The Supreme Court has agreed to hear a case against some of New Zealand's biggest polluters in what some describe as judicial activism

The world is watching for the outcome of a unique climate change case in front of our Supreme Court that will expose the actions - or lack of them - of our biggest polluters

The bosses of several of our biggest polluting companies will soon be under the microscope when they take the stand in the High Court and reveal what they are doing about their carbon footprints.

"This is one of the most significant climate change cases that New Zealand has ever experienced," says Auckland University associate law professor Vernon Rive, an expert in climate change law. "We're all on the edge of our seat."

Seven companies - Fonterra, Z Energy, Genesis, Dairy Holdings, NZ Steel, Channel Infrastructure and BT Mining - are being taken to the High Court by Northland leader Mike Smith, of Ngāpuhi and Ngāti Kahu, over their greenhouse gas emissions.

It follows a landmark unanimous decision earlier this month by the Supreme Court that Smith had the right to sue the seven, going against previous decisions by the High Court and the Court of Appeal.

The decision surprised many in the sector.

"Until the Supreme Court's decision the general thinking was that you couldn't bring a court claim against another person for their greenhouse gas emissions," says Blair Keown, who is a partner at Bell Gully which is involved in the case. "If you did it would be struck out before going to trial."

Keown says the case is the first of its kind in the world and it is being closely watched here and overseas.

"The Supreme Court has opened a door that was pretty firmly closed and some may see opportunities arising out of that. That could involve the bringing of similar claims, it could involve testing the boundaries of other legal principles.

"But against that some could wait to see how the Smith case develops before deciding whether to bring a claim of their own because climate change-related cases are complex, they're challenging, they're potentially time consuming and so there's arguably a case for waiting to see how that develops before deciding whether or not to bring an action of one's own."

Many of the country's largest law firms are representing the seven corporates at the High Court trial, which Smith hopes will start this year, given what he sees as the urgency of the matter. …

Go to this episode on rnz.co.nz for more details