The Precautionary Principle in Australian law

The Precautionary Principle is an evolving concept: first arising in German law, migrating to international environmental declarations, and then becoming part of national legislative interventions for the purposes of environmental protection.

Australia enthusiastically adopted the term ‘precautionary principle’ in legislation in the 1990’s, but it missed a significant point – it’s a guideline in aid of a more general duty. That needs to be the focus of both legislative interpretation of the present law, and also future law reform.

The precautionary principle in an international context

The descriptive phrase ‘precautionary principle, as used now, is not the name originally given to the concept. Some reference to the concept of the precautionary principle was used in international treaties in the 1980’s and 1990’s, and gradually refined over that period. It was referred to then as a ‘precautionary approach’ to measures intended to prevent environmental degradation.

In December 2015 (translated February 2016), European Parliamentary Researcher Didier Bourguignon prepared an in-depth analysis of the precautionary principle for the European Union in a document titled The precautionary principle: Definitions, applications and governance[1]. He referred to the origins of the precautionary principle in a related concept (the foresight principle) in 1970’s German Law. He stated that the first reference to precautionary principles, approaches or measures was in the 1985 Vienna Convention for the protection of the Ozone Layer[2].

Goldstein [3] noted that the Precautionary Principle was first stated in the 1989 Rio Declaration [4]:

Nations shall use the precautionary approach to protect the environment. Where there are threats of serious or irreversible damage, scientific uncertainty shall not be used to postpone cost-effective measures to prevent environmental degradation.

In the 1992 Rio Declaration on Environment and Development, it was contained within Principle 15:

In order to protect the environment, the precautionary approach shall be widely applied by States according to their capabilities. Where there are threats of serious or irreversible damage, lack of full scientific certainty shall not be used as a reason for postponing cost-effective measures to prevent environmental degradation.

Significantly, however, Principle 15 was listed after other preliminary principles that emphasised States’ ‘right to development’. Also, the more general topic of ‘environmental degradation’ was addressed in the earlier principles, including, for example, Principle 14:

States should effectively cooperate to discourage or prevent the relocation and transfer to other States of any activities and substances that cause severe environmental degradation or are found to be harmful to human health.

In that principle, the primary concern was ‘any activities …that cause severe environmental degradation’. The prevention of environmental degradation was paramount, as it really is in Principle 15, where the relevant phrase indicating the ultimate purpose is ‘measures to prevent environmental degradation’. Similarly, in Principle 23 the ultimate objective is protection of the environment:

The environment and natural resources of people under oppression, domination and occupation shall be protected.

By the early 2000’s the concept was being referred to as the ‘precautionary principle’. A 2001 paper by Kriegel that examined that question said:

The term precautionary principle [as distinct from the term ‘prudent avoidance’] has the advantage that it provides an overarching framework that links environmental sciences and public health.[6]

Kriegel also noted:

The precautionary principle, by calling for preventive action even when there is uncertainty, by placing the onus on those who create the hazard, and by emphasizing alternatives and democracy, is viewed by environmentalists as a way to shift the terms of the debate and stimulate change.

The context for the principle

Before the need for the precautionary principle even arises, there must exist some consensus or agreement (including that found in international treaties since the 1980’s) that it is necessary to exercise some constraint on the normative behaviours that would otherwise degrade the environment. It is a guideline premised on that more general purpose.

The precautionary principle is not the logical starting point for reasoning about duties of environmental protection.

We have three elements:

  • The general duty to protect the environment and/or avoid economic degradation (whether conditionally or unconditionally);
  • The easy cases, where there is relative scientific certainty regarding what the harm is, and how to avoid it (obvious ‘foreseeability’ and higher probability); and
  • The hard cases, where there is a degree of scientific uncertainty regarding what the harm is, and/or how to avoid it (less certainty).

If we accept that the precautionary principle is intended to provide guidance in ‘hard cases’, and with respect to a general duty to prevent environmental degradation, then we can more easily appreciate that there are most likely other easier cases that are equally captured within the same general circumstances. Where there is, for example, even more scientific certainty, there should be an even stronger argument that there exists the same general duty to try and implement cost-effective measures to avert environmental degradation.

The utility of the pr. principle is directed to ‘hard cases’

Attempts to define the precautionary principle in terms of over-arching principles suffer from the problem of giving it a more general scope than intended. Attempts to elevate it to the sole foundational principle for the prevention of environmental degradation are likely to lead into more confusion and error.

When international treaties invoke the precautionary principle, it is intended to provide guidance as to law-making policies for member states. It emphasises the values that need to be held highest – that environment degradation is a sufficiently serious topic that it requires action rather than inaction. Significantly, its focus is on these ‘hard cases’ – the ones involving scientific uncertainty.

