How increasing global military expenditure threatens SDG 13 on Climate action

This paper was prepared in response to a call from the UN Office for Disarmament Affairs on the impact of the global increase in military expenditure on the achievement of the sustainable development goals:

In the Pact for the Future, adopted by the General Assembly in September 2024, Member States voiced their concern about the potential impact that the global increase in military expenditures could have on investments in sustainable development and sustaining peace. To that end, the General Assembly requested the Secretary-General to “provide analysis on the impact of the global increase in military expenditure on the achievement of the Sustainable Development Goals by the end of the seventy-ninth session”.

Summary

This paper outlines the impact of rising military expenditure on the achievement of Sustainable Development Goal 13: take urgent action to combat climate change and its impacts, looking specifically at the following targets:

• Strengthen resilience and adaptive capacity to climate-related hazards and natural disasters in all countries;
• Integrate climate change measures into national policies, strategies and planning;
• Implement the commitment undertaken by developed-country parties to the United Nations Framework Convention on Climate Change to a goal of mobilizing jointly $100 billion annually;
• Promote mechanisms for raising capacity for effective climate change-related planning and management in least developed countries and small island developing States, including focusing on women, youth and local and marginalized communities.

Through reviewing a range of research and presenting this alongside the historical and present context of military expenditure, this analysis finds that the global increase in military expenditure poses a substantial risk to the achievement of SDG 13.

Contents

Introduction

SDG13: Climate action

Target 13.1: Strengthen resilience and adaptive capacity to climate-related hazards and natural disasters in all countries

Target 13.2: Integrate climate change measures into national policies, strategies and planning

Target 13.3: Mobilize climate finance commitments undertaken by developed-country parties to the United Nations Framework Convention on Climate Change

Target 13.4.b: Promote mechanisms for raising capacity for effective climate change-related planning and management in least developed countries and small island developing States, including focusing on women, youth and local and marginalised communities

Conclusion

Recommendations

Introduction

The global increase in military expenditure has far reaching consequences, negatively impacting multiple of the Sustainable Development Goals (SDGs). This submission will focus solely on the implications for SDG 13: Climate action, as this is the expertise of the authors, but we wish to stress that this is simply one of many SDGs that are at risk due to rising military expenditure.¹

The world has now marked a decade of rising military spending, with the global total now standing at a record breaking $2.7 trillion annually. Russia’s invasion of Ukraine prompted a dramatic increase in European Union (EU) military spending, and between 2021 and 2024, EU member states’ total military expenditure rose by more than 30%. In 2024, it reached an estimated €326 billion – about 1.9% of EU GDP,² almost reaching the NATO target of 2% which is set to rise.³

Whilst this submission will focus on the current ‘rearmament’ efforts being led by EU and NATO states, it is important to place this in the context of military spending over time. Some of the world’s largest militaries have been dedicating these levels of spending, and more, for decades. Since records began in 1948, the United States has never spent less than 3% of its GDP on its military; in 2023, the annual total stood at $916 billion. Similarly, Russia has only dropped below 3% once since the fall of the Soviet Union (earlier data is not available), reaching an estimated $145.9 billion in 2024.⁴ Chinese military expenditure has been rapidly increasing for the last 20 years and while it may appear that China spends less than 2% of GDP on its military, it is suggested that this is an incomplete picture and the true share is likely higher.⁵ Global superpowers have been normalising spending a higher share of GDP on military budgets for far longer than this current period of ‘rearmament’.

Militaries are huge energy users whose greenhouse gas emissions (GHG) make a significant contribution to the climate crisis. However, countries do not systematically record and report their military emissions so the real share of this source of emissions remains unclear. The Conflict and Environment Observatory (CEOBS) and Scientists for Global Responsibility estimate that everyday military activity could be responsible for around 5.5% of global emissions, meaning that if the world’s militaries were a country, they would be the fourth largest emitter in the world.⁶ Furthermore, as military spending increases and the rest of society decarbonises, that proportion is set to rise.

