‘Climate Overloading’ and Separation of Powers Arguments: Reflections on Pabai v Commonwealth of Australia
25.09.2025
The recent Federal Court decision of Pabai v Commonwealth (No 2) [2025] FCA 796 considered whether the Commonwealth owed two duties of care to the Torres Strait Islander people with respect to particular harms connected with climate change. The Court rejected the plaintiffs’ claims. The decision is relevant on a number of fronts, including its findings regarding causation and that the cultural loss and harm experienced by the plaintiffs — fulfilment of Ailan Kastom — was not a legally recognisable ‘head of damage’ that can be compensated. However, in this post I focus on a particular feature of the Court’s analysis: the finding that the Commonwealth owed neither duty of care because decisions connected with the two argued duties involved matters of ‘core policy’.
Australian courts, and common law courts elsewhere, have questioned the concept of ‘core policy’ and the distinction between ‘policy’ and ‘operational’ decisions upon which the concept is based. The Federal Court in Pabai — like the Full Court in Minister for the Environment v Sharma [2022] FCAFC 35 — nonetheless relied upon characterising the duties as involving matters of ‘core policy’ as a basis for rejecting findings that a duty existed. I argue that in both cases the Court sought to use the concept of ‘core policy’ as a vehicle to express abstract concerns about its institutional role and separation of powers. But as a vehicle to express those abstract concerns, it is a concept that lacks stable doctrinal application. Courts have noted the impossibility of defining it and questioned its utility. Its logic is both conclusory and categorical, which sits uncomfortably with the common law method of reasoning. The basis for declaring a decision a matter of ‘core policy’ lacks clear guiding principles that allow for further development through argument before future courts. All this risks producing unpredictable results in claims against public authorities in the future. This issue is particularly likely to affect claims regarding climate harms, especially if the concept is so load-bearing in the reasoning in these cases.
In this post, I connect the reliance on the concept of ‘core policy’ in Pabai and Sharma with the phenomenon of ‘climate overloading’. I describe ‘climate overloading’ as an argumentation strategy that takes a more context-specific, discrete question that could be susceptible to a legal answer and lumps that question together with the problem of climate change as whole. By framing the questions before the court at such a high level of abstraction and complexity, defendants effectively ‘overload’ the questions before the court so that they are not susceptible to concrete legal analysis. Defendants can then leverage separation of powers concerns, leading the court to reject the plaintiff’s claim.
Duties of care on public authorities and matters of ‘core policy’
Under Australian common law, plaintiffs must establish that their negligence claims either fall within an established category of duty or can analogise to an established duty. To establish this latter ‘novel’ kind of duty, plaintiffs must prove that someone in the position of the defendant could foresee the kind of harm that the plaintiff experienced, and that there was a special kind of relationship between the defendant and plaintiff that has certain characteristics. These characteristics — called ‘salient features’ — include among other things the vulnerability of the plaintiff to the particular harm, the control of the defendant over the risk of harm, the defendant’s assumption of responsibility to prevent the harm, and the coherence of the posited duty with other areas of law.
Common law duties of care may be imposed on public authorities. For example, in Crimmins v Stevedoring Finance Committee (1999) 2001 CLR 1, the High Court found that a statutory authority owed a duty of care to a worker who contracted mesothelioma when exposed to asbestos on a worksite. The High Court found that the statutory authority owed the worker a duty of care when directing the worker to places of work. Similarly, in Electricity Networks Corporation v Herridge (2022) 276 CLR 271, the High Court found that a statutory authority owed a duty of care to a class of people for loss and damage from a bushfire that started because of the electricity network the authority operated. This was because the statutory authority ‘stepped into the arena’ by placing its equipment at the site of the fire, creating a relationship between it and all that was within the vicinity of the electricity system that caused the fire.
