Relevant International Crime history
1945 United Nations Charter: “The General Assembly shall initiate studies and make recommendations for the purpose of a. encouraging the progressive development of international law and its codification” United Nations Charter Article 13, 1.
1947 General Assembly Resolution 174 (II): establishing the International Law Commission and approving its Statute. General Assembly Resolution 177 (II): preparation of a Draft Code of Crimes against the Peace and Security of Mankind (renamed the Rome Statute from 1998). A/RES/177 (II) General Assembly Resolution 178 (II): draft declaration on the rights and duties of States.
1948 The International Law Commission is established by the United Nations General Assembly for the “promotion of the progressive development of international law and its codification.” A/RES/174(II).
1970s onwards: there was growing support from government, the United Nations and communities to include Ecocide as the fifth International crime to stand alongside the crime of Genocide by amending the Rome Statute. It is recognised as part of an emerging body of Earth Law or Earth Jurisprudence. In an obiter dictum in the 1970 Barcelona Traction case judgment, the International Court of Justice identified a category of international obligations as ‘erga omnes’, namely obligations owed by states to the international community as a whole, intended to protect and promote the basic values and common interests of all.
1978 Draft Code of Crimes Against the Peace and Security of Mankind discussions commence. At the same time, State responsibility and international crimes are discussed and drafted. A/CN.4/SER.A/1978/Add.l (Part 2), Page 80, Article 19.2.(d)
1996 All aspect of ecocide/environmental crime are removed from the Draft Code of Crimes Against the Peace and Security of Mankind. In the same year Article 19, ‘International Crimes of State’, of the draft Articles Articles on the Responsibility of States for Internationally Wrongful Acts is removed. Article 19 read “an internationally wrongful act which results from the breach by a State of an international obligation so essential for the protection of fundamental interests of the international community that its breach is recognized as a crime by that community as a whole.” 
1998 Draft Code of Crimes Against the Peace and Security of Mankind, renamed the Rome Statute, includes only four international crimes (minus ecocide) and is the founding document of the International Criminal Court (ICC). The ICC is classified as a Court of last resort – to be used when a state is either unwilling or unable to bring their prosecutions for international crimes.
2001 Articles on the Responsibility of States for Internationally Wrongful Acts published. Article 19 (State crimes) is not included.
2002 The Rome Statute of the International Criminal Court  entered into force, including only four international crimes of ‘the most serious crimes of concern to the international community as a whole’.
Relevant Ecocide law and State Responsibility history
The concept of creating an international crime of Ecocide has a history dating back to the 1970s.
1970 The word ‘ecocide’ was recorded at the Conference on War and National Responsibility in Washington 1970, where Arthur Galston proposed a new international agreement to ban ecocide. Galston was a US biologist who identified the defoliant effects of a chemical later developed into Agent Orange. Subsequently a bioethicist, he was the first in 1970 to name massive damage and destruction of ecosystems as an ecocide.
1972 In 1972 at the United Nations Stockholm Conference on the Human Environment (which adopted the Stockholm Declaration) Olof Palme the Prime Minister of Sweden, in his opening speech spoke explicitly of the Vietnam war as an ecocide and it was discussed in the unofficial events running parallel to the official UN Stockholm Conference on Human Environment. Others, including Indira Gandhi from India and Tang Ke, the leader of the Chinese delegation, also denounced the war in human and environmental terms. They too called for ecocide to be an international crime. A Working Group on Crimes Against the Environment was formed at the conference, and a draft Ecocide Convention was submitted into the United Nations in 1973.
In 1972 Dai Dong, a branch of the International Fellowship of Reconciliation sponsored a Convention on Ecocidal War which took place in Stockholm, Sweden. The Convention brought together many people including experts Richard A. Falk, expert on the international law of war crimes and Robert Jay Lifton, a psychohistorian. The Convention called for a United Nations Convention on Ecocidal Warfare, which would amongst other matters seek to define and condemn ecocide as an international crime of war. Richard A. Falk drafted an Ecocide Convention in 1973, explicitly stating at the outset to recognise “that man has consciously and unconsciously inflicted irreparable damage to the environment in times of war and peace.” 
It was recognised from the outset that the element of intent did not always apply. “Intent may not only be impossible to establish without admission but, I believe, it is essentially irrelevant.”
1970s The idea of expanding the 1948 Genocide Convention led to extensive enquiry as to whether ecocide should be included as an international crime by the United Nations. The Sub-Commission on Prevention of Discrimination and Protection of Minorities prepared a study discussing the effectiveness of the Genocide Convention, proposing the adoption of ecocide as well as cultural genocide to the list of crimes. In the following years making ecocide a crime was examined by various working groups and mentioned in several studies. Although primary source documents are not fully comprehensive or available, some of the key documents are listed here.
