International Humanitarian Law (“IHL“) is designed to mitigate the harms of armed conflicts, restricting means and methods of war to ensure the protection of civilians and persons who are no longer a direct part of hostilities. Born under an anthropocentric character, this branch of international law pursues respect of minimum standards of humanity during armed conflicts, establishing that belligerents must comply with humanitarian duties in all circumstances.
Notwithstanding, the human being is not the only victim of armed conflicts. The natural environment has long suffered from the means and methods of warfare as well. There are stories that go back to 1200 B.C. when the strategy of salting the land to make it infertile was used by the Assyrians, or during the French Revolution, when vast fields were burned, using large-scale fires as tools to obtain military advantages. Despite military techniques that embrace environmental degradation being not recent in our history, international rules and regulations concerned with the protection of the environment during armed conflicts have only emerged in the 20th century, especially after the world watched horrified the environmental atrocities committed during the Vietnam War (1954–1975).
The ecological destruction caused by the use of the toxic herbicide Agent Orange, the extensive deforestation, and chemical contamination during the Vietnam War led the international community to the development of the UN Convention on the Prohibition of Military or Any Other Hostile Use of the Environmental Modification Techniques (ENMOD), that prohibits the deliberate manipulation of natural processes that could produce “widespread, long-lasting or severe effects as the means of destruction, damage or injury to any other State Party” to this treaty. In the following year, the adoption of the Additional Protocol I to Geneva Conventions brought two articles (35 and 55) that secure specific protection of the environment during international armed conflicts (“IAC“).
Although the ENMOD Convention and articles 35 and 55 of Additional Protocol I concerning environmental conservation during armed conflicts have only emerged in the 1970s, general rules and principles of IHL also afford some kind of protection to the ecosystem in hostilities. The reason is the recognized civilian character of the natural environment. In this manner, parts of the environment that are not a military objective are “protected by the general principles and rules on the conduct of hostilities that protect civilian objects”, as the principle of distinction, proportionality, and precautions.
Additionally, rules on specific weapons may also have the capacity to afford protection, either directly or indirectly, to the environment. This post aims to examine the existing customary law and conventions on specific weapons that protect the natural environment in situations of armed conflicts.
Poison or Poisoned Weapons
The prohibition of the use of poison or poisoned weapons was first established in Article 70 of the 1863 Lieber Code, and Article 23 of both the 1899 and 1907 Hague Regulations, and was identified as customary law by the International Court of Justice’s Nuclear Weapons Advisory Opinion. The use of poison or poisoned weapons has also been recognized as a war crime in IAC under the International Criminal Court (“ICC“) Statute.
While the prohibition of the use of poison or poisoned weapons serves to protect human life, the way these means of warfare can be employed also has an impact on the environment. Depending on the substances used and how they are used, the poison can contaminate the ecosystem, causing long-lasting effects hard to control.
For example, the contamination of a river used as a source of drinking water for a certain community can affect not only people who depend on that river but all flora and fauna that rely on this water source. This was exactly what happened to the Iraqi town of Snune in northern Sinjar, in 2014. After the ISIS invasion, besides the seized and murdered local men, women, and children, the jihadists poisoned practically every well they could find. In the Snune’s south villages, the group blocked scores of wells with rocks and rubble. “In doing so, it reduced a lush agricultural district to a parched wasteland of swirling dust and bare fields”. By the time the extremists left, there was scarcely a functioning water outlet, which directly affects the subsistence of the surviving population. The same illegal strategy of poisoning water was used against the civilian population in Mosul, also in 2014.
Therefore, poison and poisoned weapons can also affect human life by damaging elements from the natural system, as drinking-water sources, agriculture, livestock, and render whole areas uninhabitable. Consequently, prohibiting the use of these weapons may contribute to the protection of the environment during hostilities.
Biological and Chemical Weapons
The use of biological weapons is forbidden in IAC under the 1925 Geneva Gas Protocol and under the 1972 Biological Weapons Convention applicable both in IACs and non-international armed conflicts (“NIAC“). This rule is also recognized as customary international law applicable in both IACs and NIACs.
However, it is not only the use of biological weapons that can affect the ecosystem but the destruction or disposal of such weapons as well. This is why Article 2 of the Biological Weapons Convention provides that each State party must “destroy, or to divert into a peaceful purpose, its biological weapons, taking all the necessary safety precautions “to protect populations and the environment”.
Conversely, the prohibition of using chemical weapons is an established norm of customary international law, applicable in both IAC and NIACs. This prohibition is also presented in the 1899 Hague Declaration concerning Asphyxiating Gases, the 1925 Geneva Gas Protocol, and the 1993 Chemical Weapons Convention. For IAC, the use of chemical weapons has been identified as a war crime under the 1998 ICC Statute.
