The Supreme Court reinstated Smith’s case, after it was earlier thrown out by the Court of Appeal on the basis there was no reasonable basis for argument.
The climate activist, of Ngāpuhi and Ngāti Kahu, says the group, including Fonterra, Z Energy and Genesis Energy (which together make around a third of New Zealand’s emissions), have a legal duty to him and others in communities who are being damaged by planet-heating gases.
He wants them to either stop polluting, or start bringing emissions down quickly.
An important feature of the case is the role of tikanga Māori, and how it determines Smith’s relationship to coastal land and waters that are being flooded and damaged.
The Supreme Court noted it was not ruling on whether the case had a good chance of succeeding, only that “Mr Smith now gets his day in court”.
Genesis Energy said in a statement it was “disappointed”, and that the case would divert resources from actually cutting emissions by building up renewable energy.
Lawyers for the big emitters had argued in court that damage from climate change affected everyone, and was best tackled by laws and Parliament, not by the courts using common law.
But the Supreme Court ruled that “while the effects of human-caused climate change are ubiquitous and grave for humanity”, they affected people to different degrees.
It ruled that just because Parliament had laws for addressing climate change, did not stop Smith bringing a case.
The case is one of several internationally using the courts to try to speed up action on the crisis.
The Court of Appeal had earlier ruled the crisis was so big and all-encompassing it should be dealt with at the national and international government level, but the country’s highest court disagreed.
The Supreme Court’s ruling on Wednesday noted it was common ground at the hearing that the window for securing a livable and sustainable future for all people was closing.
It cited the Intergovernmental Panel on Climate Change’s findings that “as the planet continues to warm, climate change risks ‘will become increasingly complex and more difficult to manage’”, and, “the probability of ‘abrupt and/or irreversible changes’ increases with higher global warming levels”.
The case will now go back to the lower courts for a full hearing, with expert evidence.