Related Rule
New Zealand
Practice Relating to Rule 44. Due Regard for the Natural Environment in Military Operations
In its written statement submitted to the ICJ in the Nuclear Tests case (Request for an Examination of the Situation), New Zealand argued, in its request for an examination of the situation, that, under customary international law, a State is under an obligation to carry out an environmental impact assessment “in relation to any activity which is likely to cause significant damage to the environment, particularly where such effects are likely to be transboundary in nature”. 
New Zealand, Written statement submitted to the ICJ, Nuclear Tests case (Request for an Examination of the Situation), undated, § 89.
New Zealand also referred to the “precautionary principle” as a “very widely accepted and operative principle of international law” and which has the effect that “in situations that may possibly be significantly environmentally threatening, the burden is placed upon the party seeking to carry out the conduct that could give rise to environmental damage to prove that that conduct will not lead to such a result”. 
New Zealand, Written statement submitted to the ICJ, Nuclear Tests case (Request for an Examination of the Situation), undated, § 105.
New Zealand indicated that France had accepted this rule because it was contained in French law No. 95-101 of 1995 in the following terms:
The precautionary principle, according to which the absence of certainty, having regard to scientific and technical knowledge at the time, should not hold up the adoption of effective and proportionate measures with a view to avoiding a risk of serious and irreversible damage to the environment at an economically acceptable cost. 
New Zealand, Written statement submitted to the ICJ, Nuclear Tests case (Request for an Examination of the Situation), undated, § 107.