When determining whether to impose a duty of care on a public authority in the exercise of its functions, courts have sometimes considered whether the duty would involve ‘policy’ decisions as opposed to ‘operational’ decisions. This distinction has created much angst for Australian tort law teachers, precisely because it resists definition. As the Federal Court in Pabai noted (at [112]), the distinction is extremely difficult — if not impossible — to delineate and its usefulness has been questioned in courts and scholarship in the United Kingdom, Australia and Canada. The Federal Court in Pabai noted that the distinction is not a firm one, but rather ‘expressive’ of a more elusive concept that has appeared in various forms in the case law — it encompasses decisions that involve ‘core area[s] of policymaking’ or ‘policy-making powers and functions of a “quasi legislative character”’ (at [117]). Some courts in England and Australia have sought to pin the difference down by describing ‘policy’ decisions as those having implications for budgets or the allocation of resources. This approach is also fraught. Almost every decision by a public authority, as noted in Pabai, affects its budget ‘in either timing or amount’ (at [113]), rendering the distinction unstable.
The reason for the policy / operational distinction is practical, rather than normative. Decisions involving ‘policy’ are left to the parliament and executive not to empower the franchise, but because of a lack of stable legal standards against which the government’s conduct can be measured (see [121]). In Pabai, the Court noted that ‘the issue comes down to whether the reasonableness of the government conduct in issue can properly be gauged by the court’ (at [122]). Notably, Australia lacks a ‘political question’ doctrine where contentious matters should be left to elected branches.
Pabai and parallels and differences to Sharma
Wadhuam Pabai Pabai and Wadhuam Paul Kabai live on two particularly low lying islands, Boigu and Saibai, in the Torres Strait. They are leaders of the Guda Maluyligal nation, part of the Torres Strait Islander people that are a distinct indigenous group in Australia. Torres Strait Islander identity and traditional practices, called Ailan Kastom, are deeply interconnected with the lands and waters where they live.
The Torres Strait Islands are uniquely exposed to the impacts of climate change, with some islands highly likely to be uninhabitable less than 25 years from now. Coastal inundation and flooding are destroying infrastructure, cultural sites and freshwater and food sources. Australia’s contribution to global greenhouse gas emissions is extremely significant for its size. Its domestic territorial emissions are some of the highest in the world per capita and it is the one of the largest exporters in the world, responsible for 4.5% of global emissions once exports are counted.
The plaintiffs brought proceedings against the Australian federal government on behalf of Torres Strait Islander peoples arguing that the Commonwealth owed them two common law duties of care. They argued one duty of care required the government to take into account the best available science when setting nationally determined contributions under the Paris Agreement. This would be calculated by reference to Australia’s share to keep global warming as close to 1.5 degrees as possible. They argued an ‘alternative’ second duty of care required the government to build sea walls to protect the Torres Strait, which it had breached by failing to provide predictable and adequate funding for infrastructure.
The claim in Pabai shares some similarities with that made in the Sharma litigation (2021-22). Sharma involved representative proceedings brought by eight youth plaintiffs on behalf of Australian children. The youth plaintiffs argued that the Federal Minister for the Environment owed Australian children a duty to take reasonable care to avoid personal injury or death resulting to them from emissions when the Minister exercised discretionary powers to approve fossil fuel projects under relevant legislation.
An important difference between Sharma and Pabai was the class of plaintiffs — Australian children rather than Torres Strait Islander people. The latter group is arguably a more determinate class with a greater degree of proximity to the defendant because of their status as indigenous people. An emerging body of case law recognises their special relationship with the Commonwealth. They could establish harm had already occurred. The nature of the argued duties was also an important difference. The duty argued in Sharma required the public authority to take reasonable care when exercising a statutory power, and therefore needed to be consistent — or ‘coherent’ — with the Act. The plaintiffs in Pabai did not argue duties governed by a particular piece of legislation.
‘Core policy’ in Pabai and Sharma
Both Pabai and Sharma saw the plaintiffs being ultimately unsuccessful in establishing the argued duties of care. Despite differences in the claimed duties, both the reasoning of the single justice in Pabai and the reasoning of two of the members of the Full Court in Sharma relied on the concept of ‘core policy’ to justify their conclusions.
