Règle correspondante
Practice Relating to Rule 45. Causing Serious Damage to the Natural Environment
Sweden’s IHL Manual (1991) refers to Article 55 of the 1977 Additional Protocol I as providing that “the parties shall exercise caution so that widespread, long-term and severe damage [to the natural environment] can be avoided”. 
Sweden, International Humanitarian Law in Armed Conflict, with reference to the Swedish Total Defence System, Swedish Ministry of Defence, January 1991, Section, p. 62.
At the CDDH, while expressing satisfaction at the adoption of the two 1977 Additional Protocols, Sweden pointed out that “there were now for the first time explicit rules against … environmental warfare”. 
Sweden, Statement at the CDDH, Official Records, Vol. VII, CDDH/SR.58, 9 June 1977, p. 307, § 133.
In its written statement submitted to the ICJ in the Nuclear Weapons case in 1995, Sweden stated:
In accordance with an established basic principle, expressed, for example, in the Declaration made by the 1972 UN Conference on the Human Environment, there are impediments to the use of weapons which cause extensive, long-term and serious damage to the environment. 
Sweden, Written statement submitted to the ICJ, Nuclear Weapons case, 20 June 1995, p. 5; see also Written statement submitted to the ICJ, Nuclear Weapons (WHO) case, 20 September 1994, p. 5 (extracts from the Report of the Swedish Parliamentary Standing Committee on Foreign Affairs).