The effects of biological and chemical weapons on the environment were analyzed by the 1969 UN Report of the Secretary-General on Chemical and Bacteriological (Biological) Weapons and the Effects of their Possible Use. The polluting of the water supplies and poisoning the soil are some of the long-term effects caused by chemical weapons pointed out by the UN. Concerning bacteriological weapons, the report stated that they can affect sources of food through the spread of plant diseases, animal diseases, and even introduce a new epidemic or reintroduce an old one.
Likewise, the link between environmental destruction caused by these weapons and human health was already observed by the World Health Organization (“WHO“) in the 1970 Report on health aspects of chemical and biological weapons. According to WHO, new foci of diseases can result from the chemical or biological warfare since “extensive damage to the flora over large areas may create conditions favoring the establishment of new vectors or reservoirs of disease infective to man”.
IHL rules that ban the use of chemical and biological weapons serve to protect human life and the environment since these weapons are capable of causing long-lasting effects on flora and fauna of sites affected by the conduct of military operations.
“If incendiary weapons are used, particular care must be taken to avoid, and in any event to minimize, incidental loss of civilian life, injury to civilians and damage to civilian objects, including the natural environment”. This is a rule established as a norm of customary law applicable in both IACs and NIACs. With an express reference to the natural environment, this rule obliges the states and armed groups to take special precautions when using incendiary weapons.
For states parties to the 1980 Protocol III to the Convention on Certain Conventional Weapons, it is “prohibited to make forests or other kinds of plant cover the object of attack by incendiary weapons except when such natural elements are used to cover, conceal or camouflage combatants or other military objectives, or are themselves military objectives”. The special protection afforded by these rules is due to the indiscriminate effects of these weapons since if incendiaries spread, they may become uncontrollable, and they can bring indiscriminate destruction, especially to the ecosystem. The harm to the natural environment can cause unpredictable long-term consequences and, consequently, affect human life and subsistence.
As stated by the UN Secretary-General in a 1972 Report on napalm and other incendiary weapons, “attempts have been made to use incendiaries to damage crops, forests, and other features of the natural environment”. Although the effects of these armaments are not entirely acknowledged, these “attempts may lead to irreversible ecological changes”, having long-standing results different from what was originally expected.
In this way, the use of incendiary weapons for non-states parties to the Protocol III to the Convention on Certain Conventional Weapons should be based on a balance between considerations of military necessity and the damage, including the one against the natural environment, to prevent the unpredictable and long-term ecological consequences of these weapons.
The use of landmines can impact the natural environment as well. Once these munitions are laid in the ground, they affect the ecological balance, having effects on the vegetation, fauna, and soil structure. These munitions also introduce poisonous substances to the ground, which affect the use of the land and, consequentially, affect the means of income of the population.
As examples of environmental degradation caused by landmines, one can cite the gazelles’ disappearance from places mined during the Second World War in North Africa, according to the UN Report of the Secretary-General on problems of remnants of war. The report also drew attention to the marine environment, as these munitions disposed at sea can release toxic properties of their chemical components.
The use of anti-personnel mines is prohibited for states parties to the Anti-Personnel Mine Ban Convention, in both IACs and NIACs. Each state has an obligation to destroy or ensure the destruction of its anti-personnel mine stockpiles.
For non-states parties to the Anti-Personnel Mine Ban Convention, but parties to Protocol II to the Convention on Certain Conventional Weapons (“Protocol II”), the use of anti-personnel and anti-vehicle mines is restricted by the general and specific rules of the Protocol II. According to this convention, the states parties need to record all information on the placement of mines, and after the termination of hostilities, all minefields must be cleared, and mines must be removed, destroyed, or maintained in accordance with the requirements of Protocol II.
In the case of non-states parties to any convention cited above, the minimum customary law rules that apply specifically to these weapons determine that “when landmines are used, particular care must be taken to minimize their indiscriminate effects, including those on the natural environment”. The parties to the conflict must record their placement, and, at the end of hostilities, they must remove or render them harmless.
The impact of certain weapons can degrade the environment during armed conflicts, affecting the water, soil, livestock, plants, and animals indispensable for human life.
As IHL rules are based on a balance between considerations of military necessity and humanity, there are conventions and customary rules that prohibit or limit the use of particular weapons, such as poisoned weapons, biological and chemical weapons, incendiary weapons, and landmines, that may cause ecological consequences that affect human survival and subsistence. From a long-term viewpoint, “no civilian population can be adequately protected against the effects of war if the natural environment it depends on for its sustenance is destroyed, poisoned or severely damaged by military operations”.
The environmental protection brought by these customary laws and conventions is also in line with the requirements of ecological equilibrium and social sustainability, subjects so important nowadays.
While IHL affording specific protection to the environment in situations of armed conflicts must continue developing, the efforts to implement and strengthen the existing IHL rules are important as well. This is why it is essential to educate and strengthen knowledge of IHL among academics, belligerents, staff of governmental and non-governmental organizations, and the international community.
