Smith v Fonterra: New Zealand’s Supreme Court Climate Case

Smith v Fonterra is a New Zealand climate change lawsuit in which Māori elder Mike Smith is suing seven of the country’s largest greenhouse gas emitters, arguing their emissions amount to public nuisance, negligence, and a proposed new tort of climate system damage. In February 2024, the Supreme Court of New Zealand unanimously ruled that all three claims could proceed to trial, reversing lower courts that had struck the case out.¹ A 15-week trial is scheduled to begin in the High Court in April 2027, but in May 2026 the New Zealand government announced legislation to bar climate tort claims before the trial can be heard.²

Who Mike Smith Is and What He Wants

Mike Smith is a 67-year-old kaumatua (elder) of Ngāpuhi and Ngāti Kahu descent and a veteran climate activist who attended the 1992 Rio Earth Summit and led campaigns against offshore oil exploration between 2010 and 2018. He co-chairs the climate directorate of the National Iwi Chairs Forum.³

Smith is not seeking damages. He wants a court declaration that the defendants have acted unlawfully and an injunction requiring them to peak emissions by 2025, cut them significantly by 2030 and 2040, and reach net zero by 2050. His claim is grounded in kaitiakitanga, or guardianship: he argues the defendants’ emissions are damaging his ancestral coastal land and waters at Mahinepua in the Far North, and threatening resources he is culturally and legally obligated to protect.⁴

The Seven Defendants

Smith sued seven companies that together account for roughly a third of New Zealand’s greenhouse gas emissions, each occupying a different point in the fossil fuel and agricultural supply chain:⁵

Fonterra Co-operative Group, New Zealand’s dominant dairy company, which operates eight coal-burning factories
Genesis Energy, operator of the country’s largest thermal power station
Dairy Holdings, operator of 59 dairy farms
New Zealand Steel, operator of the country’s largest steel mill
Z Energy, a major fuel retailer
Channel Infrastructure NZ, operator of the country’s largest fuel import terminal, which handles 40% of national fuel supply and 80% of jet fuel
BT Mining, owner of the country’s largest opencast coal mine

All seven participate in New Zealand’s Emissions Trading Scheme and operate within statutory requirements. The Supreme Court was clear that regulatory compliance does not immunize a company from tort liability.¹

The Three Claims

Smith pleaded three causes of action. The first is public nuisance, based on the argument that emissions from the defendants are harming public rights, including his access to and use of coastal land and waters. The second is negligence, resting on the defendants’ knowledge of their emissions and the foreseeability of climate harm. The third is a proposed new tort Smith calls climate system damage, framed as a freestanding duty to cease materially contributing to climate change.⁶

Smith filed his claim in the High Court at Auckland in 2019. In March 2020, Justice Wylie struck out the nuisance and negligence claims but allowed the proposed climate duty to proceed. In October 2021, the Court of Appeal struck out all three, describing climate change as a “polycentric issue” unsuitable for judicial resolution.⁷ Smith appealed to the Supreme Court.

Why the Supreme Court Let the Case Proceed

On 7 February 2024, the Supreme Court unanimously reinstated all three causes of action and sent the case back to the High Court for trial. Chief Justice Winkelmann and Justices Glazebrook, Ellen France, Williams, and Kós all joined the opinion.¹

On public nuisance, the Court held that emissions did not need to be independently illegal to constitute a nuisance and rejected the view that causation across many emitters was a fatal barrier at the pleading stage. It compared the situation to 19th-century cases involving multiple factories discharging into the same waterway, and said those complexities required evidence and policy analysis at trial rather than summary dismissal.⁸ On the “special damage” rule required for standing in public nuisance, the Court expressed doubt about whether it should survive at all, and found it at least arguable that Smith met it through his legal and tikanga-based interests in the Mahinepua coast.⁹

The negligence claim was reinstated because it rested on overlapping facts with the nuisance claim. The proposed climate system damage tort survived on the reasoning that common law is capable of evolving and that a trial was the appropriate venue for that evolution. The Court wrote that “the common law must develop, if at all, in the fertile fields of trial, not on the barren rocks of a strike out application.”⁸

The defendants had argued that the Climate Change Response Act 2002 and the Resource Management Act 1991 created a comprehensive regime that displaced tort law. The Court rejected this, pointing to section 23 of the RMA, which states that compliance with the Act “does not remove the need to comply with all other applicable legislation and other rules of law,” and noting that the Climate Change Response Act contains no provision excluding concurrent tort liability.¹⁰

The Court also affirmed that tikanga Māori, the customary law and values of Māori society, has been cognizable at common law since 1840 and should inform the reach and content of Smith’s claims. Tikanga concepts of loss, including harm to whakapapa (genealogical connections to the land), whanaungatanga (relational obligations), and kaitiakitanga (guardianship of natural resources), could bear on standing, special damage, and the framing of duties. The Court left the details to be worked out at trial.¹¹

