The list of parties to the Environmental Modification Convention encompasses the states who have signed and ratified or acceded to the international agreement prohibiting military use of environmental modification

Weather control

Weather control is the act of manipulating or altering certain aspects of the environment to produce desirable changes in weather. Weather control can have the goal of preventing damaging weather, such as hurricanes or tornadoes, from occurring; of causing beneficial weather, such as rainfall in...

 techniques.

On May 18, 1977, the Environmental Modification Convention (ENMOD) was opened for signature. North Yemen

North Yemen

North Yemen is a term currently used to designate the Yemen Arab Republic , its predecessor, the Mutawakkilite Kingdom of Yemen , and their predecessors that exercised sovereignty over the territory that is now the north-western part of the state of Yemen in southern Arabia.Neither state ever...

 became the first state to deposit the treaty on 20 July 1977. The treaty came into force

Coming into force

Coming into force or entry into force refers to the process by which legislation, regulations, treaties and other legal instruments come to have legal force and effect...

 and closed for signature on October 5, 1978. Since then, states that did not sign the treaty can now only accede to it. The instrument of ratification, accession, or succession is deposited with the Secretary-General of the United Nations

As of 2008, 75 states have ratified or acceded to the treaty, most recently Nicaragua

Nicaragua

Nicaragua is the largest country in the Central American American isthmus, bordered by Honduras to the north and Costa Rica to the south. The country is situated between 11 and 14 degrees north of the Equator in the Northern Hemisphere, which places it entirely within the tropics. The Pacific Ocean...

on September 6, 2007. A further 17 states have signed but not ratified the treaty.

Ratified or acceded states

State	Signed	Ratified	Method
Afghanistan			Accession
Algeria			Accession
Antigua and Barbuda			Succession from  United Kingdom
Argentina			Accession
Armenia			Accession
Australia			Ratification
Austria			Accession
Bangladesh			Accession
Belarus			Ratification as  Byelorussian SSR
Belgium			Ratification
Benin			Ratification
Brazil			Ratification
Brunei		None	Succession from  United Kingdom
Kingdom of Bulgaria			Ratification
Canada			Ratification
Cape Verde			Accession
Chile			Accession
Mainland China			Accession
Costa Rica			Accession
Cuba			Ratification
Cyprus			Ratification
Czech Republic			Succession from  Czechoslovakia Signed 18 May 1977 Ratified 12 May 1978
Denmark			Ratification
Dominica			Succession from  United Kingdom
Egypt			Accession?
Finland			Ratification
Germany			Ratification as  West Germany Also  German Democratic Republic Signed 18 May 1977 Ratified 25 May 1978
Ghana			Ratification
Greece			Accession
Guatemala			Accession
Hungary			Ratification
India	?		Ratification
Republic of Ireland			Ratification
Italy			Ratification
Japan			Accession
Kazakhstan			Accession
Kuwait			Accession
Laos			Ratification
Lithuania			Accession
Malawi			Accession
Mauritius			Accession
Mongolia			Ratification
Netherlands			Ratification
New Zealand			Accession, includes  Cook Islands and  Niue
Nicaragua			Ratification
Niger			Accession
North Korea			Accession
Norway			Ratification
Pakistan			Accession
Panama			Accession
Papua New Guinea			Accession
Poland			Ratification
Kingdom of Romania			Ratification
Russia			Ratification as  Soviet Union
Saint Kitts and Nevis		None	Succession from  United Kingdom
Saint Lucia			Succession from  United Kingdom
Saint Vincent and the Grenadines			Succession from  United Kingdom
São Tomé and Príncipe			Accession
Slovakia			Succession from  Czechoslovakia Signed 18 May 1977 Ratified 12 May 1978
Slovenia			Accession
Solomon Islands			Succession from  United Kingdom
South Korea			Accession
Spain			Ratification
Sri Lanka			Ratification
Sweden			Accession
Switzerland			Accession
Tajikistan			Accession
Tunisia			Ratification
Ukraine			Ratification as  Ukrainian SSR
United Kingdom			Ratification
United States			Ratification
Uruguay			Accession
Uzbekistan			Accession
Vietnam			Accession
Yemen			Ratification as  Yemen Arab Republic Also  South Yemen Acceded 12 June 1979

States that have signed but not ratified

State	Signed
Bolivia
Cambodia
Democratic Republic of the Congo Signed as  Zaire
Ethiopia
Holy See
Iceland
Iran
Iraq
Lebanon
Liberia
Luxembourg
Morocco
Portugal
Sierra Leone
Syria
Turkey
Uganda