The environment cannot remain a silent victim of warfare.
Idovel Danielle Ribeiro Guides holds a Master of Science in Conflict Management and Resolution from the University of San Diego, a Bachelor of Laws and a Postgraduate degree in Human Rights and Social Issues from Pontifícia Universidade Católica do Paraná. She worked as a Legal Advisor inside the Paraná State Court House of Appeals in Brazil for over 10 years. Recently, she joined the Red Cross IHL team in Brazil to help promote International Humanitarian Law.
 Bouvier, A. (1991), Protection of the natural environment in time of armed conflict, International Review of the Red Cross, Vol. 31, p. 571.
 Geneva Conventions I–IV, common Art. 1.
 Ventura, V. A. M. F (2013) Ecologização do Direito Internacional Humanitário: perspectivas para maior efetividade da proteção ambiental durante conflitos armados. João Pessoa, p. 9.
 Mrema, E., Bruch, C.E., and Diamond, J. (2009) Protecting the environment during armed conflict: an inventory and analysis of international law. UNEP/Earthprint, p. 8.
 UN Convention on the Prohibition of Military or Any Other Hostile Use of the Environmental Modification Techniques (ENMOD), Article 1.
 Bouvier, A. (1991), Protection of the natural environment in time of armed conflict, International Review of the Red Cross, Vol. 31, p. 571.
 ICRC (2020), Guidelines on the Protection of the Natural Environment: Rules and recommendations relating to the protection of the natural environment under international humanitarian law with commentary (ICRC, Geneva), p. 18
 Ibid, p. 46.
 Ibid, p. 19.
 ICRC, Customary IHL Database. Rule 72 and commentary. Available at: <https://ihl-databases.icrc.org/customary-ihl/eng/docs/v2_rul_rule72>.
 ICJ, Legality of the Threat or Use of Nuclear Weapons, Advisory Opinion, 8 July 1996, paras 80–82.
 ICC Statute, Article 8 (2)(b).
 ICRC (2020), Guidelines on the Protection of the Natural Environment: Rules and recommendations relating to the protection of the natural environment under international humanitarian law with commentary (ICRC, Geneva), p. 86.
 Schwartzstein, P. (2019), The History of Poisoning the Well. From ancient Mesopotamia to modern-day Iraq, the threat to a region’s water supply is the cruelest cut of all. Available at: <https://www.smithsonianmag.com/history/history-well-poisoning-180971471/> [Accessed 30 September 2020].
 Ibid, para. 3.
 BBC News. 2021. Mosul diaries: Poisoned by water. Available at: https://www.bbc.com/news/world-middle-east-29600573 [Accessed 28 March 2021].
 ICRC, Customary IHL Database. Rule 73 and commentary. Available at: <https://ihl-databases.icrc.org/customary-ihl/eng/docs/v1_rul_rule73>.
 Biological Weapons Convention, Article 2.
 ICRC, Customary IHL Database. Rule 74 and commentary. Available at: <https://ihl-databases.icrc.org/customary-ihl/eng/docs/v1_rul_rule74> .
 ICC Statute, Art. 8(2)(b)(xviii) and (e)(xiv).
 UN Report of the Secretary-General on Chemical and Bacteriological (Biological) Weapons and the Effects of their Possible Use, UN Doc. A/7575/Rev.1 and S/9292/, p.71
 World Health Organization. Health Aspects of Chemical and Biological Weapons, 1st ed.; WHO: Geneva, 1970. Available at: <http://www.who.int/csr/delibepidemics/biochem1stenglish/en/>.
 Ibid, p. 16.
 ICRC, Customary IHL Database. Rule 84 and commentary. Available at: <https://ihl-databases.icrc.org/customary-ihl/eng/docs/v1_rul_rule84>.
 Protocol III to the Convention on Certain Conventional Weapons, Article 2.
 UN General Assembly, Report of the Secretary-General on napalm and other incendiary weapons and all aspects of their possible use. UN Doc. A/8803, 9 October 1972, p. 51.
 Berhe, A. A. (2000) Landmines and land degradation: a regional political ecology perspective on the impacts of landmines on environment and development in the developing world. Michigan State University, East Lansing, Michigan, USA.
 UN General Assembly, Problems of remnants of war: Report of the Secretary-General, UN Doc. A/38/383, 19 October 1983, p.11.
 Ibid, p. 12.
 Anti-Personnel Mine Ban Convention, Article 1(2).
 Protocol II to the Convention on Certain Conventional Weapons, Article 9.
 Ibid, Article 10.
 ICRC, Customary IHL Database. Rule 81 and commentary.
 Melzer, Nils. International Humanitarian Law: A Comprehensive Introduction. Geneva: International Committee of the Red Cross, 2016, p. 96.