Pre-Trial Rulings in the High Court

Since the case returned to the High Court, the defendants have filed a series of interlocutory applications, and Justice Andrew has ruled on the major ones. On 16 April 2025, the Court refused a request by the first to third defendants to join an unlimited number of overseas entities, including foreign governments and corporations, as third parties, finding that joinder would introduce complexity, expense, and delay and would very likely push back the April 2027 trial date.⁷ The Court also rejected an attempt by the first to fifth defendants to have the case declared a “universal representative proceeding” in which they would stand in for all major New Zealand emitters, treating it as an effort to relitigate a question the Supreme Court had already settled.¹²

On 17 June 2025, the Court declined BT Mining’s request to have preliminary questions heard before trial and its application for $150,000 in security for costs. Smith’s own applications to split the trial into separate liability and remedy phases and to obtain protective costs orders were also declined, with room left to revisit those issues later.⁷

The Government’s Move to Block the Case

On 12 May 2026, Justice Minister Paul Goldsmith announced that the government would amend the Climate Change Response Act 2002 to “prevent findings of liability for tort for climate change damage or harm caused by greenhouse gas emissions in both current and future proceedings.” The announcement explicitly referenced the Smith v Fonterra litigation. Goldsmith said climate change management is a national responsibility that should not be handled through “piecemeal litigation” and that the amendment would give businesses legal clarity and certainty.²

Smith called the proposal “an outrageous abuse of parliamentary power and a direct attack on the rule of law.” Green Party co-leader Chlöe Swarbrick described it as “shady cookery.” Greenpeace Aotearoa spokesperson Gen Toop said “ministers should not be rewriting the law to shut down cases they don’t like.”¹³

Lawyers for Climate Action NZ, the Environmental Law Initiative, and Smith himself lodged a formal complaint with the United Nations Special Rapporteur on human rights and climate change, arguing the proposed law would violate the right of access to courts, minority rights under the International Covenant on Civil and Political Rights, and climate due diligence obligations articulated in the International Court of Justice’s July 2025 advisory opinion. The complaint noted that government officials had internally advised that there was “no evidence the ongoing litigation has had a measurable impact on business confidence” and that “the constitutional and access-to-justice costs outweigh any certainty a bar might provide.”¹⁴

An analysis in the European Journal of International Law argued the proposal may also violate non-regression environmental clauses in New Zealand’s trade agreements with the European Union, the United Kingdom, and CPTPP partners.¹⁵ As of mid-2026, the bill had been announced but legislative text had not yet been introduced.²

Where the Case Stands Now

The 15-week substantive trial remains scheduled to begin in April 2027 in the High Court of New Zealand.⁷ Whether it proceeds turns largely on whether the tort immunity legislation is enacted first. The bill had not been introduced by mid-2026, and critics have pointed to the limited time in the current parliamentary term before the next general election. Fonterra separately announced in August 2025 that it had agreed to sell its consumer businesses to Lactalis, a deal expected to close in the first half of 2026 and to prompt the company to reassess its emissions reduction targets.¹⁶

The case sits within a broader global pattern. New Zealand ranks eighth worldwide for cumulative climate litigation, with 38 cases filed and seven currently active, and Smith v Fonterra is the only corporate-focused climate framework case among them.¹⁷ Legal scholars describe it as a “next-generation” case that shifts the focus from challenging government policy to holding private corporations directly liable in tort for their contributions to climate harm.⁵ Parallel developments are unfolding elsewhere: the U.S. Supreme Court granted certiorari in February 2026 in Suncor Energy v. County Commissioners of Boulder County to decide whether federal law preempts state-law climate tort claims,¹⁸ and Utah enacted the first U.S. “climate liability shield” law in April 2026, with similar bills introduced in Louisiana, Tennessee, and Congress.¹⁹

1
Courts of New Zealand. Smith v Fonterra Co-Operative Group Limited, NZSC 5
2
New Zealand Government (Beehive). Government Brings Certainty Climate Change Tort Law
3
The Guardian. Mike Smith Maori Climate Activist Right to Sue Companies
4
E-Tangata. Michael Versus the Goliaths
5
Elgar Online. Smith v Fonterra – Chapter 4
6
Australian Environmental Law. Smith v Fonterra
7
Sabin Center for Climate Change Law. Smith v Fonterra Co-Operative Group Limited
8
Columbia Law School Climate Change Blog. Smith v Fonterra: A Common Law Climate Litigation Breakthrough
9
Franks Ogilvie. Smith v Fonterra Co-Operative Group Ltd 2024 NZSC 5
10
Human Rights Law Centre. Smith v Fonterra
11
LSE Law Review Blog. Two Worlds Collide: Exploring the Role and Significance of Tikanga Maori in Smith v Fonterra
12
Climate Policy Radar. Smith v Fonterra Co-Operative Group Ltd, NZHC 940
13
ICLG. New Zealand Moves to Block Climate Lawsuits Ahead of Landmark Trial
14
Lawyers for Climate Action NZ. Taking the Tort Prohibition to the UN
15
EJIL: Talk!. Denial of Environmental Justice: Would a Bar on Climate Tort Litigation Be Inconsistent with New Zealand’s International Obligations
16
Fonterra. Reporting
17
Chapman Tripp. Climate Litigation in New Zealand
18
SCOTUSblog. Supreme Court Agrees to Hear Case on Colorado Dispute Over Climate Change
19
NPGA. Utah Enacts Climate Shield Law