1. Government Powers to Address Climate Change

1.1 Federalism

The Constitution embodies a model of political constitutionalism in rights review. As we noted, this means that government is largely held accountable through ‘the common law and political processes’,^[1] alongside some judicially enforceable guarantees. There are two key consequences that flow from this model for our purposes. First, the Constitution is designed to facilitate effective governance.^[2] It empowers representative Parliaments with the capacity to enact laws on a broad range of matters and holds that governments will ultimately be accountable to the people for the policies and laws that they pursue. Second, as a corollary, there is little in the Constitution that can be used to compel government to act. This may cause challenges when some people believe government is moving too slowly in the face of the climate crisis.

This does not mean there are no legal limits on what governments can do. The Constitution preserved the already established colonies of New South Wales, Queensland, South Australia, Tasmania, Victoria and Western Australia. It transformed these colonies into ‘states’ and created a new national tier of government known as the ‘Commonwealth’. The Constitution’s enactment in 1901 saw the states and Commonwealth begin governing Australia collectively (with the British Parliament retaining its ability to oversee this governance well into the 20th century). This power-sharing model of government is known as ‘federalism’. In part 1, we outline how governmental responsibilities regarding climate change are divided between the Commonwealth and states. As we will see, some of the most significant High Court decisions in the environmental field are actually conflicts over federalism: that is, whether the Constitution allows the Commonwealth or states to enact laws in that space.

1.2 State Powers

The Constitution grants the states ‘plenary power’, meaning that they have a general power to make laws on whichever topics they wish (subject to certain limitations in the Constitution, discussed in part 2).^[3] The states may therefore legislate freely on environmental and climate protection. An example of this is Victoria’s Climate Change Act 2017, which establishes the state’s long-term emissions reduction target of net zero by 2050.

In the event of inconsistency between a state law and Commonwealth law, section 109 of the Constitution holds that the state law will be invalid to the extent of the inconsistency. Inconsistency includes, inter alia, situations in which the Commonwealth might choose to ‘cover the field’ of climate mitigation through a comprehensive legislative regime. State laws which also address climate mitigation would then be invalid.

1.3 Commonwealth Powers

While the states can legislate on almost any topic that they choose, the Commonwealth can only legislate on certain topics permitted by the Constitution. These topics are known as ‘heads of power’, most of which are listed in section 51. Notably, none of these heads of power refer directly to the environment. There are two reasons for this. First, the states were granted plenary power because they, as colonies, pre-existed the Commonwealth. The framers wanted the states to continue governing most aspects of societal life. Their view was that the Commonwealth should only be responsible for a specific list of topics that were national in character.

Second, in the 1890s, environmental matters were seen as ‘local’ issues and, thus, better left to the states.^[4] Awareness of the environment as a complex, interconnected set of ecosystems only emerged around the 1970s. It was in this period, as concerns over pollution and other large-scale ecological challenges developed, that the Commonwealth took more of an interest in environmental matters.^[5] It passed its first environmental protection legislation in 1974, the Environment Protection (Impact of Proposals) Act.

To pass such legislation, the Commonwealth needed to fit its laws within existing heads of power (again, none of which directly relate to the environment). This caused tensions between the Commonwealth and states (among others), particularly in the 1970s and 1980s.^[6] In a series of cases, the High Court was called upon to clarify whether various heads of power were expansive enough to cover environmental policy areas. These cases proved to be some of the most significant in the High Court’s history, altering the trajectory of Australian constitutional jurisprudence.

In the 1983 Tasmanian Dam Case, the Commonwealth passed environmental protection legislation to stop Tasmania damming the Franklin River, which is situated within a World Heritage site.^[7] The Commonwealth argued that the external affairs power in section 51(xxix) permitted it to pass laws on external matters, including implementing international treaty obligations, even if it did not possess a head of power on the subject matter of the treaty. A narrow majority of the Court agreed, concluding that the Commonwealth legislation protecting this World Heritage site aligned with the UNESCO Convention for the Protection of the World Cultural and Natural Heritage 1972. In reaching this decision, the High Court was careful to explain that it was ‘in no way concerned with the question whether it is desirable or undesirable … that the construction of the dam should proceed’. Rather, it answered the ‘strictly legal question’ about the scope of Commonwealth power.^[8]

The external affairs power could similarly be used to pass legislation ratifying climate treaties, such as the 2015 Paris Agreement. However, the Commonwealth can only draw upon the external affairs power to implement a treaty if certain conditions are met. One such condition is that the Commonwealth law must be reasonably appropriate and adapted to achieve the relevant treaty obligations.^[9] Such obligations also need to have sufficient specificity. As noted in the Industrial Relations Act Case, vague, aspirational statements will not activate the external affairs power.^[10] This may be of concern if the climate treaty in question is drawn in terms that are too ambiguous.

The High Court has generally taken a broad view when interpreting heads of power. This provides the Commonwealth with ample opportunity to legislate on environmental and climate matters.^[11] In Murphyores v Commonwealth, for instance, the Commonwealth drew upon the trade and commerce power in section 51(i) to protect the ecologically fragile K’gari (Fraser Island).^[12] Commonwealth regulations required an environmental assessment be conducted on mining practices on the island before export approval of the minerals could be granted. The Court upheld the validity of this law. This was because, as long as the law was sufficiently connected to this head of power’s subject matter (interstate or international trade and commerce), it was irrelevant that it ‘touches or affects a topic on which the Commonwealth has no power to legislate’, namely, environmental protection.^[13]

Thus, even though no head of power directly refers to environmental management, the Commonwealth has substantial power to legislate on climate matters. A range of heads of power beyond those discussed above are relevant in this regard. The taxation power in section 51(ii), for example, may support carbon tax legislation. Similarly, the corporations power in section 51(xx) may support Commonwealth laws requiring trading corporations to restrict their fossil fuel production or use.

Other avenues can also be considered. For instance, the Commonwealth’s fiscal dominance allows it to influence state policies. This primarily occurs through section 96, which enables the Commonwealth to offer grants to the states with conditions attached. These conditions often require that the states carry out aspects of the Commonwealth’s policy agenda — again, even concerning matters where the Commonwealth does not have legislative power.^[14] The states are susceptible to such offers, given the country’s ‘vertical fiscal imbalance’. This is the term used to describe the reality in modern Australia that the Commonwealth enjoys far more lucrative tax revenue streams (and less spending responsibilities) than the states, leaving the Commonwealth with substantial bargaining power. Thus, the Commonwealth could offer tied grants to the states, requiring them to undertake significant climate mitigation and adaptation strategies.

A more consensual approach would be to rely on section 51(xxxvii). This provision allows the states to refer policy areas to the Commonwealth where it does not have the head of power needed. While the Commonwealth and states have disagreed on environmental matters over the years, in contemporary times both are generally committed to a cooperative federalist approach in which they work together.^[15] As Peter Johnston concludes, the Constitution has proven ‘remarkably adaptable’ in extending federalist arrangements to environmental issues.^[16]

What if, however, people believe that neither the states nor the Commonwealth are willing to use their powers to take necessary climate action — or are using their powers to accelerate climate change? This is where constitutional limitations on government power, or the lack thereof, become relevant.