The Convention on the Prohibition of Military or Any Other Hostile Use of Environmental Modification Techniques entered into force on 5 October 1978, in accordance with its article IX.

Preparatory work on the Convention was conducted at the Conference of the Committee on Disarmament (CCD) in 1974, following a joint proposal of the United States of America and the Union of Soviet Socialist Republics,. A draft convention, prepared by a Working Group set up within the CCD, was submitted, in 1976, to the General Assembly. In that same year, the First Committee of the General Assembly decided to send the text of the draft Convention to the General Assembly, which adopted resolution 31/72 on 10 December 1976, with the text of the Convention attached as an annex thereto. The Convention was opened for signature and ratification on 18 May 1977.

The Convention consists of ten articles which, inter alia, prohibit the States Parties from engaging 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 (article I), and require States Parties to undertake to consult one another and to co-operate in solving any problems which may arise in relation to the objectives of, or in the application of the provisions of, the Convention (article V, paragraph 1).

The issue of the artificial modification of the environment for military or other hostile purposes began to attract increasing international attention following the United Nations Conference on the Human Environment, held at Stockholm, in 1972. The Declaration adopted by that Conference stated, inter alia, that nations had the responsibility of ensuring that their activities did not damage the environment of other nations (A/CONF.48/14/Rev.1, Chapter 1).

Following from this, a decision was taken at the meeting between the Union of Soviet Socialist Republics (USSR) and the United States of America (USA) held in Moscow, between 27 June and 3 July 1974, to advocate the most effective measures possible designed to overcome the dangers of the use of environmental modification techniques for military purposes (S/11428). This joint decision, together with an associated USSR-USA statement (Annex IV, A/9698), was raised during the 1974 Conference of the Committee on Disarmament (CCD), which ran from 16 April to 22 August, in association with a discussion on whether the CCD should study the question of prohibiting weather manipulation for military purposes (A/9627).

By a letter of 7 August 1974 to the Secretary-General, the USSR requested the inclusion in the agenda of the twenty-ninth session of the General Assembly of an item entitled “Prohibition of action to influence the environment and climate for military and other purposes incompatible with the maintenance of international security, human well-being and health” (A/9702). This item was allocated to the First Committee of the General Assembly (A/9910).

On 24 September 1974 the USSR submitted a draft resolution to the First Committee, with a draft convention on the topic attached as an annex (A/C.1/L.675). On the recommendation of its First Committee, the General Assembly adopted resolution 3264 (XXIX) on 9 December 1974. The Assembly expressed the need, inter alia, to adopt, through the conclusion of an international convention, effective measures to prohibit action to influence the environment and climate for military and other hostile purposes which were incompatible with the maintenance of international security, human well-being and health. The Assembly also took note of the draft convention submitted by the USSR, as well as other views and suggestions put forward, and requested the CCD to proceed as soon as possible to achieve agreement on the text of a convention and to submit a report to the Assembly at its thirtieth session.

The CCD held informal meetings on environmental warfare, which took place in Geneva from 4 March to 28 August 1975, with the participation of experts from a number of CCD member States and observers from the United Nations Environment Programme and the World Meteorological Organization. On 21 August, the USSR and the USA submitted to the CCD identical draft conventions on the prohibition of military and any other hostile use of environmental modification techniques, expressing the hope that an early agreement could be reached. Due to a lack of time, the CCD did not hold substantive discussions on the drafts (Report of the Conference of Committee on Disarmament to the General Assembly (4 March to 28 August 1975), A/10027).

At the thirtieth session of the General Assembly, in 1975, the First Committee focused its discussions on this topic on the draft conventions submitted to the CCD (Report of the First Committee to the General Assembly, A/10444). On the recommendation of the First Committee, the General Assembly adopted resolution 3475 (XXX) on 11 December 1975, by which it noted the identical draft conventions submitted by USSR and USA, and requested, inter alia,the CCD to continue negotiations with a view to reaching early agreement on a convention text during the CCD’s 1976 session, if possible. It also asked the CCD to submit a report to the Assembly on the results achieved for consideration at the Assembly’s thirty-first session.

At its 1976 session, held from 17 February to 22 April, the CCD continued to negotiate for an early agreement on the prohibition of environmental warfare. It established an ad hoc working group to consider modifications to the identical draft convention texts and to facilitate negotiation of an agreed text. The Working Group on the Prohibition of Military or Any Other Hostile Use of Environmental Modification Techniques held twenty-nine meetings between 2 July and 1 September 1976, attended by all CCD members present at the 1976 session. During the Working Group, several modifications to the text of the convention were agreed upon. However, no agreement could be reached on other proposed modifications and the Working Group reported on the dissenting views of some members. As consensus on the draft convention was not possible, the CCD transmitted to the General Assembly, as an annex to its report, the report of the Working Group containing the text of the draft convention as well as related comments, dissenting views and reservations (A/31/27 [Vols. I and II]).

At the thirty-first session of the General Assembly, in 1976, the item was considered in a working group of the First Committee. During debate of the First Committee, significant differences in viewpoint emerged, as they had in the CCD, which resulted in the submission of a number of differing draft resolutions and revisions. The main point of contention concerned whether the process of negotiation at the CCD should continue or whether sufficient consensus existed for submission of the draft convention to the General Assembly. The First Committee eventually voted to recommend the draft convention to the General Assembly for its adoption (Report of the First Committee to the General Assembly, A/31/382). On the recommendation of its First Committee, the General Assembly adopted resolution 31/72 on 10 December 1976, with the text of the Convention on the Prohibition of Military or Any Other Hostile Use of Environmental Modification Techniques attached as an annex thereto.

