Brussels – Increasing global military spending risks seriously undermining the achievement of the UN Sustainable Development Goal number 13 dedicated to action against climate change. This is the warning issued by a new study published by the Conflict and Environment Observatory (CEOBS), which points out that the growth in defence investment is translating into an increase in greenhouse gas emissions, a diversion of public resources from environmental policies, and an obstacle to international cooperation on climate change.
In 2023, global military spending reached $2.4 trillion, the highest level ever recorded. Europe, in particular, has experienced an acceleration in defence spending in response to a geopolitical context characterised by instability and armed conflict. According to the report, this global trend is creating an environment in which military priorities tend to take precedence over climate ones, with knock-on effects on government budgets, decision-making processes and long-term strategic directions.
The expansion of military budgets has a direct impact on the climate through increased emissions, as the activities of the armed forces, ranging from air transport to land vehicles and infrastructure management, are heavily dependent on fossil fuels. However, the detection of these emissions still remains partial, often excluded from the environmental monitoring systems required by international climate agreements. The report highlights that this lack of transparency is a structural issue that hinders the full integration of the defence sector into decarbonisation efforts.
In addition to the direct impact, increased military spending also produces indirect consequences. Increased defence funding reduces the fiscal space available to finance climate mitigation and adaptation policies. At a time when scientists are calling for massive and immediate investment in the energy transition, this competition between priorities risks slowing down or undermining goals already set at the national and international levels. The CEOBS paper points out that even where states declare ambitious climate goals, increasing militarisation ends up diverting the attention and resources needed to achieve them. Achieving Goal 13 requires not only effective climate policies but also an international environment conducive to cooperation. The report notes how the growing logic of armed confrontation, fuelled by increased military spending, tends to undermine the mutual trust that underpins multilateral climate agreements. In this sense, militarisation is not only an emissions problem, but also represents a diplomatic and political obstacle that renders the entire global climate governance process more fragile.
Europe is in a particularly delicate position. On the one hand, it is the protagonist of a new phase of strengthening its defence capability, also within NATO. On the other hand, it has taken a leadership role in the fight against climate change, committing to achieving climate neutrality by 2050. The report points out that the risk is that the balance between these two priorities will be tipped. According to the International Institute for Economics and Peace, between 2021 and 2024, EU member states’ arms expenditures increased by more than 30 per cent. The RearmEu programme, announced in March 2025, envisages an additional allocation of €800 billion. In this scenario, the competition between security and sustainability is likely to become structural: the resources allocated to environmental protection could shrink further, while emissions related to military activities would likely increase.
A rapid rearmament untethered to the goals of the ecological transition could therefore cost Europe much more than damage to its image: in the absence of a turn in this direction, experts warn, the risk is that global efforts to contain global warming below 1.5 °C will become unfeasible.
English version by the Translation Service of Withub