Legislative ratification of the precautionary principle requires some appreciation of this context, in order to provide a comprehensive, rational system for using it. You cannot intelligently legislate using the ‘precautionary principle’ without also having endorsed a more general duty to prevent environmental degradation.

Australian legislative responses

In Australian law, references to the need to preserve biological diversity and ecological integrity sometimes occur in the same context as the precautionary principle. These considerations ought to be more closely related to the more general duty to prevent environmental degradation than the precautionary principle itself. That they may sometimes be included with it suggests that the anticipation of environmental harm, in the future, and taking reasonably necessary steps to prevent it, is the unifying principle or duty for all these elements.

The language in the Rio Declaration Principles influenced the Australian National Strategy for Ecologically Sustainable Development [5]. This strategy preceded the Environmental Protection and Biodiversity Conservation Act 1999 (Cth) (EPBC Act) by a few years. In section 3A of the EPBC Act some of the Rio Declaration Principles (the ‘Rio Subset‘) are reproduced in summary form:

3A Principles of ecologically sustainable development

The following principles are principles of ecologically sustainable development:

(a)  decision‑making processes should effectively integrate both long‑term and short‑term economic, environmental, social and equitable considerations;

(b)  if there are threats of serious or irreversible environmental damage, lack of full scientific certainty should not be used as a reason for postponing measures to prevent environmental degradation;

(c)  the principle of inter‑generational equity—that the present generation should ensure that the health, diversity and productivity of the environment is maintained or enhanced for the benefit of future generations;

(d)  the conservation of biological diversity and ecological integrity should be a fundamental consideration in decision‑making;

(e)  improved valuation, pricing and incentive mechanisms should be promoted.

A more prepared legislature would have considered all of the necessary foundational concepts that needed to be expressly incorporated into the legislation. As part of this, it would have placed the precautionary principle in the service of the more general duty.

As a general matter, a list of ‘principles’ agreed for the purposes of an international treaty may require a more logically structured representation in local legislation in order to ensure better comprehension and clarity.

The need to expose the implicit general protective duty in State-based legislation

A more general duty of environmental protection (and/or to prevent environmental degradation) is implicit in the use of the precautionary principle in most of The Australian statutes that refer to it. As a matter of general interpretation, this general duty and purpose should be accepted in each legislative document in which the precautionary principle is applied to environmental matters (whether that be a statute, code, plan etc).

This should be a matter capable of legislative re-interpretation in light of the changes since 1992, and the adoption of the National Strategy, and in subsequent legislative instruments embodying environmental protection laws. This includes the Environmental Protection and Biodiversity Conservation Act 1999 (Cth).

The same scheme as section 3A of the EPBC Act is reproduced in section 4 of the Environmental Protection Act 1986 (WA), where it states that the object of the Act is ‘to protect the environment of the State, having regard to the following principles’, and then reproduces the same few principles from the Rio Subset as the EPBC Act. However, it leaves out the first principle (long and short term goals) that appears in the EPBC Act, and includes another principle at the end (waste minimisation).

The re-evaluation of normative values requires a comprehensive review of the extent to which legislative instruments expressly avert to the general duty to protect the environment, and whether there is a need for a logical structure that is more useful than the checklist approach adopted by the drafters of the legislation. In my view, we need to identify that this set of principles does not convey the whole of the matters described there (including the context of the precautionary principle and, in turn, the relevance of the distinction between matters with scientific certainty, and scientific uncertainty). This task remains incomplete.

The role of progressive test cases cannot be underestimated. Since explicit amendments to legislation to clarify the situation have not been made, it may require specific cases to undertaken statutory interpretation exercises until this reaches a level of consensus in the common law.

Subsidiary legislative documents

Where a statute also contemplates further and subsidiary legislative documents be prepared (like management plans, codes, development plans, conservation plans etc), then in each case, it should require the same general values to be consistently be applied all the way down the legislative chain.

This recognition that there is a unifying general duty involved should make it easier to flexibly design subsidiary legislative documents. There should be some balanced and complementary attention given to the ‘hard cases’ and the ‘easy cases’, and the precautionary principle is only required for the ‘hard cases’. There does not have to be any ongoing difficulty in finding ways to express the precautionary principle at different levels of generality or different levels of decision-making. If it is not needed, then there is still a positive general duty to take action to prevent environmental degradation for the remaining ‘easy cases’.

Project-level legislative documents

In relation to clearing, legislative regulation of environmental protection has been pushed down, into the contents of management plans and development project action plans that are intended to bind project proponents. In Victoria, Regional Forestry Agreements and ‘Codes of Conduct’ are the practical records of what is largely a pattern of self-regulation by those that have the means to degrade the environment as part of ‘business as usual’.

The preparation of management plans for conservation is part of the legislative process, and development approval processes. This activity is still subject to judicial review, because it is a requirement of other, more general duties.