Justice Wigney in Pabai was unable to provide a clear definition or distinction between policy and operational matters, finding that the search for a definition was ‘distract[ing]’ (at [118]). But his Honour relied upon it as authority. His Honour accepted that there were ‘some categories’ of government conduct that involve ‘policy or political considerations’ that are nonetheless immune (at [118]-[119]). His Honour held that both argued duties fell within this category. Regarding the duty to set emissions targets in line with the best available science, Wigney J held that assessing this would ‘throw up the issues’ of the nature of Australia’s international obligations, the extent that those obligations required adherence to the best available science, and whether the Commonwealth could take other considerations — including ‘budgetary, economic, social and even political considerations’ — into account (at [854]). The alternative duty to fund the construction of seawalls was influenced by federal allocation of responsibility for climate policy, the division of which was regarded as ‘inherently political’. For this reason, his Honour considered it would be ‘inappropriate and impractical’ to impose a duty of care (at [1161]).
In Sharma, Allsop CJ and Wheelahan J also rejected the argued duty on the grounds that it involved considerations of ‘core policy’. For Allsop CJ, assessing whether the Minister had breached the duty by approving a particular coal mine would involve ‘questions of policy (scientific, economic, social, industrial and political) which are unsuitable for the Judicial branch to resolve in private litigation’ (at [15]). Justice Wheelahan’s reliance on the concept of policy was less central to his Honour’s reasoning. However, his Honour similarly referred to matters that were raised in the relevant legislation — such as ‘principles of ecologically sustainable development’ and ‘the principle of inter-generational equity’ — as questions whose ‘resolution is uniquely suited to elected representatives’ and ‘inevitably slide into political considerations’ (at [868]).
The approach of Wigney J in Pabai and Allsop CJ in Sharma share particularly stark similarities. Significantly, both justices approached the question of whether the duty involved ‘core policy’ prior to the salient feature analysis. In Pabai, the Federal Court went so far as to describe it as a ‘key threshold issue’ for the duty (at [846]). This sits at odds with some High Court authority questioning the utility of the concept, some of which the Federal Court in Pabai cites. In Crimmins, McHugh J rejected the policy / operational distinction on the grounds that it imports ‘public law concepts’ into private law notions of duty, and these have different rationales (at [82]). His Honour suggested that there may be scope for a very narrowly defined ‘core area’ of policy immune from common law duties, but that it would be preferable to accommodate the special circumstances of a public authority defendant at the next stage of analysis — when assessing whether the duty had been breached (at [87]). I discuss this further below.
‘Climate overloading’ and ‘core policy’
One way of explaining why abstract notions of separation of powers played such a pivotal role in both Pabai and Sharma is to explore the broader phenomenon of ‘climate overloading’ that I described above. The government defendants in both cases relied on this strategy to ‘overload’ how relevant duties of care were framed, blurring more concrete questions that a court could assess with the problem of climate change as a whole. As an undifferentiated bloc of ‘climate policy’, the decisions of public authorities that are relevant to climate harms are thus cordoned off and immune from attracting liability because the courts cannot adjudicate on the bloc as a whole. In Pabai, for instance, the Commonwealth argued that setting emissions reductions targets fell within a broad “class of government action over which it would be inappropriate to overlay the laws of negligence …” (at [47]). The conduct of setting emissions reduction targets was ‘overloaded’ with the policy settings for the climate response as whole. The plaintiffs, in contrast, sought to concretise that question by reference to the ‘best available science’ — defined by reference to a number of Australian and international authoritative bodies — which provided a clear criterion against which to measure government action (at [100]). Framed in this way, the reasonableness of the Commonwealth’s conduct would be easier to measure. The Federal Court was not convinced, preferring the Commonwealth’s framing of the question.