Fundamentally, increasing military spending will increase military emissions. Ramping up military production to increase stockpiles is energy-intensive and, while technological advances in lower carbon military technologies remain limited, the current procurement push together with the reliance on older and allegedly more known and thus trusted technologies means that militaries will be locked into fossil-fuel intensive equipment to be used for decades to come. A recent report from the European Defence Agency noted the lack of standardised ‘green’ procurement across EU militaries, with less than 40% of respondents reporting a ‘green’ procurement policy in place;⁷ noting that ‘green’ does not necessarily equate to low-carbon in this context. However, it has been found that military expenditure contributes to a rise in emissions even when technological progress with the military sector is taken into account,⁸ contributing to the so-called treadmill of destruction effect where the general dynamics of militarisation can harm the environment outside of direct impacts.⁹

The current military spending increases are happening at a particularly damaging time for the climate. According to the latest data, global GHG emissions are on course to exceed the budget for a 67% chance of staying below the 1.5C temperature change by 2027.¹⁰ In short, this target – specified in the Paris Agreement – is about to be breached, even without the current rearmament programmes. Climate scientists have pointed out that above this level, the damage from climate change accelerates, and the chances of exceeding ‘tipping points’ for irreversible climate change – such as ice-sheet melting, ocean circulation changes, or major ecosystem collapses – increases markedly.¹¹ Continuing current mitigation policies is only estimated to limit warming to 3.1C by 2100,¹² and these policies do not take into account the climate impacts of rapidly rising military budgets.

As military spending increases, accurate data will be essential to understand the implications for global emissions. However, states are currently not obliged to transparently report on the full scope of their emissions from their militaries in their national reporting to the UN Framework Convention on Climate Change (UNFCCC). While some may choose to publish their military emissions independently, this is often far from the full picture. This means that we don’t have a fully accurate understanding of the impact that militaries are having on global emissions, which limits our ability to assess progress towards Goal 13: Take urgent action to combat climate change and its impacts.

This submission will largely focus on the climate impacts of military emissions, which we define as the emissions from everyday military activity. This includes a range of sources across scopes 1, 2 and 3 as detailed in A Framework for Military GHG Emissions Reporting,¹³ such as equipment use, building and construction, and waste management. Notably, this submission will not draw from the increasing amount of literature covering the climate impacts of armed conflicts, although these impacts are substantial. The Initiative on the GHG Accounting of War calculates that the emissions from three years of Russia’s invasion of Ukraine has resulted in 230 MtCO₂e, the equivalent of the annual emissions of Austria, Hungary, Czech Republic and Slovakia combined.¹⁴ The emissions from the first 120 days of the Israel-Gaza conflict have also been estimated to have exceeded the annual emissions of 26 individual countries.¹⁵ It is noteworthy that since there is no agreed framework for measuring or reporting the emissions from conflicts, this contributes to the broader gap in international emissions reporting and a limit to our ability to assess progress on Goal 13 overall.

Currently, there is an active debate within the academic community on how military spending affects the likelihood of armed conflict. Military and political actors often argue that military spending increases can be necessary to maintain credible deterrents and prevent or limit armed conflict. However, historical analysis by academics has shown that such spending rises often lead to arms races which actually increase the risk of war.¹⁶ Moreover, in recent decades, the situation has been complicated by the introduction of new weapons technologies, which make judgements on the effectiveness of deterrents more difficult. Meanwhile, a range of factors other than increasing military spending levels have been shown to reduce the likelihood of armed conflict.¹⁷

This submission will focus on one aspect where there is clear evidence: that rising military expenditure is for the most part negatively impacting our ability to achieve SDG 13 on climate action.

SDG 13: Climate Action

Target 13.1: Strengthen resilience and adaptive capacity to climate-related hazards and natural disasters in all countries

There are broad concerns that increased military spending may divert resources away from efforts to strengthen resilience and adaptive capacity in all countries. For example, researchers have highlighted the opportunity costs associated with military expenditure, emphasizing how it diverts resources away from policies aimed at mitigating climate change.¹⁸ This situation seems to be playing out in Europe currently, with the UK, Belgium, France and the Netherlands all slashing aid budgets while increasing military spending (although only the UK has explicitly connected the two).¹⁹ Whilst it is too soon to see the explicit impacts of aid cuts or analyse what programmes will be hit the hardest, there is a clear risk that developing countries that benefit from overseas aid to strengthen their capacity to respond to climate-related hazards and natural disasters will be impacted.

