Related Rule
Nauru
Practice Relating to Rule 45. Causing Serious Damage to the Natural Environment
In its response to submissions of other States to the ICJ in the Nuclear Weapons (WHO) case in 1995, Nauru stated: “It is also a violation of customary international law … to use weapons that cause severe damage to the environment”. 
Nauru, Written comments on other written statements submitted to the ICJ, Nuclear Weapons (WHO) case, 15 June 1995, Part 1, p. 11.
In its response to submissions of other States to the ICJ in the Nuclear Weapons (WHO) case in 1995, Nauru stated:
It is a general principle of law that the foreseeable consequences of an act are interpreted as an intention to bring them about. It is disingenuous, therefore, in view of what scientists have described as the enormously damaging environmental and climatic consequences of a nuclear exchange to assert that these would be mere “unintended side effects”. 
Nauru, Written comments on other written statements submitted to the ICJ, Nuclear Weapons (WHO) case, 15 June 1995, Part 2, p. 28.