This article outlines and examines the recent (2020-2021) developments in international environmental law, including Stop Ecocide’s campaign for a new international crime of ecocide and the Independent Expert Panel’s proposed definition of ecocide. Harrison notes that the disjunctive phrasing in the definition leads to prohibiting acts which are either unlawful or wanton. Since an act may be wanton even though it is legal, this provides an important safety net to prevent perpetrators of severe and widespread or long-term harm from evading justice, simply because their actions were not in breach of existing international or national law. Harrison identifies the amendment process and subsequent required ratification by states as a hurdle to making this definition operational and notes that even then, the workability of the definition will depend on decisions of the Court and the Office of the Prosecutor.