High Court

The High Court of New Zealand Auckland Registry dismissed first two claims but not the third. It held that there was no case of public nuisance and no negligence, but potentially a duty to cease contributing to climate damage. Wylie J, giving judgment, stated that 'the defendants’ collective emissions are minuscule in the context of the global greenhouse gas emissions’, that ‘reasonable persons in the shoes of the defendants could not have foreseen the damage claimed by Mr Smith’, and it was ‘an unlikely or distant result of the defendants’ emissions’. This was a matter for legislation, because it "would require the Courts to engage in complex polycentric issues, which are more appropriately left to Parliament" and the "matters are well outside the normal realms of civil litigation."^[2]

92. ‘The most appropriately placed entity in this country to address the complex and collective problems presented by climate change is the Government. Only it can require the necessary collective action by emitters in this country, and action by the defendants alone, whether by Court order or otherwise, will not avoid the damage claimed.’

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102. Mr Smith’s has made no attempt in pleading his third cause of action to refer to recognised legal obligations, nor to incrementally identify a new obligation by analogy to an existing principles. This, I suspect, is because such attempt cannot readily be made. The claimed duty of care is not obviously analogous to any existing duty of care and I doubt that its recognition could be described as a gradual or step by step expansion of negligence liability. The public policy reasons I have identified in [98] above in considering whether a duty of care in negligence can extend in the novel way claimed by Mr Smith, seem to me to create significant hurdles for him in trying to persuade the Court that a new legal duty should be recognised.

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107. The Court would have to consider the extent to which each defendant should be responsible for supply chain emissions for which it is not directly responsible. It would have to guard against double counting between defendants (and entities overseas in the case of BT Mining) and potential future defendants in similar proceedings. The Court would have to select a methodology to apply to carbon dioxide equivalents, so that greenhouse gases could be meaningfully compared when taking into account the different effects of different emissions on global warming...

The Court would have to consider what if any trajectory of net emission reductions each defendant would be required to achieve between 2020 and 2030 (the target date suggested by Mr Smith). The Court would have to determine whether there should be uniform linear progression towards net zero, or whether and how the progression towards net zero should take into account each defendant’s circumstances that might suggest that a particular trajectory would be inappropriate or patently inequitable for one or more of the defendants.

Court of Appeal

The Court of Appeal held that common law requires incremental development, not a radical response. Mr Smith could not identify why the defendants should be singled out. It was accepted none had materially contributed to climate change – and if their contribution were actionable, it would apply to every individual and business: all would have to achieve net zero emissions. It would be a surprising result if every person and business in New Zealand could be brought before the courts for contributing to climate change and therefore restrained from doing so — such a situation would have tremendous social and economic consequences. Additionally, such restraint would have to be enforced and monitored by the courts which would require some sort of emissions offset and trading regime parallel to the statutory regime. Actions would have to be brought on an ad hoc basis which would be inherently inefficient and unjust. Climate change cannot be effectively addressed through tort law. It should only be addressed by the legislature.

According to the court:

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.

Supreme Court

The case was appealed to the NZ Supreme Court.