Despite these concerns, militaries are often uniquely positioned to provide rapid and effective responses to climate-related disasters due to their logistical capabilities, trained personnel, and equipment,²⁰ as well as societal trust. For instance, in June 2024, southern Germany experienced catastrophic flooding that caused widespread devastation. The Bundeswehr, Germany’s armed forces, played a crucial role in providing timely support to relief efforts.²¹ They delivered essential supplies, distributed blankets and camp beds, and assisted in stabilising affected communities. Likewise, NATO’s Euro-Atlantic Disaster Response Coordination Centre “has helped fight everything from forest fires in Latvia and Israel to earthquakes, snowfalls, and floods in Albania and Montenegro, […] relief to the United States in the aftermath of Hurricanes Katrina and Harvey,”²² thus highlighting the humanitarian side of the alliance. This short-term gain can complement long-term resilience-building efforts.

While the short-term benefits of military humanitarian response are evident, it is crucial to ensure that any increased military spending does not come at the expense of investment into civilian climate adaptation and disaster preparedness, to ensure that states are able to strengthen resilience and adaptive capacity to climate-related hazards and natural disasters. One option to mitigate this risk is to strategically integrate military assets into climate adaptation frameworks, so that governments can harness their potential while ensuring that long-term resilience-building efforts remain a priority.

To support disaster response capacity building, governments could identify which disaster response activities may be more appropriately carried out by civilian agencies, especially if they were provided with the funding and equipment to do so. Since military equipment is designed specifically for combat, it may be either more expensive or less-adapted to disaster relief and humanitarian responses than dedicated civilian equipment. Increased international sharing of civilian equipment may support this effort and help reduce duplication of effort and reduce costs, as has been done with aircrafts for wildfire control in Europe.

Target 13.2: Integrate climate change measures into national policies, strategies and planning

Rising military expenditure poses a risk to integrating climate change measures into national policies, strategies and planning, in particular to governments’ net zero policies. In this section, we will break this down to examine the impacts of military spending on both military emissions and national emissions, as well as explore recommendations of strategies to reduce this impact.

The context of increased military spending among European/ NATO member states in particular is concerning as research has suggested that the military expenditure of developed nations result in disproportionate GHG emissions due to their technologically advanced and capital intensive military forces.²³ Furthermore, these impacts can be seen to extend beyond carbon emissions directly attributable to the military; maintaining large and technologically advanced military establishments transforms and exacerbates carbon pollution across the larger economy and society.²⁴

The impacts of increases in military spending on military GHG emissions

Increases in military expenditure threaten national mitigation targets in both direct and indirect ways. Because militaries and their supply chains are major fossil fuel users, rising military spending leads to direct increases in military GHG emissions through three main pathways:

• increases in military activity, through increased fossil fuel use in: training and exercises; routine patrols; and (at times of war) armed conflict;
• increases in the numbers of military personnel, through increased fossil energy use at military bases, or through increased construction of bases; and
• increases in military procurement, through fossil energy and other resource use in the manufacture of current equipment, or research and development for future equipment.

These factors have been identified in several studies over the past five years at national, regional, and global scales.²⁵

The exact relationship between military spending and GHG emissions is, however, complex and difficult to define, especially due to the deficiencies in emissions data. Nevertheless, researchers have identified certain relationships. For example, a 2023 study on NATO emissions derived the following equation:²⁶

Carbon footprint of the military, including the associated military technology industry =
(military expenditure) x (proportion spent on equipment) x (spend–emission conversion factor) + (number of military personnel) x (average stationary emission per military head)

Military expenditure is also an indirect factor in the equation for calculating military GHG emissions derived in a 2022 study on global emissions.²⁷

Despite the difficulties in defining the exact relationships between military spending and military GHG emissions, the evidence from these studies points to increases of tens to hundreds of millions of tonnes of carbon dioxide equivalent (tCO₂e) per year resulting from current spending increases.

The impacts of increases in military spending on national GHG emissions

Increases in military expenditure can also lead to increases in GHG emissions in the wider civilian economy in several ways:

• diverting funding and other resources away from programmes to reduce GHG emissions to general military programmes;
• diverting funding and other resources away from civilian programmes to reduce GHG emissions to military programmes to reduce GHG emissions, the latter generally being less effective per unit cost due to the ‘hard to abate’ nature of military programmes (see below);
• continued ‘lock-in’ of national economic dependence on fossil fuels – especially oil – due to their value in military platforms, and consequent conservatism in initiatives to diversify to low carbon sources;
• fuel-switching to higher carbon fuels – e.g. LNG via ships replacing fossil gas via pipelines during the Ukraine war – to deal with conflict-related disruption to global energy supplies.

