New Zealand’s Climate Lawsuit: Supreme Court Win and Proposed Ban

The New Zealand climate lawsuit known as Smith v Fonterra is a tort case brought by a Māori elder against seven of the country’s largest greenhouse gas emitters. In February 2024, the Supreme Court unanimously ruled it could go to trial, the first time a common law court has allowed a full climate tort trial against private companies. A fifteen-week hearing is scheduled to begin in April 2027 — if the government’s proposed legislation to block such claims does not extinguish the case first.

Who Is Suing and What They Want

Michael John Smith is an elder of Ngāpuhi and Ngāti Kahu and a climate change spokesperson for the Iwi Chairs Forum. He acts as a kaitiaki, or guardian, for the environment in the Mahinepua area of Northland. His claim is that the defendants’ greenhouse gas emissions have damaged his whenua (land) and moana (ocean) in places of “customary, cultural, historical, nutritional and spiritual significance” to him and his family.¹

Smith pleads three causes of action: public nuisance, negligence, and a novel tort he calls “climate system damage” — a duty not to materially contribute to dangerous interference with the climate system through greenhouse gas emissions.² He is not asking for money. He is asking for declarations that the defendants breached their duties, and for injunctions requiring them to reach net-zero emissions by 2050, with interim reduction targets along the way.³

The defendants span dairy, energy, steel, fuel, and mining, and together account for roughly one-third of New Zealand’s greenhouse gas emissions.⁴⁵⁶

What the Supreme Court Ruled

The case moved through three levels of the judiciary. The High Court in 2020 struck out the nuisance and negligence claims but let the climate system damage tort survive. The Court of Appeal in 2021 struck out all three, holding that climate change was a matter for regulators and Parliament, not judges.²

On February 7, 2024, a five-judge Supreme Court panel unanimously reversed the Court of Appeal and reinstated all three causes of action. The claims were not “bound to fail” and deserved to be tested at trial rather than dismissed at the preliminary stage.²

Several parts of the ruling matter for how the trial will unfold. On whether New Zealand’s Climate Change Response Act 2002 blocks tort claims, the Court said it does not: the statute neither “permits” emissions nor creates a “right to emit,” and participation in the Emissions Trading Scheme does not immunize a company from liability.²

On causation — the problem that any one company’s emissions mix with those of millions of other sources worldwide — the Court likened the difficulty to historical pollution cases involving multiple contributors to contaminated air or water. Climate change was a “quantum leap scale of enlargement” of familiar problems, and whether an individual defendant’s contribution was substantial enough to matter required evidence rather than assumption.³

On public nuisance, the Court confirmed the underlying activity does not need to be illegal under a statute to count as a nuisance. It also accepted that Smith’s position as a Māori landowner and kaitiaki plausibly satisfied the “special damage” requirement for standing, a question to be evaluated through tikanga Māori, meaning Māori customary law and values.³

The Road to a 2027 Trial

Back in the High Court, the defendants tried to slow the case by applying to join an unlimited number of overseas emitters as third parties. In April 2025, Justice Andrew rejected the application, finding it would generate “complexity, expense and delay” inconsistent with the High Court Rules’ goal of just and speedy resolution, with a “very high likelihood” of derailing the trial date.⁷ The fifteen-week substantive trial is now scheduled to begin in April 2027.⁵

The Proposed Law to Kill the Case

On May 12, 2026, Justice Minister Paul Goldsmith announced that the government would amend the Climate Change Response Act 2002 to stop courts from holding companies liable in tort for climate change damage caused by greenhouse gas emissions. The amendment is written to apply to both current and future proceedings, which would reach Smith’s case directly.⁸

Goldsmith said “the courts are not the right place to resolve claims of harm from climate change” and that tort law is “not well-suited to respond to a problem like climate change which involves a range of complex environmental, economic and social factors.” He framed the change as a response to “uncertainty in business confidence and investment” and said climate policy belongs in Parliament, the Emissions Trading Scheme, and existing legislation.⁹ The government has said the amendment would not alter its own obligations under climate legislation or companies’ duties under the ETS.⁸

Reporting has since shown that the six remaining defendants met with government ministers in 2024 and provided a “briefing note” pushing for the amendment, citing “material sovereign risk” and uncertainty for international investors. The defendants disclosed those documents the same day the government announced the proposed law change.¹⁰ Fonterra has publicly welcomed the proposal.¹¹

As of mid-2026, no bill has been introduced. The Ministry for the Environment says the government “intends to introduce a bill to the House in 2026,” but the legislation has not been assigned a bill number, has not had a first reading, and has not been referred to a select committee.¹² The government has signaled it wants to pass the law before the general election in November 2026.⁹

Opposition to the Proposed Ban

The announcement drew immediate criticism from lawyers, academics, and environmental groups.

