Modern armed conflicts and military activities bring horrors, especially in the form of human casualties and destroyed cities. But the silent and long-term sacrifice that we all share – our planet and its climate – is often forgotten. From the daily operation of military bases After active combat operations, military activities are some of the most carbon-intensive activities on Earth. These activities not only directly devastate local ecosystems, but also contribute massively to global warming, creating a vicious cycle in which climate change acts as a multiplier for other security threats.

Military Carbon Footprint: The World's Fourth Largest Polluter

Scientific estimates show that routine military operations around the world are responsible for about 5.5 trillion tons of global greenhouse gas emissions. If the world’s militaries were a single country, they would rank as the fourth-largest carbon footprint in the world, surpassing countries like Russia. The United States military alone is the world’s largest institutional consumer of hydrocarbons. Its annual emissions are equivalent to those of entire countries like Serbia. Since the start of the War on Terror in 2001, the US military has released an alarming 1.2 billion tons of greenhouse gases into the atmosphere.

The extreme carbon intensity is largely due to the poor fuel efficiency of most military equipment. As experts note, military vehicles, ships and aircraft are measured in „gallons per mile“ rather than „miles per gallon.“ The true extent of the problem is likely to be even greater, however, given the lack of accurate data. Loopholes in the 1997 Kyoto Protocol and subsequent agreements have allowed militaries to avoid strict reporting of their emissions. The largest military players, such as the US, China and Russia, either do not report their military emissions at all or provide incomplete and inaccurate data to the United Nations Framework Convention on Climate Change (UNFCCC).

Direct destruction of nature and toxic pollution during wars

While peaceful military operations produce massive amounts of CO2, active warfare brings about immediate and often irreversible ecological disaster. The explosion of each munition releases toxic particles of heavy metals such as lead, mercury, zinc and depleted uranium into the environment. These substances penetrate the soil and groundwater, from where they enter the bodies of animals and humans through the food chain. Compounds from explosives such as TNT and RDX cause cancer, organ failure and mutagenic changes. Depending on conditions, it can take 100 to 300 years for munitions residues in the soil to completely decompose.

Fighting in heavily industrialized areas is particularly devastating. Targeted and accidental attacks on chemical plants, oil refineries, and coal mines lead to large-scale releases of hazardous substances. During the war in Ukraine, we witnessed attacks on facilities such as Sumychimprom, which caused an ammonia leak, or the destruction of nitric acid tanks in Severodonetsk, which forced the population to take shelter from toxic clouds. Fertile soil also suffers physical destruction. Heavy military equipment such as tanks compacts the soil, destroys microbial communities, and leaves the earth's surface contaminated with petroleum substances.

Water resources and biodiversity as victims of conflicts

Wars also have a profound impact on water resources and biodiversity. The destruction of strategic water infrastructure has catastrophic consequences. The destruction of the Kakheti Dam in June 2023 caused the flooding of vast areas, the washing away of toxic sediments accumulated from decades of industrial activity, and the local extinction of rare fish species, including the protected sturgeon. Attacks on water treatment plants and sewage systems, such as on the Severny Donets River, led to the release of untreated sewage and heavy metals, leaving millions of people without access to drinking water.

Flora and fauna themselves are also suffering. Areas that are home to rare and endangered species are turning into battlefields. In Ukraine alone, more than a third of the protected areas belonging to the pan-European network have been affected by war. Explosions, fires and military sonar have caused enormous losses in animal life; for example, thousands of dolphins have died in the Black Sea, succumbing to acoustic trauma, disorientation and toxic pollution. National parks such as Dzharylhach have been virtually destroyed as a result of fighting and massive mining.

The climate cost of conflict and the long road to recovery

The conduct of war itself is a huge generator of emissions. It is estimated that the first two years of the war in Ukraine alone produced up to 175 million tons of CO2 equivalent. Other studies put the figure at up to 230 million tons, a carbon footprint comparable to the annual emissions of a developed country like Spain. These emissions include not only the burning of fossil fuels by military equipment, but also large-scale forest and infrastructure fires. In addition, the indirect consequences of conflict, such as disruption of energy supplies, often force countries to return to coal, further undermining global efforts to implement the Paris Agreement.

However, the climate burden does not end with the end of the fighting. The post-war reconstruction of the destroyed infrastructure will require an enormous amount of construction materials, especially concrete and steel, the production of which is one of the largest sources of CO2. According to estimates by the World Bank and related studies, the planned reconstruction of Ukraine will generate a carbon footprint of 781 million tons of CO2. This figure represents more than 4.3 times the annual emissions of the whole of Ukraine before the war. For this reason, experts are calling for a green reconstruction – maximum use of recycled materials from rubble and modernization of the construction sector, otherwise the reconstruction will have a devastating impact on the climate.

We can no longer afford to ignore the environmental and climate impacts of military activities. It is worrying that global military spending is rising at a time of deepening climate crisis. Transparent reporting of military emissions, including those directly generated in combat (so-called Scope 3 Plus), and the integration of militaries into international decarbonization goals must be a priority. Sustainable peace is not only about the absence of weapons, but also about protecting the climate and nature, without which long-term human security is impossible. JRi&CO2AI