1978 Draft articles on State Responsibility and international crime include: “an international crime (which) may result, inter alia, from: (d) a serious breach of an international obligation of essential importance for the safeguarding and preservation of the human environment, such as those prohibiting massive pollution of the atmosphere or of the seas.” Supporters who spoke out in favour of a crime of ecocide included Romania and the Holy See, Austria, Poland, Rwanda, Congo and Oman, pages. 115-117. Ecocide was debated for consideration in the Sub-Commission on Prevention of Discrimination and Protection of Minorities’ Study of the Question of the Prevention and Punishment of the Crime of Genocide. 4 July 1978.
1985 Ecocide as a crime continued to be addressed. The Whitaker report, commissioned by the Sub-Commission on the Promotion and Protection of Human Rights on the question of the prevention and punishment of the crime of genocide was prepared by then Special Rapporteur, Benjamin Whitaker. “Some members of the Sub-Commission have however proposed that the definition of genocide should be broadened to include cultural genocide or “ethnocide”, and also “ecocide”: adverse alterations, often irreparable, to the environment – for example through nuclear explosions, chemical weapons, serious pollution and acid rain, or destruction of the rain forest – which threaten the existence of entire populations, whether deliberately or with criminal negligence.” page 17, para 33. A draft resolution, prepared for the Commission on Human Rights submitted by Deschênes and Mubanga-Chipoya as part of the review, included the recommendation to have Whitaker expand and deepen the study of the notions of cultural genocide, ethnocide and ecocide. In the UN report on its 38th session, a reference is missing as to whether the Sub-Commission finally determined what route they were to take.
1987 Discussion of international crimes continued in the International Law Commission, where it was proposed that “the list of international crimes include “ecocide”, as a reflection of the need to safeguard and preserve the environment, as well as the first use of nuclear weapons, colonialism, apartheid, economic aggression and mercenarism”. 1987 Yearbook, Vol I, p. 56, para 38.
1991 The Draft Code of Crimes Against the Peace and Security of Mankind contain 12 crimes. 1991 Yearbook: Ecocide was replaced by ’wilful and severe damage to the environment’ (Article 26) without vote. The Draft Articles were transmitted to governments for their comments and observations.
1993 As of 29 March 1993, the Secretary-General had received 23 replies from Member States and one reply from a non-member State. They were: Australia, Austria, Belarus, Belgium, Brazil, Bulgaria, Costa Rica, Ecuador, Greece, Netherlands, the Nordic countries (Denmark, Finland, Iceland, Norway, Sweden), Paraguay, Poland, Senegal, Sudan, Turkey, UK, USA, Uruguay and Switzerland. For summarised commentary of responses see 1993 Yearbook of the ILC. Only three countries, the Netherlands, the United Kingdom and the United States of America, opposed the inclusion of an environmental crime. The Netherlands supported only four crimes (minus ecocide); the USA and the UK objected to the draft Code per se. The USA cited ‘vagueness’ and the UK cited crimes against the environment as being unknown international crime and a step too far. 1993 Yearbook Documents of the 45th session (Part 1).
In tandem, see the extensive records re State Responsibility for significant environmental harm, as discussed at length and recorded in 1993 Yearbook Documents of the 45th session (Part 2).
The issue of adding a high test of intent (‘wilful’) was of concern; e.g Austria commented: “Since perpetrators of this crime are usually acting out of a profit motive, intent should not be a condition for liability to punishment.” See Australia, Belgium and Uruguay, who also took the position that no element of intent was necessary for Article 26. 1993 Yearbook Vol II, Part 1, p.68, para 30.
1995 The International Law Commission reduced the 12 crimes to 6. The draft code discussions moved to the Sixth Committee of the General Assembly (see: 12th – 25th and 44th meetings reports). At the GA Sixth Committee’s 12th Meeting held on 12 October 1995: “the Special Rapporteur on the topic had presented his thirteenth report recommending that only 6 of the 12 crimes identified in first reading for inclusion in the Code should be retained, namely… wilful and severe damage to the environment (article 26).” page 3, para 9. Records show concerns were raised, and reasons for retaining it included the fact that environmental harm is a state responsibility. 1995 Yearbook Vol II, Part 2, page 30, paras 119 – 121.
By the General Assembly Sixth Committee’s 16th meeting held on 17 October 1995, ‘wilful and severe damage to the environment’ was removed. Various countries including Chile did not agree. page 3, para 11. It was recorded that environmental crime during peace-time was removed from the 1996 Draft Code because the Special-Rapporteur wanted “to limit the list of crimes to be considered during the second reading to offences whose characterization as crimes against the peace and security of mankind was hard to challenge.”