‘Climate overloading’ is a favoured strategy of government defendants across the world and is surprisingly agnostic regarding litigated doctrine. It has appeared in cases involving fundamental rights, statutory interpretation and executive powers, civil and common law duties of care, and public trust doctrines. There are various reasons why climate overloading strategies succeed, some of which connect with the narratives legal cultures are employing to navigate the messiness of climate change. As Liz Fisher recently noted, the narrative of ‘strategic litigation as a mechanism for forcing public action’ can produce simplified accounts of the role of courts in a climate changing world that aggravate separation of powers concerns.
‘Climate overloading’ presents particular challenges in a common law context because of the common law’s aversion to abstract reasoning. As the Federal Court in Pabai stressed (at [1275]), the common law’s approach to problems that emerge in the world is slow and incremental. Abstract claims about the role of courts in the climate crisis — which are common in theory and commentary on climate litigation — detach the focus of inquiry away from the fact-driven analogical approach with which common law courts are comfortable. Superior courts in civil law systems are arguably better equipped to deal with climate overloading because they can counter abstract claims about separation of powers in kind. Some of these courts have done so by reference to the concept of the rule of law while others have noted the separation of powers problem with concentrating entire subject matters in one or two institutional branches.
In the common law tradition, however, courts do not reason through separation of powers in the abstract. The distribution of questions between arms of government emerges through the aggregate effect of many small, factually grounded decisions. When the question is ‘overloaded’ — so that the court is not merely being asked to consider whether the reasonable authority would have set reduction targets that are compatible with the best available science, but to adjudicate on the national climate policy response as a whole — the court is quickly overwhelmed and unable to find for the plaintiffs. The irony is that, by relying on concepts such as ‘core policy’ to express concerns about that overloaded framing and its institutional role, the court responds in an abstraction detached from clear fact-based principles that makes future slow and incremental development very difficult. The meaning and edges of ‘core policy’ in the context of the liability of public authorities for climate-related harms is unclear for future plaintiffs, defendants and courts.
The limits of legal absolutes in a climate changed world
In Crimmins, McHugh J suggested that it would be preferable to take into account the special circumstances of a public authority in negligence claims at the breach stage of analysis, rather than at the duty stage. His Honour suggested a different test may be relevant in affirmative duty cases — where the defendant was under a duty to take positive steps (at [93]). Outside of those cases, the defendant’s nature as a public authority can be addressed by taking the fact that the defendant is a public authority into account when determining the standard of reasonableness (at [90]). This is already the practice when determining the liability of public authorities under state-based Wrongs Acts following the Ipp Review. Scholars (here and here) have made similar suggestions about considering the public authority character of the defendant at the breach rather than duty stage.
These suggestions, formulated as a points of principle and legal clarity, acquire particular relevance in the context of liability for climate harms. Forecasted climate harms in Australia will result in extreme damage to property, health and lives — heads of damage that law already recognises. The decisions of public authorities as well as other powerful societal actors will come under scrutiny as tort continues its role as a loss distribution mechanism. The wave of social and economic problems that industrialisation and economies of scale cast up in the nineteenth-century had much of a hand in common law negligence law as we know it today. Climate change will likely have a similar effect. In a context where the law will be be under increasing pressure to develop, absolutist and categorical approaches to reasoning are undesirable. Accommodating the fact that the defendant is a public authority at the breach stage of analysis, rather than the duty stage, would tie the reasoning in specific cases much more closely to the facts. This would prevent the need for the courts to have recourse to absolutist concepts to express concerns about their institutional role.
Liz Hicks is a Lecturer at Melbourne Law School, where she is a member of the Centres for Law and the Environment and for Comparative Constitutional Studies.
Suggested citation: Liz Hicks, ‘“Climate Overloading” and Separation of Powers Arguments: Reflections on Pabai v Commonwealth of Australia’ (25 September 2025) <https://www.auspublaw.org/blog/2025/09/climate-overloading-and-separation-of-powers-arguments-reflections-on-pabai-v-commonwealth-of-australia>