The Convention was opened for signature and ratification on 18 May 1977. The Convention entered into force on 5 October 1978, in accordance with its article IX, paragraph 3.

Declaration of the United Nations Conference on the Human Environment, Report of the United Nations Conference on the Human Environment, Stockholm, 5-16 June 1972 (A/CONF.48/14Rev.1), Chapter I

Letter dated 8 August 1974 from the United States of America and the Union of Soviet Socialist Republics addressed to the Secretary-General (S/11428)

Letter dated 8 August 1974 from the Union of Soviet Socialist Republics and the United States of America to the United Nations addressed to the Secretary-General (A/9698) (Annex IV: Joint Statement by United States and USSR on Most Effective Measures Possible to Overcome Dangers of Use of Environmental Modification Techniques for Military Purposes)

Report of the Conference of Committee on Disarmament to the General Assembly (16 April – 22 August 1974), (Annex I: Documents issued by CCD; Annex II: Documents of CCD annexed to report: Annex III: List of Verbatim records of meetings of CCD) (A/9627 - A/9708-DC/237)

Letter from the USSR addressed to the Secretary General (request for inclusion in agenda of item entitled: ‘Prohibition of action to influence the environment and climate for military and other purposes incompatible with the maintenance of international security, human well-being and health’) (A/9702 and Corr.1, 7 August 1974)

First Committee of the General Assembly, draft resolution on the Prohibition of action to influence the environment and climate for military and other purposes incompatible with the maintenance of international security, human well-being and health, submitted by Union of Soviet Socialist Republics (A/C.1/L.675 and Rev.1, 24 September and 22 November 1974)

First Committee of the General Assembly, Verbatim records of meetings Nos.1998 to 2008, 2010 to 2016, 2018, 2019, and 2026 to 2028, held on 21, 24, 25, 28 to 31 October, 4 to 8, 11, 13, 14, 21 and 22 November 1974 (A/C.1/PV.1998-2008, 2010-2016, 2018, 2019, 2026, 2028)

Report of the First Committee to the General Assembly (A/9910, 6 December 1974)

General Assembly verbatim records of plenary meeting No. 2309 held on 9 December 1974 (A/PV.2309)

General Assembly resolution 3264 (XXIX) of 9 December 1974 (Prohibition of action to influence the environment and climate for military and other purposes incompatible with the maintenance of international security, human well-being and health)

Report of the Conference of Committee on Disarmament to the General Assembly (4 March to 28 August 1975), (Chapter III: Report on question of comprehensive test ban agreement, Annex A: List of working papers and other documents, Annex B: Tests of working papers and other Committee documents, Annex C: List of verbatim records) (A/10027-DC/238)

Letter from Mexico to the First Committee, Working paper on scope of prohibition of military or any other hostile use of environmental modification techniques (A/C.1/31/8, 15 November 1975)

First Committee of the General Assembly, Verbatim records of meetings Nos. 2073, 2074, 2078, 2082, 2087 to 2090, 2102 and 2108, held on 30 to 31 October, 6, 10, 14, 17 and 18 November, 2 and 5 December 1975 (A/C.1/PV.2073, 2074, 2078, 2082, 2087-2090, 2012, 2108)

Report of the First Committee to the General Assembly (A/10444, 10 December 1975)

General Assembly verbatim records of plenary meeting No. 2437 held on 11 December 1975 (A/PV.2437)

General Assembly draft resolution (A/C.1/L739 and Rev.1, 28 November and 5 December 1975)

General Assembly resolution 3475 (XXX) of 11 December 1975 (Prohibition of action to influence the environment and climate for military and other purposes incompatible with the maintenance of international security, human well-being and health)

Report of the Conference of Committee on Disarmament to the General Assembly (17 February to 3 September 1976) Vol. I (Chapter III: Special report on question of Convention to Prohibit Environmental Warfare, Annex I: Report of Working Group on Prohibition of Military or Any Other Hostile Use of Environmental Modification Techniques 2 July to 1 September 1976, Annex II: Documents issued by CCD, Annex IV: List of verbatim records of meetings of CCD, Annex V: Index by subject and country of statements made in CCD in 1976), Vol. II (Annex III: Documents of CCD annexed to report) (A/31/27[Vol.I] and A/31/27[Vol.II])

General Assembly draft resolution (A/C.1/31/L.4 and Rev.1, 3 November and 2 December 1976)

General Assembly, draft resolution (A/C.1/31/L.5, 4 November 1976)

General Assembly, revised draft resolution annexing draft Convention on prohibition of military or any other hostile use of environmental modification techniques (A/C.1/31/L.5/Rev.1, Rev.2 and Rev.2/Corr.1, 10, 29 and 30 November 1976)

General Assembly, revised draft resolution annexing draft convention on prohibition of military or any other hostile use of environmental modification techniques (A/C.1/31/L.5/Rev.3, 2 December 1976)

First Committee of the General Assembly, Verbatim records of meetings Nos.20, 21, 24 to 26, 28, 30, 31, 34 to 36, 38, 39, 50 and 51, held on 1, 2, 5, 8 to 12, 16, 17, 19 November, 2 and 3 December 1976, respectively (A/C.1/31/PV.20, 21, 24-26, 28, 30, 31, 34-36, 38, 39, 50, 51)

Report of the First Committee to the General Assembly (A/31/382, 9 December 1976)

General Assembly, Verbatim records of plenary meeting No. 96 held on 10 December 1976 (A/31/PV.96)

General Assembly resolution 31/72 of 10 December 1976 (Convention on the Prohibition of Military or Any Other Hostile Use of Environmental Modification Techniques)