War’s Carbon Shadow: The Hidden Climate Cost of Militaries and Conflict

Apr 22
5 min read

Article by Kumud

Introduction

Few realise that militaries can be among the world's largest institutional polluters, operating outside the frameworks designed to hold nations accountable for their emissions. Today, the defence of a nation is handled by its military and brings a sense of security to its people. But this security has its tradeoffs. The environmental impacts of a physical war begin long before it starts and persist for decades afterwards, as efforts to recover continue. While discussions around the humanitarian losses and struggles are most important, the environment has always been the silent casualty of armed conflicts. This essay thus argues that understanding and reporting the environmental footprint of militaries and armed conflicts is essential for credible global climate action.

Understanding the Environment and Climate Footprint

Emissions from Military

The military is one of the most energy-intensive sectors globally. It is more carbon-intensive than the individual civilian sectors like aviation or shipping, primarily due to its heavy dependence on fossil fuels¹^,³. Military emissions reporting is voluntary under the UNFCCC and is often excluded due to lobbying by certain countries over the potential leakage of sensitive military data. The countries that do report military emissions are usually incomplete or are not segregated under the IPCC categories.¹²

Thus, current estimates, such as “Militaries are responsible for an estimated 5.5% of global emissions,” are often based on tracking fuel use or military spending. To put the number into perspective, the military would be the fourth-largest national greenhouse gas emitter globally.⁵

The military's emissions can be categorised into four main groups.³ The first is due to the supply chains for manufacturing and procurement of military equipment. The second is fuel use, both stationary (for the operation of military bases, etc.) and mobile (for the transportation of naval and aviation fleets). The third is land use for training and defence buildings. Lastly, there is waste management and disposal of weapons.

A study that analysed the correlation between global military expenditure as a percentage of GDP (also known as the MILEX ratio) and CO2 emission intensity from 1995 to 2023 revealed a significant positive correlation with a Pearson correlation coefficient of 0.83, exceeding the 95% confidence interval². This is explained by the fact that a higher MILEX ratio corresponds to the expansion of military activities, which is amplified on a global scale through supply chains and trade.

Emissions from War

However, military emission estimates during peacetime only tell us half the story. The other half lies in the destruction and damage from wars and their aftermath. Emissions during a war can be understood as direct and indirect.⁴

Direct emissions encompass the use of weapons and fossil fuels. Warfare explosives cause severe air, water, and soil pollution, as well as fires, releasing hazardous substances into the environment. For example, the effects of nuclear weapons continue to sicken and kill people long after the fighting ends.

Furthermore, deforestation driven by conflicts permanently reduces the capacity of vital carbon sinks, compromising their ability to mitigate climate change. During the war in Ukraine, the Deputy Minister of Environmental Protection and Natural Resources in Ukraine stated that military operations were conducted in over a third of Ukraine’s protected natural areas⁸. Wetlands of international importance, known as Ramsar sites, have been directly suffering from military activities in Ukraine, according to the “Assessment Report of environmental damage on Wetlands of International Importance in Ukraine stemming from the Russian Federation’s aggression”⁷.

In many conflicts, biodiversity loss and land-use change occur not only as unintended outcomes but as deliberate targets. Another example is during the Vietnam War (from 1965 to 1973), when the US military deliberately eradicated the forests in Vietnam using herbicides. The most prominent being Agent Orange, the effects of which persisted after the war and subsequently led to a 50% decline in mangrove forest cover⁹.

Indirect sources of emissions are more evident during prolonged conflicts. Underdevelopment, a lack of investment, and disengagement from international agreements and projects all lead to a country being stuck in old, polluting technologies, such as increased dependence on wood or coal for fuel and heating, the dumping and burning of waste, and untreated wastewater. This not only increases emissions but also negatively impacts the quality of life for its people.

Recovery from wars also leads to emissions from waste and debris management and from the construction of new infrastructure. One of the most recent examples is the toll of war in Gaza. With an estimated 75,000 tonnes of explosives dropped and 42 tonnes of debris that are potentially hazardous, it could take over 40 years to rebuild Gaza, provided there is no further blockage.¹⁴ The environmental costs of such a rebuilding project are immense, including energy use, production and procurement of cement and other construction materials, and the transportation of goods.

Importance of Tracking Emissions

Given the aftermath, the ideal scenario is for no wars ever to happen, as the writer H.G. Wells once said: “If we don’t end war, war will end us.” However, security will be a non-negotiable requirement for nations, and under that notion, the military must fulfil its duties.

However, there is still merit in quantifying the environmental impacts of global tensions. Such transparency and scrutiny will help reduce the accountability gap and, hopefully, emissions, paving the way for better policy responses to tackle climate change and geopolitical challenges.

There is also a growing understanding of the impacts of climate change and environmental degradation, which are driving greater displacement, social unrest, instability, and even conflict. The phenomenon is known as the climate-security nexus. It is a cycle of issues in which conflict causes environmental damage, and these increased ecological impacts and climate disasters may further lead to conflict over food, clean water, and air.

Progress?

It may be ironic to discuss green military; however, a few large military technology companies, such as Lockheed Martin and Thales, produce CSR and ESG reports and set net-zero targets, suggesting that there is pressure on companies to appear green and take climate action.⁵

Switzerland has committed to making its army carbon neutral by 2050, aiming to achieve this goal by transitioning to renewable energy sources, reducing fuel consumption, and planting trees to offset the remaining emissions.¹¹ Despite the army being relatively small in its missions and capacities compared to other nations, it is a start.

Understanding the reasons for increased emissions during and post-conflict can also put into perspective the potential to create more opportunities to build back cleaner, greener, and more sustainable urban development by bringing to the forefront rapidly developing sustainable technologies.

Conclusion

Thus, there is an urgent need to discuss and develop concrete reporting standards for military technologies and activities, and to make them compulsory within the UNFCCC. Such a commitment will enable accelerated progress of the military sector alongside the rest of the global sectors on the path to achieving the targets of the Paris Agreement. The military was built to protect borders, citizens, and sovereignty — but in the age of climate change, the most existential threat wears no uniform. If militaries are truly in the business of protecting humanity, then the environment can no longer remain their silent casualty.

War’s Carbon Shadow: The Hidden Climate Cost of Militaries and Conflict

Introduction

Understanding the Environment and Climate Footprint

Emissions from Military

Emissions from War

Importance of Tracking Emissions

Progress?

Conclusion

References:

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