Higgins distinguishes between ascertainable and non-ascertainable ecocide, with the former having a clear human cause while the latter does not. An example of non-ascertainable ecocide is destruction due to extreme weather events related to climate change. Arthur H. Westing discussed the element of intent in relation to ecocide, stating that "Intent may not only be impossible to establish without admission but, I believe, it is essentially irrelevant." International law There is no international law against ecocide that applies in peacetime, but the Rome Statute makes it a crime to In 1977 the United Nations adopted the Convention on the Prohibition of Military or any other Hostile use of Environmental Modification Technique. Article I of this Convention says, "Each State Party to this Convention undertakes not to engage in military or any other hostile use of environmental modification techniques having widespread, long-lasting or severe effects as the means of destruction, damage or injury to any other State Party." There is no definition of the terms 'widespread, long-lasting or severe'. Efforts to expand international ecocide law Efforts to criminalise ecocide have sought to include the crime among those prosecuted by the International Criminal Court established by the Rome Statute. These crimes include genocide, crimes against humanity, war crimes, and the crime of aggression. In 2010, environmental lawyer Polly Higgins submitted a proposal to the United Nations International Law Commission that defined ecocide as:The extensive damage to, destruction of or loss of ecosystems of a given territory, whether by human agency or by any other causes, to such an extent that peaceful enjoyment by the inhabitants of that territory has been severely diminished.The full proposal, which was submitted to the International Law Commission, is set out in chapters 5 and 6 of her book Eradicating Ecocide: Laws and Governance to Prevent the Destruction of our Planet, Polly Higgins, Published by Shepheard Walwyn: 2010. This definition includes damage caused by individuals, corporations and/or the state. It also includes environmental destruction from 'other causes' (i.e. harm that is not necessarily caused by human activity). The purpose was to create a duty of care to mitigate or prevent naturally occurring disasters as well as creating criminal responsibility for human-caused ecocide. In December 2019 at the 18th session of the Assembly of States Parties to the Rome Statute of the International Criminal Court, Vanuatu and the Maldives called for ecocide to be added to the Statute. In