Legal review of these plans has often been focussed on the compliance with the ‘precautionary principle’ because this is an explicit phrase found in the legislative documents, like the Code. However, reliance on this phrase tends to narrow the focus to a subset of the circumstances to the ‘hard cases’ too early. This has led to confusion (or legal arguments) about whether uncertainty, as well as a serious threat is a precondition to the precautionary principle. Yet the precautionary principle is most relevant in that situation. This is merely to remind us that it applies to a subset of circumstances in which the prevention of environmental degradation is to be considered.

The Possums Case

In the Possums Case[9], the parties were in dispute about the requirements of a Code of Conduct, and forestry logging plan. These plans were intended, in part, to prevent invalid environmental degradation (the loss of endangered species). In that context, the parties were also in dispute about whether the ‘precautionary principle’ applied to give rise to a duty that was breached by the relevant conduct.

The Federal Court (Mortimer J) found that the forestry and conservation plans themselves were not actually working to protect endangered species on the ground, nor did it seem they had been designed with any track record of being effective. He found that VicForests was in breach of the Code of Conduct, and was likely to continue to be in the future.

It is likely that this conduct would have failed the more general duty to prevent environmental degradation, but the case was not dealt with that way.

The case focussed on the application of the precautionary principle. This was because the precautionary principle demanded action in that case, rather than postponement. It was, in effect, treated as one of the ‘hard cases’, and one in which there was sufficient uncertainty (about how to prevent the harm, which was serious), that postponement of action could not be justified.

The case illustrates that even in a case with scientific uncertainty, there is a need to both plan and act; planning alone will not be enough, and poor planning will need to be reviewed and revised.

The variable need for the precautionary principle

If we accept the precautionary principle is a guideline for some circumstances to which a more general duty attaches, then of course it will have more scope for application in some cases than others. This does not mean we have to jettison our compliance with the more general duty to avoid environmental degradation.

It is obviously possible that with more knowledge, time and information, cases for which the precautionary principle was once apposite (‘hard cases’) will become ‘easy cases’, and specific guidance from the precautionary principle (in implementation of laws or operational actions) will not be needed. That is because we will simply be able to comply with a more general duty to prevent environmental degradation, in a situation of greater certainty.

We should always be asking if circumstances have proceeded from uncertainty to certainty (from the ‘hard case’ to the ‘easy case’). The general duty to prevent environmental degradation is a continuing one – the fact that the precautionary principle might have applied in the context of a project approval, or decision requiring environmental approval simply means the parties were dealing with a ‘hard case’ at that time. Having done so, there is no reason why they are release from the need to pay attention to the purpose for which action was taken. It is still relevant to ask whether they did or did not succeed in preventing the environmental degradation that was of concern.

Conclusion and summary

It is imperative for environmental legal cases that involve interpretations of the phrase ‘precautionary principle’ that the more general duty to prevent environmental degradation, implicit in the use of that term, is given express recognition, as a matter of legislative interpretation.

The phrase ‘precautionary principle’ should be understood as providing guidance in respect to ‘hard cases’, but that doesn’t mean attention shouldn’t be given to discharging the more general duty to prevent environmental degradation in the ‘easy cases’.

The more general duty (and the application of the precautionary principle to provide guidance in the ‘hard cases’) is a continuing duty to prevent environmental degradation. This is essential to ensure that it is workable, but also to ensure that the precautionary principle can be used as appropriate, based on the available information at any given time.

The precautionary principle may have variable application, even for the same subject matter, because knowledge changes over time. Where the precautionary principle might once have been needed, over time, greater certainty might enable us to clearly state there is an obvious duty to act in a particular way to prevent environmental degradation.


  1. Bourguignon (European Union), The precautionary principle: Definitions, applications and governance (2016), doi:10.2861/821468 URL:
  2. Bourguignon, ibid, paragraph 2.1.
  3. Environ Health Perspect 107:A594–595 (1999). Available at URL: (5 July 2020)
  4. United Nations Conference on Environment and Development. Earth Summit. Rio Declaration on Environment and Development, Rio de Janeiro, Brazil. Publ no. E.73.1.A.14.Stockholm:United Nations,192.
  5. URL:
  6. (2001), Kriebel et al, The Precautionary Principle in Environment Science, Environmental Health Perspectives, 109(9) page 871
  7. URL Accessed 5 July 2020
  8. Raffensperger C, Tickner J, eds. Protecting Public Health and the Environment: Implementing the Precautionary Principle. Washington, DC:Island Press, 1999.
  9. Friends of Leadbeater’s Possum Inc v VicForests (No 4) [2020] FCA 704 (27 May 2020) (“Possums Case”)
  10. Reproduction of the Rio Declaration at the Conference on Biological Diversity website URL:

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