More than 100 international lawyers and climate researchers, organized by Lawyers for Climate Action, wrote an open letter to Prime Minister Christopher Luxon and Minister Goldsmith calling the proposal “contrary to New Zealand’s climate objectives,” saying it “blocks the development of the common law” and “risks undermining the rule of law” by shielding a small number of companies at the expense of the public interest.¹³

Greenpeace Aotearoa called the move a “shocking abuse of executive power.” Gen Toop of Greenpeace said: “The courts exist to hold powerful interests to account and protect the public interest. Ministers should not be rewriting the law to shut down cases they don’t like.”¹⁴ The Environmental Defence Society called the proposal an “attack on the rule of law.”⁹ Victoria University of Wellington scholars Bjørn-Oliver Magsig and Graeme Austin wrote that “courts do things governments cannot. They cannot be lobbied. They decide on evidence and law.”

Legal scholars have also raised international law objections. Oliver Hailes of the London School of Economics argued that extinguishing a pending tort claim breaches the right of access to court under the International Covenant on Civil and Political Rights, citing the UN Human Rights Committee’s view that legislatively discontinuing pending cases would be “objectionable.” Critics also cite non-regression clauses in the EU-NZ FTA, the UK-NZ FTA, and the CPTPP, which prohibit weakening environmental protections to encourage trade or investment. Because the government’s stated purpose is to provide certainty for business investment, scholars argue the amendment fits the conduct those clauses are designed to prevent. The July 2025 ICJ advisory opinion on state climate obligations, confirming binding due diligence duties on states to mitigate emissions and regulate private actors, has been cited as further evidence that dismantling domestic judicial mechanisms runs counter to international law.¹⁵

Where Things Stand

The Smith v Fonterra trial is set for April 2027. Whether it actually opens depends on the amendment. Because New Zealand’s constitutional system allows parliamentary supremacy without judicial review of legislation for constitutionality, the government could in principle end the case by statute.¹⁵ Smith has said that if the legislation passes he will challenge it immediately under the New Zealand Bill of Rights Act 1990 and access-to-justice principles, and will contest the retrospective extinguishment of his claims.¹⁰ If the amendment does not pass, the trial proceeds against six of the country’s biggest emitters on three tort theories that a unanimous Supreme Court has already said deserve to be heard.

1
The Guardian. Mike Smith: Māori Climate Activist Wins Right to Sue Companies
2
Courts of New Zealand. Smith v Fonterra Co-Operative Group Limited, 2024 NZSC 5
3
Columbia Law School Sabin Center. Smith v Fonterra: A Common Law Climate Litigation Breakthrough
4
The Spinoff. The Missing Climate Briefing Email Has Been Found
5
Climate Case Chart. Smith v Fonterra Co-Operative Group Limited
6
LawNews NZ. Government Blocks Climate Change Lawsuits Against Big Emitters
7
Australian Environmental Law. Smith v Fonterra Co-Operative Group Ltd
8
Reuters. New Zealand Plans Law Change to Stop Private Climate Lawsuits
9
Down to Earth. New Zealand Moves to Protect Companies From Private Climate Lawsuits
10
The Wave. New Zealand Bowed to Lobbyists to Maim Climate Litigation
11
Fonterra. Fonterra’s Case for Legislative Change to Climate Change Response Act
12
Ministry for the Environment. Amending the Climate Change Response Act
13
E&E News. Lawyers Urge New Zealand to Ditch Plan to Ban Climate Lawsuits
14
Inside Climate News. New Zealand Amends Climate Law to Protect Polluters
15
EJIL Talk. Denial of Environmental Justice: Would a Bar on Climate Tort Litigation Be Inconsistent With New Zealand’s International Obligations