Michael John Smith (Ngāpuhi, Ngāti Kahu), climate change spokesperson for the Iwi Chairs' Forum, a Māori development platform, filed a case against seven high-emitting New Zealand companies in the agriculture and energy sectors, including the dairy farming conglomerate Fonterra, oil refinery NZ Refining Company, and petrol seller Z Energy. Smith claimed that the defendants' actions constituted public nuisance, negligence, and breach of a duty to cease contributing to climate change.
On March 6, 2020, the High Court of New Zealand rejected the first two claims, but allowed the third to proceed. The court concluded that Smith could not demonstrate public nuisance because the damage claimed was neither particular to him, nor the direct consequence of the defendants' actions. The court further reasoned that showing a public nuisance was difficult given that the defendants are complying with all relevant statutory and regulatory requirements. The court determined that Smith's negligence claim must fail because he had not shown that the defendants owed him a duty of care, concluding that the damage claimed was not reasonably foreseeable or proximately caused by their actions.
The court declined to strike the third cause of action, which alleged that the defendants had a duty to cease contributing to climate change. The court found that there were "significant hurdles" for Smith in persuading the court that this new duty should be recognized, but determined that the relevant issues should be explored at a trial. For instance, the court said perhaps the special damage rule in public nuisance could be modified, and climate science will result in increased ability to model possible effects of emissions. The court warned, however, that it would likely be unable to provide the injunctive relief that Smith seeks, which would require a "bespoke emission reduction scheme."
Following the decision of the lower court, Mr Smith appealed the decisions to strike out the first two causes of action, while the defendants cross-appealed the court's decision that the third cause of action should proceed to trial. On October 21st, 2021, the Court of Appeal dismissed the appeal submitted by Mr Smith and upheld the cross appeal. The court held that tort law was not the appropriate vehicle for dealing with climate change, noting that "every person in New Zealand — indeed, in the world — is (to varying degrees) both responsible for causing the relevant harm, and the victim of that harm." The court held that a determination that the conduct of the respondent companies was unlawful would introduce an "ad hoc" and "arbitrary regime", which would lack democratic legitimacy. The Court of Appeal did, however, note that the courts have some role in climate action: "in holding the government to account".
In late 2021, Mr Smith applied for leave to bring an appeal to the New Zealand Supreme Court. On 31 March 2022, the Supreme Court granted leave to appeal, on the question of whether the Court of Appeal was correct to dismiss the appeal and allow the cross appeal.