IN THE HIGH COURTOF NEW ZEALAND
I TE KŌTI MATUA O AOTEAROA
TE WHANGANUI-Ā-TARA ROHE
 NZHC 733
UNDER the Judicature Amendment Act1972and Part 30 of the High Court Rules
IN THE MATTER OF decisions made under the Climate Change Response Act 2002 and public decisions made in relation to the United Nations Framework Convention on Climate Change
BETWEEN SARAH THOMSON
AND THE MINISTER FOR CLIMATE CHANGE ISSUES
 This is a judicial review proceeding concerning the Government’s response to climate change. It is brought by the plaintiff who is a law student concerned at that response and the consequences of its alleged inadequacy on future generations.
 It is common ground that climate change presents significant risks and that serious and prompt global action is required if dangerous consequences for the planet and its inhabitants are to be prevented.
 For example, Professor Hansen,who is a leading expert in climate change and who has filed affidavit evidence for the plaintiff, says:
We will not preserve a habitable climate system unless developed nations act without further delay, both to phase out their own emissions and to aid the balance of nations in the development of their own carbon free energy sources.
 Similarly, the Hon TimothyGroser, the Minister for Climate Change Issues over the relevant period, who has filed anaffidavit on behalf the defendant, says:
Tackling climate change is crucial if we are to avoid harm to people, the environment and the economy. As Minister, I accepted the global scientific consensus on climate change as set out in the [AR5]. It is not in doubt that climate change is a global issue that needs to be addressed seriously and promptly by all states if global warming is to be kept at less than 2ºC. An increase of more than 2ºC would be dangerous.
 Judicial review is concerned with the lawful exercise of statutory or public powers. It provides a constitutional check on public power exercised by the Executive branch of government, but it has limits reflecting the separation of powers between the Courts and the Executive. There is a difference in view between the parties in this case about whether the Government’s response to climate change, as challenged in this proceeding, is amenable to review by the Court and if so,on what basis.
 This judicial review challenges two decisions made by the Minister for Climate Change Issues. Each concerns a target for reducing harmful greenhouse gas emissions. One of those, the 2050 target, was set under domestic legislation. It is accepted this is amenable to review but the parties differ on whether the Minister breached that legislation by not reviewing the target following updated international scientific consensus about climate change.
 The other decision concerns the setting of a 2030 target pursuant to an international agreement (the Paris Agreement). The defendant considers this decision falls to be determined in international rather than domestic fora. The defendant further considers the 2030 target is a policy decision which involves balancing competing considerations and is outside the Court’s proper role. The plaintiff considers the decisions are amenable to review on traditional judicial review grounds.
 On the first cause of action (relating to the 2050 target) I accept that, following the release of the AR5, the Minister was required to turn her mind to whether there had been any material change as between the AR4 and the AR5 that was relevant to the 2050 gazetted target,and that this did not occur. However this cause of action has been overtaken by subsequent events. The new Government has announced it intendsto set a new 2050 target. Court ordered relief is therefore unnecessary.
 On the second and third causes of action (relating to the NDC decision which set a 2030 target) I am not persuaded the Minister made any reviewable error for which the Court may intervene. The international framework has been followed. It has not been demonstrated the NDC decision was outside the Minister’s power under this framework. That is not to say another Minister would have assessed the appropriate 2030 target in the same way and reached the same decision. Nor does it prevent New Zealand from doing more between now and 2030 than contemplated in its NDC decision. The international process envisages review and demonstrated progression by developed countries including New Zealand. Quite apart from the international process, New Zealand remains free to review its 2030 target (or any other target) as it considers appropriate. The community has elected a new Government and it is for that new Government to weigh the competing factors and to reach a view about the appropriate targets going forward.
 For these reasons the application for judicial review is dismissed.
 My preliminary view is that the costs should lie where they fall. If there is any issue about thisthe parties may submit brief memoranda (no more than five pages each and limited to the issues in dispute) within three weeks of the date of this judgment.
Full judgment: Thomson v Minister for Climate Change Issues [PDF]