CYIL vol. 11 (2020)

CYIL 11 (2020) THE NEW TREND OF INTERNATIONAL ENVIRONMENTAL LAW … Sustainable development, as emphasized, is of great importance for the construction of international environmental law’s own (self-contained) normative system. On this principle- system relation, Voigt teaches: International law as a normative system is not static. It evolves and grows in response to modern challenges. One of the areas where international law is developing is in the extension of its ambit to individuals, regional communities and the wider civil society. […] The repetitious references to sustainable development throughout a multitude of international and domestic laws, regulations, conventions and non- binding documents is evidence of its general acceptance as a normative concept. 57 Remarkably, some principles have been given a hard time both by supporters and opponents of international environmental law’s custom-founded theorization. In the International Court of Justice, for example, there is the famous Separate Opinion of Vice-President Weeramantry, who defended in the Gabčíkovo-Nagymaros Project case that sustainable development holds the nature of a principle of customary law. 58 Another, more recent example is the discussion around the precautionary principle in international environmental issues. The International Court of Justice, in the judgment of a leading case known as Nuclear Tests (New Zealand v. France) 59 has also decided the controversy on a custom basis. Judge Palmer’s dissenting opinion, for instance, considered the construction of a new position that grants the precautionary principle the status of customary international law. Upon understanding that the precautionary principle and a preliminary environmental assessment should be adopted in advance of environmentally risky activities, Judge Palmer referred to a customary international law and not to one arising from treaties. In the Southern Bluefin Tuna Cases (New Zealand v. Japan; Australia v. Japan) , 60 the decision followed the same directive when the precautionary principle was considered international custom, justification being the fact that said principle was more decisively incorporated in a series of multilateral instruments on marine management and conservation in the last decades. 61 On the theme, Simon Marr adds: However, in view of recent state practice and opinio juris , there are in the author’s opinion good grounds for arguing that the precautionary approach, in relation to marine living resources has developed from an evolving norm to an established norm of customary international law. 62 The approach of the International Tribunal for the Law of the Sea needs no further comment. If a certain principle appears in several (not necessarily all) international treaties 57 Ibid 145-146. 58 Gabčíkovo-Nagymaros Project (Hungary v Slovakia) (Judgment of 25 September 1997) (Separate Opinion of Vice-President Weeramantry) [1997] ICJ Rep 1997, 92. 59 Nuclear Tests (New Zealand v. France) (Judgment of 20 December 1974) [1974] ICJ Rep 1974, 457. 60 Southern Bluefin Tuna Cases – Case No 3 & 4 (New Zealand v Japan; Australia v Japan), (Provisional Measures, Order of 27 August 1999) ITLOS Reports 1999, 280. 61 MARR, Simon, ‘The Southern Bluefin Tuna Cases: The Precautionary Approach and Conservation and Management of Fish Resources’ (2000) 11/4 European Journal of International Law 815, 824. 62 Ibid 827.

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