To show how increased military expenditure directly impacts overall emissions at the national and international levels, we have developed a case study using NATO member states excluding the USA. We have chosen to exclude the USA as levels of US military spending have remained high for some time, as referenced in the introduction. Within the current context of European rearmament, the European Commission has presented the ReArm Europe Plan/Readiness 2030 proposal which calls for an €800 billion boost to Europe’s military budget.²⁸ Assuming that this is spent within four years, this boost will increase military spending by one percentage point of GDP. Exceptions to deficit rules are to be made, which will allow an overall 1.5% GDP increase in military spending by member states. Since military spending already increased from 1.5% GDP in 2019 to 2.0% GDP in 2024,²⁹ the ReArm Europe Plan could lead to a further increase of up to 3.5%, which is a military expenditure shock of 2% compared to 2019. We have assumed that a similar expenditure shock will happen at non-EU NATO members, i.e. the United Kingdom, Norway, Canada and Türkiye.

A recent paper argues that an increase in military spending of one percentage point of GDP increases overall national emissions by between 0.9% and 2.0%.³⁰ With the total annual emissions of these 31 countries being 4,861 million tCO₂e (2023),³¹ the increase of annual emissions would amount to between 87 and 194 million tCO₂e. As it will take time for the equipment to be produced and enter into operation, and in turn start consuming fossil fuels, this increase may take a period of a few years to become visible. As military platforms have a lifespan of several decades, each new military purchase will lock-in emissions for decades to come.

The impact of these increased emissions will exacerbate the climate crisis and will cause additional damage to the economy and society at large. This damage can be expressed by the Social Cost of Carbon (SCC) which is a monetary indicator of the damage for each additional tonne of CO₂ emitted in the atmosphere. The most recent study estimates the SCC to be 1,347 USD/tCO₂.³²

As a result, we calculate that the collateral climate damage caused by NATO’s increased military spending amounts to $119 – 264 billion per year.

This example of 31 countries represents only 9% of total world emissions. Should more countries follow the trend of increasing military spending, as is likely in Asia, the contribution to global emissions may mean that even meeting the overarching goal of the Paris Agreement to limit the increase in global average temperature to well below 2°C becomes unattainable.

Strategies to reduce military GHG emissions

Some militaries have begun to publish military strategies for mitigating their GHG emissions to pursue ‘green military’ programmes, however these face numerous obstacles. Firstly, a military will in general not contemplate reducing its emissions if it also reduces its ‘firepower’, which risks limiting the extent to which progress can be made. Secondly, the military sector is one of the hardest to decarbonise through technological change. The World Economic Forum has identified eight ‘hard-to-abate’ sectors,³³ and armed forces are part of three of these – aviation; shipping; and trucking – while their supplies are heavily dependent on at least three of the others – oil and gas; steel; and aluminium. In addition to this, militaries are expected to operate under the extreme conditions of warfare, which significantly adds to the innovation obstacles already encountered by their civilian counterparts. Thirdly, many military platforms are designed and built to last for decades, and as a result, the introduction of new technologies can be very slow unless there is a combat-related imperative.

Preliminary analysis of the small amount of historical data on military GHG emissions reinforces these concerns.³⁴ This has found that large falls in emissions tend to happen when:

1. military spending decreases;
2. military activity decreases, e.g. following the end of a war or armed confrontation;
3. the number of active military personnel decreases;
4. the numbers of large fossil fuel-dependent vehicles are reduced;
5. fuel-switching takes place for energy supplied to military bases, most commonly decarbonisation of national electricity grids; and/or
6. fuel-switching takes place within military bases, most commonly from coal to fossil gas or renewables for heating.

For the most part, options 1-4 are not likely to happen and there is considerable resistance to them. Options 5 and 6 are underway in some nations, where 5 is being carried out by civilian organisations, however there remain considerable obstacles to other technological options for the reasons outlined above. This means that a large fall in military emissions is currently unlikely through these avenues, which has an inevitable impact on efforts to reduce national emissions in countries with large militaries.

