Climate Tort Law and the Rise of Climate Accountability Cases

Climate tort law refers to the use of civil liability principles—such as negligence, nuisance, and duty of care—to hold major greenhouse gas emitters legally responsible for the harms caused by climate change. Rather than challenging government policy or regulatory decisions, climate tort cases focus on the conduct of private actors, particularly fossil fuel producers and large industrial emitters, and ask whether they can be held liable for contributing to climate-related damage.

At its core, climate tort law asks a simple but powerful question:

If a party knowingly contributes to foreseeable harm, should it be legally responsible for the consequences?

This approach adapts long-established principles of tort law to the modern reality of climate science.

Climate tort claims typically draw on several well-established legal doctrines:

• Negligence – alleging that a defendant owed a duty of care, breached that duty, and caused foreseeable harm.
• Public nuisance – arguing that large-scale emissions interfere with public rights such as health, safety, and environmental integrity.
• Private nuisance – where climate impacts interfere with the use or enjoyment of land.
• Duty of care – asserting that corporations whose activities pose systemic risks owe obligations to avoid causing harm.
• Foreseeability – relying on decades of climate science showing that the impacts of greenhouse gas emissions were well known.

Climate plaintiffs argue that these principles are not new; what is new is the scale and cumulative nature of the harm.

Climate change presents a challenge for legal systems because harm is:

• Cumulative rather than isolated
• Global but locally experienced
• Caused by multiple actors over time

Climate tort law responds by focusing on contribution rather than sole causation. Courts are increasingly asked to consider whether defendants made a material contribution to harm, even if they were not the only cause.

This shift mirrors earlier legal developments in cases involving:

• Tobacco companies
• Asbestos manufacturers
• Lead paint producers
• Environmental contamination

In each case, courts eventually recognised liability where corporations:

1. Knew their products caused harm
2. Continued harmful conduct
3. Profited from that conduct
4. Shifted costs onto the public

Around the world, courts are being asked to grapple with climate responsibility:

• United States – State and municipal governments have brought nuisance and deception claims against fossil fuel companies.
• Europe – Courts have recognised duties of care requiring emissions reductions and climate risk mitigation.
• Global South – Communities are increasingly seeking redress for climate-induced loss and damage.

While outcomes vary, a key trend is emerging: courts are becoming more willing to hear climate tort claims rather than dismissing them as "non-justiciable" political questions.

Smith v Fonterra Co-operative Group Ltd and others is a landmark case in Aotearoa New Zealand and internationally.

The case is brought by Mike Smith (Ngāpuhi, Ngāti Kahu), who alleges that major corporate emitters—including fossil fuel and industrial companies—have negligently contributed to climate change, causing harm to land, ecosystems, and Māori cultural interests.

What makes Smith v Fonterra significant is not a claim for compensation, but a claim for injunctive relief—seeking court-ordered limits on emissions to prevent further harm.

Key legal features of the case include:

• Reliance on tort law, not statutory climate regulation
• Arguments grounded in foreseeability and duty of care
• Recognition of Māori relationships with whenua, moana, and taonga
• An assertion that courts have a legitimate role in addressing climate harm when regulatory systems fail

In 2023, New Zealand's Supreme Court allowed the case to proceed, rejecting arguments that climate tort claims are inherently political or unmanageable. This decision marked a global first at the highest appellate level.

The Court held that:

• Novelty alone is not a reason to strike out a claim
• Common law can evolve in response to new forms of harm
• The scale of climate change does not automatically place it beyond judicial consideration

The significance of Smith v Fonterra extends well beyond New Zealand:

• It affirms that courts can hear climate tort claims
• It opens the door for community-led climate accountability
• It challenges the assumption that only governments bear responsibility for climate action
• It integrates Indigenous legal perspectives into climate jurisprudence

The case is closely watched by legal scholars, climate advocates, and courts worldwide as a potential turning point in climate accountability.

Climate tort law is still emerging, but its trajectory is clear. As climate impacts intensify and regulatory responses lag, courts are increasingly being asked to fill accountability gaps.

Key questions for the future include:

• How courts define duty of care in a climate-altered world
• How responsibility is apportioned among multiple contributors
• How Indigenous rights and knowledge shape climate jurisprudence
• Whether injunctions, not just damages, become a primary remedy

Climate tort law does not replace political action—but it reshapes the legal landscape by affirming that those who cause harm cannot remain beyond accountability.