given the plaintiffs' concurrent use of fossil fuels.

Looking forward, plaintiffs might refine their strategies to navigate around the imminence and standing defences more successfully. The cases against Shell Oil and those in Connecticut and Rhode Island demonstrate a path forward by focusing on near-term impacts of climate change to satisfy the imminence requirement for standing. By emphasising immediate and foreseeable harms, plaintiffs can overcome the hurdles posed by the need to demonstrate a direct and imminent threat.

On the other hand, defendants may continue to refine their jurisdictional and political question defences while also exploring new arguments that could leverage the systemic nature of climate change and the societal reliance on fossil fuels. The balancing test, highlighting the societal benefits of fossil fuels, remains a potent defence in public nuisance claims.