However, there are other options available to governments within their policymaking that can limit the impact of militaries on the national GHG mitigation efforts, such as:

• shifting to ‘non-offensive’ defence strategies –³⁵ where long-range, fossil fuel-intensive military platforms are minimised, and the military focus is on territorial defence;
• promoting ‘common security’ approaches to dealing with conflict, which emphasise diplomacy and peace-building strategies;
• refocusing international security strategies to emphasise ‘human security’ rather than military force,³⁶ so that tackling problems such as poverty, inequality, and environmental degradation is given much higher priority. Increased investment in achieving the SDGs would be an example of this approach.

Target 13.a: Implement the commitment undertaken by developed-country parties to the United Nations Framework Convention on Climate Change to a goal of mobilizing jointly $100 billion annually by 2020 from all sources to address the needs of developing countries in the context of meaningful mitigation actions and transparency on implementation and fully operationalize the Green Climate Fund through its capitalization as soon as possible.

As well as limiting the availability of funding for the climate action as noted above, increasing military expenditure is also negatively impacting developed countries’ ability to meet climate finance commitments. At COP29, parties to the UNFCCC were tasked with agreeing on a new climate finance commitment to replace the existing goal of $100 billion annually by 2020. At the World Leaders Climate Action Summit which opened COP29, multiple states confronted the disparities between developed countries’ increasing military budgets and limited climate finance commitments, for example:

• Nepal: “The vast resources spent on arms should be redirected to mitigation efforts.”
• Cuba: “Alternative [financial] resources need to be found […] At the same time, what is happening is that defense expenditure worldwide in 2023 rose 9% to 2.3 trillion dollars, and the US is at the forefront of this expenditure. We cannot remain passive while death is given priority over life.”
• Panama: “Global military spending stands at about $2.5 trillion yearly. $2.5 trillion to kill each other is not too much, but 1 trillion to save lives is unreasonable.”

Ultimately, COP29 failed to secure the level of commitment from developed countries that developing countries were calling for;³⁷ the Least Developed Countries Group said that they were “outraged and deeply hurt by the outcome of COP29… We leave Baku without an ambitious climate finance goal”.³⁸ COP29 was a clear sign that the prioritisation of military spending over climate action has not gone unnoticed by developing countries, which risks straining multilateral processes.

More directly, developed country governments have specifically slashed aid and development budgets to fuel a rise in military spending. For example, the UK government recently announced that it would reduce aid spending by 0.2% GDP to fund higher military expenditure,³⁹ a move that has been called “a reckless decision that will have devastating consequences for millions of marginalised people worldwide” by the CEO of Bond, the UK network for organisations working in international development and humanitarian assistance. Under the previous government, £1 billion in military aid for Ukraine was partly funded by “surrendering climate finance and foreign aid underspends”, taking funds from the UK’s International Climate Finance programme and Official Development Assistance (ODA) budget to fund military aid.⁴⁰ Whilst other governments may not have drawn the same direct connections as the UK government, this sits within a wider trend across developed countries of increasing military spending while slashing aid budgets. This will inevitably impact countries’ ability to deliver on their climate finance commitments as aid budgets become increasingly stretched.

The redirection of resources from climate finance to military spending has significant broader implications for achieving Target 13.a. Firstly, it undermines trust between developed and developing countries, as the $100 billion climate finance goal is seen as a critical commitment from wealthier nations, who have historically contributed the most to global GHG emissions. Failure to meet this goal risks eroding trust and weakening international cooperation on climate action. Secondly, it delays the full operationalisation of the Green Climate Fund, which relies on consistent and adequate funding from developed countries to support large-scale climate projects, such as renewable energy infrastructure and disaster resilience programs in developing nations. Lastly, reduced climate finance exacerbates the vulnerability of developing countries, which are often the most affected by climate change but lack the resources to address its impacts. This makes it harder for them to implement meaningful mitigation actions and build resilience to climate-related hazards, as outlined in Target 13.1, further hindering global progress toward sustainable development.

Target 13.b: Promote mechanisms for raising capacity for effective climate change-related planning and management in least developed countries and small island developing States, including focusing on women, youth and local and marginalised communities.

The communities of least developed countries and small island developing states have been facing the impacts of militarism and climate change simultaneously, including women, youth and marginalised groups.

