Māori climate activist Mike Smith celebrates big win in legal battle against some of New Zealand's biggest polluters

Māori activist Mike Smith is celebrating a big win in his legal battle against some of the country's biggest polluters.  

The Ngāpuhi and Ngāti Kahu elder has been fighting for years against what he calls the "polluting 7" - including Fonterra, Z Energy and Genesis.  

Now, the Supreme Court has ruled his case can go to trial - a decision few were expecting. 

"This court has unanimously allowed Mr Smith's appeal and reinstated his statement of claim," Justice Stephen Kos said. 

That gives Smith the right to sue seven of New Zealand's biggest companies for contributing to climate change. 

"Mr Smith's claim should be allowed to go to trial rather than being struck out pre-emptively," Justice Kos said. 

Smith was convicted in 1994 for trying to chop down the lone pine on One Tree Hill in an act of protest over Treaty of Waitangi rights. 

These days, he's the one using the law to stop what he sees as wrongdoing. 

"As you'd expect, we're... excited and grateful," Smith said of Wednesday's ruling. 

He's grateful because the case had earlier been thrown out by the Court of Appeal on the basis there was no reasonable argument that could be made. 

"The Supreme Court has found in our favour so obviously there is merit in the argument, so we look forward to getting the top seven polluters in court," Smith said. 

Together, they create about a third of New Zealand's carbon emissions. 

A leading law professor said the Supreme Court decision was a surprise. 

"Very few people would've thought they would win this case when they filed it back in 2019," said Victoria University's Geoff McLay. "I myself said they had absolutely no chance of winning this case." 

Greenpeace said it puts other polluters on notice. 

"It means that big climate polluters in Aotearoa now know that they may be taken to court and will have to justify whether they cause harm or not," Greenpeace NZ executive director Russel Norman said. 

Fonterra, Genesis Energy and Z Energy declined Newshub's interview requests but issued statements expressing their disappointment in the ruling.  

They all argue they're committed to meeting their climate change obligations and are making good progress.  

Smith, meanwhile, is vowing to keep up his fight until the companies are forced to reduce or cease their emissions.  

"I guess the... aim is to save our mokopuna, because it's not abstract anymore climate change - we are feeling it every day." 

The case is now expected to go to the High Court for a full hearing.