Vanderstock & Anor v The State of Victoria

The High Court of Australia heard an appeal concerning the constitutional validity of Victoria's *Climate Change Act 2022* (Vic). The appellants, Ms Vanderstock and Mr. Wilson, challenged the Act, arguing it was invalid under section 109 of the *Constitution* due to inconsistency with Commonwealth legislation, specifically the *National Greenhouse and Energy Reporting Act 2007* (Cth) and the *Climate Change Act 2022* (Cth). The core of the dispute revolved around whether the Victorian Act's provisions mandating greenhouse gas emission reduction targets and related obligations imposed an impermissible burden on the Commonwealth's legislative power.

The central legal question before the High Court was whether the Victorian *Climate Change Act 2022* was invalid by reason of inconsistency with Commonwealth legislation, pursuant to section 109 of the *Constitution*. This required the Court to determine if the Victorian Act's provisions, which set binding greenhouse gas emission reduction targets and imposed obligations on various entities to achieve these targets, were so inconsistent with the Commonwealth's legislative scheme for regulating greenhouse gas emissions that they could not operate concurrently. The Court had to consider the scope and purpose of both the Commonwealth and Victorian legislation to ascertain if a legal inconsistency existed.

The High Court, in a majority decision, found that the Victorian *Climate Change Act 2022* was not invalid under section 109 of the *Constitution*. The majority reasoned that the Victorian Act and the Commonwealth legislation operated in distinct spheres and did not create a direct inconsistency. While both pieces of legislation dealt with greenhouse gas emissions, the Victorian Act established state-level targets and obligations that were complementary to, rather than in conflict with, the Commonwealth's national reporting and regulatory framework. The Court applied the principles of constitutional interpretation concerning implied prohibitions on state legislation that would substantially impair the exercise of a federal power, finding that the Victorian Act did not reach this threshold. The Court emphasised that the Victorian Act did not prevent the Commonwealth from exercising its legislative powers, nor did it impose obligations that were irreconcilable with Commonwealth law.

The appeal was dismissed, and the *Climate Change Act 2022* (Vic) was held to be valid.