Military operations by the United States and Israel against Iran have triggered a crisis that extends beyond the battlefield. Fires at refineries, oil spills in the Persian Gulf, massive emissions of polluting gases, and chemical and nuclear risks paint a picture that threatens the health of millions of people and could leave ecological scars for decades, both in the Middle East and in distant regions of the planet.
Modern warfare is no longer measured solely in terms of destroyed cities or displaced populations. In the Persian Gulf, since the attacks began on 28 February, the conflict has triggered a process of large-scale environmental degradation whose magnitude is only just beginning to be understood. Fires at refineries, explosions at fuel depots and attacks on oil tankers have released a combination of toxic substances that are spreading through the atmosphere, soil and sea, affecting extremely sensitive ecosystems and densely populated urban areas.
Environmental impact
In just the first few weeks of fighting, emissions from industrial fires and explosions have released around five million tonnes of carbon dioxide, a volume exceeding the annual emissions of some small countries. This phenomenon is explained by the fact that the destruction of energy facilities—refineries, oil depots and gas plants—causes the massive combustion of hydrocarbons and the release of greenhouse gases that accelerate global warming. Added to this is the release of fine particles, black carbon and toxic compounds that immediately affect air quality and public health.
The most visible manifestation of this impact has been witnessed in Tehran. Following attacks on oil facilities on the outskirts of the Iranian capital, plumes of smoke blanketed the city’s sky, where millions of people live. Scientists consulted by the international media have pointed out that the mix of pollutants released in these fires — carbon monoxide, nitrogen oxides, sulphur dioxide and volatile organic compounds — is typical of extreme industrial accidents, but is rarely observed on such a scale in such a densely populated urban environment. Researcher Akshay Deoras, from the University of Reading, stated that the scale of the pollutants released could be “unprecedented”, whilst Professor Eloise Marais, from University College London, warned that the episode is equivalent, in chemical terms, to the simultaneous explosion of several industrial facilities.
One of the most disturbing phenomena reported by residents of the Iranian capital has been the so-called “black rain”. This term describes precipitation laden with soot and chemical residues that darken the water as it falls. The process occurs when airborne particles—resulting from oil fires or explosions—are captured by raindrops and carried to the ground. Although rain can partially cleanse the atmosphere, it also deposits pollutants on streets, homes, crops and water systems, facilitating their infiltration into aquifers and their entry into the food chain.
Air pollution is just one aspect of this crisis. The war has also released toxic waste from munitions, explosives and industrial materials. When buildings, storage facilities and factories are destroyed, the rubble disperses hazardous substances such as lead, mercury, asbestos or complex hydrocarbons that can remain in the environment for decades. These pollutants become fixed in the soil, degrading its fertility and affecting its capacity for regeneration, compromising agriculture and food security across vast regions.
The impact on human health is both immediate and long-term. The Director-General of the World Health Organisation, Tedros Adhanom Ghebreyesus, has warned that the destruction of energy infrastructure “risks contaminating food, water and air”, with serious consequences for the most vulnerable populations. Exposure to fine particles and toxic compounds not only causes acute respiratory conditions but also increases the risk of chronic diseases and cancer in the long term.
Impact on Iran and the Gulf
But the scale of the environmental disaster is not limited to Iran. The conflict has also spilled over into the sea, particularly the Persian Gulf and the Strait of Hormuz, one of the world’s most important energy corridors. Attacks on oil tankers and military vessels have caused oil spills that form surface films on the water, reducing oxygenation and affecting fish, seabirds and coral reefs. These ecosystems, already weakened by global warming, could suffer irreversible damage if the spills continue.
Added to this is the risk to critical infrastructure such as desalination plants, which are essential in a region where access to fresh water depends on the sea. Seawater contamination can render these systems inoperable or reduce their capacity, triggering a water crisis in the midst of war.
Ground intervention scenario
In this already critical context, the eventual opening of a ground front by the United States on Iranian territory would represent a qualitative leap in environmental degradation. Unlike air and naval warfare, ground operations involve a prolonged occupation of the territory, the massive deployment of armoured vehicles, heavy artillery and troops, as well as the systematic destruction of infrastructure across vast areas. This type of warfare intensifies soil contamination through the direct dispersal of heavy metals, fuels, lubricants and explosive residues.
Historical experience shows that ground conflicts leave behind persistent ‘weapons contamination’, characterised by the presence of mines, unexploded ordnance and chemical residues that can remain active for decades, affecting ecosystems and civilian populations. These elements not only pose a physical danger, but also release toxic substances that contaminate water and soil, damaging biodiversity and hindering environmental recovery.
Furthermore, ground operations often lead to the direct destruction of natural habitats, deforestation and the fragmentation of ecosystems. The passage of heavy vehicles compacts the soil, alters its structure and reduces its water absorption capacity, promoting erosion and desertification. In arid regions such as much of Iran, these effects can be particularly severe and long-lasting.
Another critical factor is the collapse of environmental management systems during protracted wars. The monitoring of discharges, the protection of water resources and the management of hazardous waste cease to function, accelerating ecological degradation. The United Nations has warned that armed conflicts cause ‘accelerated environmental degradation’ precisely because of the breakdown of these control mechanisms.
In a scenario of ground occupation, large-scale consumption of fossil fuels would also increase, due to the intensive use of military vehicles, logistics and heavy machinery, which would boost global greenhouse gas emissions. This phenomenon, combined with the destruction of energy infrastructure, would exacerbate the climate impact of the conflict.
Furthermore, the consequences would not be limited to Iranian territory. Pollutant particles generated by explosions and earthworks can be carried by atmospheric currents for thousands of kilometres, whilst the contamination of rivers and aquifers can spread to neighbouring regions. In this sense, ground warfare would amplify the global dimension of the environmental crisis already underway.
Nuclear impact
Added to this picture is the risk associated with damaged nuclear and chemical facilities. Although no significant radioactive leaks have been confirmed so far, the deterioration of sensitive infrastructure in the context of ground combat would increase the likelihood of incidents with potentially catastrophic consequences.
The difficulty in assessing the actual impact of the conflict further complicates the assessment. Independent organisations have identified hundreds of incidents with environmental consequences, though they warn that the actual figure could be much higher due to lack of access and information restrictions.
The consequences of this pollution may extend far beyond the Middle East. Particles released by oil fires and explosions can travel thousands of kilometres and affect even remote regions, altering glaciers, soils and ecosystems. In this sense, the war becomes a global environmental phenomenon.
Meanwhile, on the ground, the most visible effects remain the unbreathable air and the devastated landscape. But experts agree that the true extent of the disaster will be measured in the years and decades to come, when persistent pollutants continue to affect health, agriculture and ecosystems.
The conflict in the Persian Gulf is demonstrating that the environment is not collateral damage, but one of the main victims of war. And if the conflict were to escalate into a ground invasion, that invisible victim could turn into an ecological catastrophe of historic proportions.
