The States Parties to this Convention,
Guided by the interest of consolidating peace, and wishing to contribute to the cause of halting
the arms race, and of bringing about general and complete disarmament under strict and
effective international control, and of saving mankind from the danger of using new means of
Determined to continue negotiations with a view to achieving effective progress toward further
measures in the field of disarmament,
Recognizing that scientific and technical advances may open new possibilities with respect to
modification of the environment,
Recalling the Declaration of the United Nations Conference on the Human Environment,
adopted at Stockholm on 16 June 1972,
Realizing that the use of environmental modification techniques for peaceful purposes could
improve the interrelationship of man and nature and contribute to the preservation and
improvement of the environment for the benefit of present and future generations,
Recognizing, however, that military or any other hostile use of such techniques could have
effects extremely harmful to human welfare,
Desiring to prohibit effectively military or any other hostile use of environmental modification
techniques in order to eliminate the dangers to mankind from such use, and affirming their
willingness to work towards the achievement of this objective,
Desiring also to contribute to the strengthening of trust among nations and to the further
improvement of the international situation in accordance with the purposes and principles of the
Charter of the United Nations,
Have agreed as follows:
1. Each State Party to this Convention undertakes not to engage in military or any other hostile
use of environmental modification techniques having widespread, longlasting or severe effects
as the means of destruction, damage or injury to any other State Party.
2. Each State Party to this Convention undertakes not to assist, encourage or induce any State,
group of States or international organization to engage in activities contrary to the provisions of
paragraph 1 of this article.
As used in article I, the term “environmental modification techniques” refers to any technique for
changing – through the deliberate manipulation of natural processes – the dynamics, composition
or structure of the Earth, including its biota, lithosphere, hydrosphere and atmosphere, or of
1. The provisions of this Convention shall not hinder the use of environmental modification
techniques for peaceful purposes and shall be without prejudice to the generally recognized
principles and applicable rules of international law concerning such use.
2. The States Parties to this Convention undertake to facilitate, and have the right to participate
in, the fullest possible exchange of scientific and technological information on the use of
environmental modification techniques for peaceful purposes. States Parties in a position to do
so shall contribute, alone or together with other States or international organizations, to
international economic and scientific co-operation in the preservation, improvement and
peaceful utilization of the environment, with due consideration for the needs of the developing
areas of the world.
Each State Party to this Convention undertakes to take any measures it considers necessary in
accordance with its constitutional processes to prohibit and prevent any activity in violation of the
provisions of the Convention anywhere under its jurisdiction or control.
1. The States Parties to this Convention 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. Consultation and co-operation pursuant to this article may also be
undertaken through appropriate international procedures within the framework of the United
Nations and in accordance with its Charter. These international procedures may include the
services of appropriate international organizations, as well as of a Consultative Committee of
Experts as provided for in paragraph 2 of this article.
2. For the purposes set forth in paragraph 1 of this article, the Depositary shall, within one month
of the receipt of a request from any State Party to this Convention, convene a Consultative
Committee of Experts. Any State Party may appoint an expert to the Committee whose functions
and rules of procedure are set out in the annex, which constitutes an integral part of this
Convention. The Committee shall transmit to the Depositary a summary of its findings of fact,
incorporating all views and information presented to the Committee during its proceedings, The
Depositary shall distribute the summary to all States Parties.
3. Any State Party to this Convention which has reason to believe that any other State Party is
acting in breach of obligations deriving from the provisions of the Convention may lodge a
complaint with the Security Council of the United Nations. Such a complaint should include all
relevant information as well as all possible evidence supporting its validity.
4. Each State Party to this Convention undertakes to cooperate in carrying out any investigation
which the Security Council may initiate, in accordance with the provisions of the Charter of the
United Nations, on the basis of the complaint received by the Council. The Security Council shall
inform the States Parties of the results of the investigation.
5. Each State Party to this Convention undertakes to provide or support assistance, in
accordance with the provisions of the Charter of the United Nations, to any State Party which so
requests, if the Security Council decides that such party has been harmed or is likely to be
harmed as a result of violation of the Convention.
1. Any State Party to this Convention may propose amendments to the Convention. The text of
any proposed amendment shall be submitted to the Depositary, who shall promptly circulate it to
all States Parties.
2. An amendment shall enter into force for all States Parties to this Convention which have
accepted it, upon the deposit with the Depositary of instruments of acceptance by a majority of
States Parties. Thereafter it shall enter into force for any remaining State Party on the date of
deposit of its instrument of acceptance.
This Convention shall be of unlimited duration.
1. Five years after the entry into force of this Convention, a conference of the States Parties to
the Convention shall be convened by the Depositary at Geneva, Switzerland. The conference
shall review the operation of the Convention with a view to ensuring that its purposes and
provisions are being realized, and shall in particular examine the effectiveness of the provisions
of paragraph 1 of article I in eliminating the dangers of military or any other hostile use of
environmental modification techniques.
2. At intervals of not less than five years thereafter, a majority of the States Parties to this
Convention may obtain, by submitting a proposal to this effect to the Depositary, the convening
of a conference with the same objectives.