For example, in Palau, the local children have brought a case against the US military to the UN Special Rapporteur on Indigenous Peoples and the UN Special Rapporteur on the human right to a clean, healthy, and sustainable environment. The youth argued that the US Army is destroying ecosystems, disturbing sacred sites, threatening endangered species, and breaking environmental laws,⁴¹ and the residents of these territories have feared that their lands might be a war target. This is in direct opposition to the empowerment of local communities and limits the local capacity for climate change-related planning and management since the environmental mismanagement is caused by an external actor, the US military. In particular, the contested military activities include deforestation, which directly contradicts local climate change adaptation and mitigation needs and hinders long-term climate change-related planning and management.

This is just one example of how the climate resilience of communities is impacted by the presence of a foreign military base, yet military bases are found across the globe and frequently in least developed countries and small island developing states. For example, for countries like Djibouti whose locations are strategically useful, communities can find themselves alongside military bases belonging to Germany, Spain, Italy, France, the United States, the United Kingdom, China, and Saudi Arabia.⁴²

Whilst it is not clear whether the current increase in military expenditure will drive an expansion of foreign military bases, on the contrary France is planning their withdrawal from many African bases,⁴³ existing militarism is having a direct effect on local communities’ ability to effectively plan for and manage climate change.

Conclusion

As this paper highlights, the global increase in military expenditure has clear negative implications for achieving the targets of SDG 13: climate action. Furthermore, this current drive for rearmament only builds on the existing impact that militarism has had on global emissions for decades. It is clear that UN Member States were fair to voice their concern about the potential impact that the global increase in military expenditures could have on investments in sustainable development and sustaining peace.

This paper draws on the increasing body of research focused on the military’s contribution to the climate crisis and wider environmental damage. However, it is important to note that progress in this area of research is hindered by a lack of transparency and a consequent gap in data on military emissions. The availability of more data would open up the possibility for researchers to have a greater understanding of the impact that militaries are having on climate change, which in turn would support bodies like the IPCC to provide the most accurate and up-to-date science for climate policymaking. Moving forward, this is crucial.

This is a critical moment that calls for action from the UN and Member States; 2024 was the warmest year on record at about 1.55°C above pre-industrial levels, suggesting that the Paris Agreement target to limit warming to 1.5°C is severely at risk. In fact, the past ten years since 2015 have been the ten warmest years on record.⁴⁴ If we are to keep within the overarching goal of the Paris Agreement to limit warming to well below 2°C, we need urgent action and the current rate of military expenditure is incompatible with this goal. Ambitious GHG emission reductions are essential in the next 5-10 years and if governments are not willing to reduce emissions from their militaries, society must be prepared to make compensatory plans for greater reductions in other sectors.

We can no longer bury our heads in the sand and ignore the climate impact of dramatically rising military expenditure. The authors’ recommendations present some tangible next steps that would support the international community to measure and mitigate the impacts of rising military expenditures on climate action, and we remain available to support this process.

Recommendations

In addition to the recommendations made throughout this paper based on the evidence gathered, the authors suggest the following overarching recommendations:

• Governments should commit to military GHG emissions reporting that is robust, comparable and transparent, and which covers the full scope of military activity including stationary emissions, mobile emissions, and supply-chain emissions, as well as emissions from warfighting where relevant.
• The Intergovernmental Panel on Climate Change (IPCC) should update its Guidelines for National Greenhouse Gas Inventories to facilitate comprehensive reporting of military GHG emissions to the UN Framework Convention on Climate Change (UNFCCC).
• Governments should commit to ambitious and comprehensive plans for the reduction of military GHG emissions, which cover the full scope of military activity including stationary emissions, mobile emissions, and supply-chain emissions, as well as emissions from warfighting where relevant.
• Governments should be transparent and clearly communicate to the public how increased military expenditure decisions impact their contribution to the SDGs, and in particular the overarching goal of the Paris Agreement to limit the increase in global average temperature to well below 2°C.

Ellie Kinney, CEOBS, UK; Dr Stuart Parkinson, Scientists for Global Responsibility, UK; Lennard de Klerk, Initiative on the GHG Accounting of War, Netherlands; Prof Gregory Hooks, McMaster University, Canada; Dr Erwei Xiang, Newcastle University, UK; Madara Melnika, European University Institute, Italy. With thanks to Doug Weir (CEOBS) and Jan Selby (University of Leeds) for their feedback.