Constitutional lawyer Mai Chen says the Government’s move to legislate against common law climate change tort claims is “not unlawful”.
But Lawyers for Climate Action acting executive director Laura MacKay said legislating retrospectively and intervening in a live case would be “highly unusual” and “contrary to the basic principles of the rule of law and the separation of powers”.
The comments follow Justice Minister Paul Goldsmith’s announcement on May 12 that the Climate Change Response Act 2002 will be amended to block tort claims for climate change damage.
Goldsmith said the proposed amendment would apply to current and future cases, effectively preventing the landmark Smith v Fonterra case from proceeding to trial.
The Government argues the amendment would “remove the possible development of a new regime that contradicts the framework Parliament has already enacted to respond to climate change”, referring to measures including the emissions trading scheme.
The case
But MacKay disagreed, saying New Zealand’s climate change legislation and emissions trading scheme “do not allocate responsibility for who should pay for damage caused by climate change, and do not preclude a role for the common law”.
She argued that it was not unusual for courts to develop common law in response to major new challenges, pointing to the development of nuisance law during the Industrial Revolution’s pollution crisis.
MacKay said individuals should generally have their cases heard based on the law in force at the time proceedings were brought.
University of Otago law professor Nicola Wheen went further, describing judicial independence as a core constitutional principle that “enables courts to ensure the executive acts lawfully and individuals are protected from exercises of arbitrary power.
“If governments can interfere with courts, this protection is broken down. It doesn’t matter what law is being developed; governments should not interfere with court proceedings.”
MacKay also cautioned the proposal “sets a precedent that the law can be changed retrospectively if the Government of the day doesn’t like what the courts say” and “risks weakening our constitutional arrangements and the rule of law”.
She drew “strong parallels” with the Foreshore and Seabed Act 2004, which retrospectively extinguished Māori customary title claims following a Court of Appeal decision that partly recognised those rights.
She also pointed to Parliament’s 2025 amendments to the Marine and Coastal Area Act, which reversed aspects of a 2024 Supreme Court ruling.
She described Parliament intervening after Supreme Court decisions as “a worrying trend, particularly under the current Government”.
When asked about the implications for other tort-based climate claims, MacKay said the Government’s announcement “may halt Smith v Fonterra, but it does not remove the underlying questions, particularly of the effectiveness of New Zealand’s existing climate laws.
“Rather, it removes one way they were being tested.”
Chen said: “Parliament is able to legislate to stop live court proceedings. It is not unlawful.”
She said a judicial review seeking to stop the Government from introducing the bill was unlikely to succeed.
If the legislation passes, opponents could seek a declaration of inconsistency under the NZ Bill of Rights Act, though Chen cautioned that “a successful declaration does not overturn the enactment”.
She noted that the Government had already declined to act on two previous declarations regarding the voting age and prisoner voting rights.
Smith v Fonterra
Iwi leader Mike Smith is suing seven of NZ's largest greenhouse gas emitters – including Fonterra, Genesis Energy and NZ Steel – arguing their emissions damage the climate system and threaten his land and way of life.
The case was struck out by the Court of Appeal in a unanimous 2021 decision, which concluded tort law was not an appropriate vehicle for addressing climate change.
But the Supreme Court unanimously overturned that ruling in February 2024, finding the claims were at least arguable and that Smith should "get his day in court".
The Supreme Court allowed Smith’s claims in negligence, public nuisance and a proposed “climate system damage” tort to proceed to trial.
MacKay said “the Supreme Court was clear that tort law should have the opportunity to evolve to address issues of climate change”, noting the court said public nuisance principles should not “stand still in the face of massive environmental challenges attributable to human economic activity”.
She said the Supreme Court decision had already become a landmark precedent internationally, and climate litigation in NZ would continue through other avenues.