Scientific Uncertainty

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From

The Precautionary Principle, The Coast and Temwood Holdings by The Hon. Justice Stephen Estcourt, Judge, Supreme Court of Tasmania, delivered at the Australasian Conference of Planning and Environment Courts and Tribunals, Henry Jones Art Hotel, Hobart, 5 - 7 March 2014

As to the first condition precedent, or threshold, to the engagement of the principle, namely "the threat of serious or irreversible environmental damage", Osborn J, after a consideration of Preston CJ's factors pointing to the existence of a threat, adopted the language of the Shirt calculus. His Honour said:

"In my view the statement in another context by Mason J in Wyong Shire Council v Shirt, that a risk though remote may nevertheless be real and not fanciful or far-fetched is apposite here. At 48 his Honour stated that '[a] risk which is not far-fetched or fanciful is real and therefore foreseeable.'" [60]

As to the second of the conditions precedent, namely, that there be "a lack of full scientific certainty", Osborn J noted that, as with the first condition precedent, it was a question of fact, potentially involving complex factors, and he set out Preston CJ's postulation of those factors.[61] He then referred to Preston CJ's summation of the body of theoretical debate as to what is the requisite degree of uncertainty required to trigger application of the principle [62], and concluded, pragmatically:

"In the present case I propose to analyse the evidence on the basis of a standard of substantial uncertainty. Such a standard falls within the ambit of the principle whatever may be its theoretical limits." [Emphasis added.]

Next, from the Telstra case [64], Osborn J noted that if the two conditions precedent were satisfied, then the burden of showing that damage would not occur "effectively shifts to VicForests to show that the threat of environmental damage does not exist or is negligible".
His Honour then [66] helpfully epitomised the pivotal principles to be derived from Preston CJ's exegesis, as follows:

• The precautionary principle permits the taking of preventative measures without having to wait until the reality and seriousness of the threat have been fully known.

• The precautionary principle is not directed to the avoidance of all risks.

• The degree of precaution appropriate will depend on the combined effect of the seriousness of the threat and the degree of uncertainty.

• The margin for error in respect of a particular proposal may be controlled by an adaptive management approach.

• The precautionary principle requires a proportionate response. Measures should not go beyond what is appropriate and necessary in order to achieve the objective in question. The principle requires the avoidance of serious or irreversible damage to the environment wherever practicable. It also requires the assessment of the risk-weighted consequences of optional courses of action.

• A reasonable balance must be struck between the cost burden of the measures and the benefit derived from them.

• The relevant notion of proportionality is however not readily captured by traditional cost benefit analysis.

• The triggering of the precautionary principle does not necessarily preclude the carrying out of a particular land use or development proposal.

• The precautionary principle may also require consideration in the context of other principles of environmentally sustainable development.

Osborn J then proceeded to operationalise the precautionary principle in the case before him, adopting a checklist approach. His Honour said:

"In summary, the application of the precautionary principle to aspects of this case raises the following fundamental issues:

(a) is there a real threat of serious or irreversible damage to the environment?

(b) is it attended by a lack of full scientific certainty (in the sense of material uncertainty)?

(c) if yes to (a) and (b), has VicForests demonstrated the threat is negligible?

(d) is the threat able to be addressed by adaptive management?

(e) is the measure alleged to be required proportionate to the threat in issue?"