§ 2. Crimes
Section 5
5. Anyone who, in the case of an international armed conflict, commits one of the following acts:
(b) intentionally launching an attack in the knowledge that such an attack will cause incidental loss of life or injury to civilians or damage to civilian objects or widespread, long-term and severe damage to the natural environment which would be clearly excessive in relation to the concrete and direct overall military advantage anticipated;
shall be liable to a term of imprisonment not exceeding fifteen years or a fifth category fine.

Article 8
War crimes
2. For the purpose of this Statute, "war crimes" means:
(b) Other serious violations of the laws and customs applicable in international armed conflict, within the established framework of international law, namely, any of the following acts:
(iv) Intentionally launching an attack in the knowledge that such attack will cause incidental loss of life or injury to civilians or damage to civilian objects or widespread, long-term and severe damage to the natural environment which would be clearly excessive in relation to the concrete and direct overall military advantage anticipated

This provision follows the ICC Statute.