1996 ‘wilful and severe damage to the environment’ (Article 26) is removed. The issue of environmental crime is tasked to a working-group in the ILC: “The Commission further decided that consultations would continue as regards [Article 26] …the Commission decided … to establish a working group that would meet … to examine the possibility of covering in the draft Code the issue of wilful and severe damage to the environment.” 1996 Yearbook Vol II, Part 2, p16, paras 40 & 41. In the same year, Canadian/Australian lawyer Mark Gray published his 1988 proposal for an international crime of ecocide, based on established international environmental and human rights law. He demonstrated that states, and arguably individuals and organisations, causing or permitting harm to the natural environment on a massive scale breach a duty of care owed to humanity in general. He proposed that such breaches, where deliberate, reckless or negligent, be identified as ecocide where they entail serious, and extensive or lasting, ecological damage; international consequences; and waste.
19 countries spoke out in the Legal Committee in favour of retaining damage to the environment on the list of crimes covered in the draft Code. In the same session Mr. Lukashuk objected: “at the fiftieth session of the General Assembly, the majority of Member States had come out in favour of characterizing “ecocide” as a crime, and only three States, France, Brazil and the Czech Republic were against it.” 1996 Yearbook, Vol 1, page 111, para 29.  But within weeks, the International Law Commission had also reduced the 6 crimes to 4 without vote. On 5 July, 1996, the final Draft Code of Crimes Against the Peace and Security of Mankind was adopted on second reading by the ILC. Ecocide was not reinstated and ‘wilful and severe damage to the environment’ had been removed, as was the section on State Responsibility.
(Article 19, ‘International Crimes of State’, of the draft Articles Articles on the Responsibility of States for Internationally Wrongful Acts is also removed. Article 19 read “an internationally wrongful act which results from the breach by a State of an international obligation so essential for the protection of fundamental interests of the international community that its breach is recognized as a crime by that community as a whole.”  )
1998 The final Draft Code of Crimes Against the Peace and Security of Mankind is renamed as the Rome Statute; ecocide has previously been excluded, and any mention of environmental harm is restricted to war-crime only, not a peace-crime. Under the Environmental Modification Convention 1977 (ENMOD) the test for war-time environmental destruction is ‘widespread, or long-term or severe’, whereas Article 8(2)(b) of the Rome Statute 1998 modified the ENMOD test with the change of one word to ‘widespread, long-term and severe.’ Under Article 8(2)(b) of the Rome Statute, environmental harm is a crime only in limited circumstances when “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.” Christian Tomuschat noted that this was done so that “only harm of exceptional circumstances shall be taken into account’”, despite objections.
2010 Polly Higgins proposes Ecocide law into the United Nations
2017 Public-facing campaign launched, see Stop Ecocide
 The Barcelona Traction case  ICJ Rep 3, page 33, paras 33 & 3
 UN Doc: A/CN.4/488 at 51 – 63 (objections by Austria, France, Ireland, Switzerland, UK and USA) and 137 (Germany) and for commentary see: http://legal.un.org/avl/ha/rsiwa/rsiwa.html. Also: Report of the ILC on the Work of its Fifty-third Session, UN GAOR, 56th Sess, Supp No 10, A/56/10
 Megret, Frederic. “The Case for a General International Crime Against the Environment” (2010).
 Falk, Richard A. “Environmental Warfare and Ecocide – Facts, Appraisal, and Proposals” In: Thee, Marek (ed.) Bulletin of Peace Proposals, Volume 1 (1973).
 known as The Ruhashyankiko Report.
 A/CN.4/SER.A/1978/Add.l (Part 2), Page 80, Article 19.2.(d). http://legal.un.org/docs/?path=../ilc/publications/yearbooks/english/ilc_1978_v2_p2.pdf&lang=EFS
 A/CN.4/SER.A/1987 http://legal.un.org/ilc/publications/yearbooks/english/ilc_1987_v1.pdf
 A/CN.4/SER.A/1993/Add.1 (Part 1) http://legal.un.org/ilc/publications/yearbooks/english/ilc_1993_v2_p1.pdf. See Netherlands: pp. 82-88; United Kingdom: pp. 97-102; United States of America: pp.102-105.
 A/CN.4/SER.A/1993/Add.1 (Part 2) http://legal.un.org/ilc/publications/yearbooks/english/ilc_1993_v2_p2.pdf
 A/CN.4/448 and Add.1 http://legal.un.org/ilc/publications/yearbooks/english/ilc_1993_v2_p1.pdf
 A/CN.4/SER.A/1996 Add.1 (Part 2) http://legal.un.org/docs/?path=../ilc/publications/yearbooks/english/ilc_1996_v2_p2.pdf&lang=EFSRAC
 Gray, Mark Allan. “The international crime of ecocide” California Western International Law Journal (1996) volume 26 page 215 et seq.; and “The international crime of ecocide” (2003) in International Crimes, The Library of Essays in International Law, ed. N Passas, Ashgate Publishing, Aldershot UK
 Tomuschat, Christian. 1996 Yearbook, volume II, page 24