3. If no conference has been convened pursuant to paragraph 2 of this article within ten years
following the conclusion of a previous conference, the Depositary shall solicit the views of all
States Parties to this Convention concerning the convening of such a conference. If one third or
ten of the States Parties, whichever number is less, respond affirmatively, the Depositary shall
take immediate steps to convene the conference.
1. This Convention shall be open to all States for signature. Any State which does not sign the
Convention before its entry into force in accordance with paragraph 3 of this article may accede
to it at any time.
2. This Convention shall be subject to ratification by signatory States. Instruments of ratification
or accession shall be deposited with the Secretary-General of the United Nations.
3. This Convention shall enter into force upon the deposit of instruments of ratification by twenty
Governments of accordance with paragraph 2 of this article.
4. For those States whose instruments of ratification or accession are deposited after the entry
into force of this Convention, it shall enter into force on the date of the deposit of their
instruments of ratification or accession.
5. The Depositary shall promptly inform all signatory and acceding States of the date of each
signature, the date of deposit of each instrument of ratification or accession and the date of the
entry into force of this Convention and of any amendments thereto, as well as the receipt of
6. This Convention shall be registered by the Depositary in accordance with Aricle 102 of the
Charter of the United Nations.
This Convention, of which the Arabic, Chinese, English, French, Russian and Spanish texts are
equally authentic, shall be deposited with the Secretary-General of the United Nations, who shall
send duly certified copies thereof to the Governments of the signatory and acceding States.
IN WITNESS WHEREOF, the undersigned, being duly authorized thereto, have signed this
Done at Geneva, on the 18 day of May 1977
Annex to the Convention
Consultative Committee of Experts
1. The Consultative Committee of Experts shall undertake to make appropriate findings of fact
and provide expert views relevant to any problem raised pursuant to paragraph 1 of article V of
this Convention by the State Party requesting the convening of the Committee.
2. The work of the Consultative Committee of Experts shall be organized in such a way as to
permit it to perform the functions set forth in paragraph 1 of this annex. The Committee shall
decide procedural questions relative to the organization of its work, where possible by
consensus, but otherwise by a majority of those present and voting. There shall be no voting on
matters of substance.
3. The Depositary or his representative shall serve as the Chairman of the Committee.
4. Each expert may be assisted at meetings by one or more advisers.
5. Each expert shall have the right, through the Chairman, to request from States, and from
international organizations, such information and assistance as the expert considers desirable
for the accomplishment of the Committee’s work.
Understandings regarding the Convention
It is the understanding of the Committee that, for the purposes of this Convention, the terms
“long-lasting” and “severe” shall be interpreted as follows:
a) “widespread”: encompassing an area on the scale of several hundred square kilometres;
b)”long-lasting”: lasting for a period of months, or approximately a season;
c) “severe”: involving serious or significant disruption or harm to human life, natural and
economic resources or other assets.
It is further understood that the interpretation set forth above is intended exclusively for this
Convention and is not intended to prejudice the interpretation of the same or similar terms if
used in connexion with any other international agreement.
Understanding relating to article II
It is the understanding of the Committee that the following examples are illustrative of
phenomena that could be caused by the use of environmental modification techniques as
defined in article II of the Convention: earthquakes; tsunamis; an upset in the ecological balance
of a region; changes in weather patterns (clouds, precipitation, cyclones of various types and
tornadic storms); changes in climate patterns; changes in ocean currents; changes in the state
of the ozone layer; and changes in the state of the ionosphere.
It is further understood that all the phenomena listed above, when produced by a military or any
other hostile use of environmental modification techiques, would result, or could reasonably be
expected to result, in widespread, long-lasting or severe destruction, damage or injury. Thus,
military or any other hostile use of environmental modification techniques as defined in article II,
so as to cause those phenomena as a means of destruction, damage or injury to another State
Party, would be prohibited.
It is recognized, moreover, that the list of examples set out above is not exhaustive. Other
phenomena which could result from the use of environmental modification techniques as
defined in article II could also be appropriately included. The absence of such phenomena from
the list does not in any way imply that the undertaking contained in article I would not be
applicable to those phenomena, provided the criteria set out in that article were met.
Understanding relating to article III
It is the understanding of the Committee that this Convention does not deal with the question
whether or not a given use of environmental modification techniques for peaceful purposes is in
accordance with generally recognized principles and applicable rules of international law.
Understanding relating to article VIII
It is the understanding of the Committee that a proposal to amend the Convention may also be
considered at any conference of Parties held pursuant to article VIII. It is further understood that
any proposed amendment that is intended for such consideration should, if possible, be
submitted to the Depositary no less than 90 days before the commencement of the conference.
Note: These Understandings are not incorporated into the Convention but are part of the negotiating
record and were included in the report transmitted by the Conference of the Committee on Disarmament
to the United Nations General Assembly in September 1976 (Report of the Conference of the Committee
on Disarmament, Volume I, General Assembly Official records: Thirty-first session, Supplement No. 27
(A/31/27), New York, United Nations, 1976, pp. 91-92).