Europe’s security is no longer confined to conventional threats like tanks, missiles or cyberattacks. This summer’s record-breaking heatwaves have exposed a new reality: climate is a threat that can be weaponised.
Wildfires don’t just burn forest; they can paralyse societies, overwhelm hospitals and force military deployments.
As the threats are equally real whether triggered by global warming or saboteurs, the line between environmental crisis and national security is blurring — and Europe is ill-prepared.
Wildfire risks extend beyond the environment
Europe has always been susceptible to wildfires, but the increasing volatility of its climate – as demonstrated by long-term drought, extreme heat and strong winds — has amplified both their frequency and potential to wreak havoc.
In Spain, wildfires in 2025 have burned over a record 400,000 hectares of land, with temperatures consistently above 40°C. In Cyprus, 13,150 hectares have burned — equivalent to 2.3% of the island’s territory. But the impacts of extreme heat and wildfires extend far beyond environmental damage.
Healthcare systems are overwhelmed with an immense cost to human life. Between 16 May and 13 July 2025, Spain recorded 1,180 heat-related deaths, compared with just 114 in the same period in 2024. An estimated 2,300 people died across 12 European cities during a single ten-day heatwave in July, with around 65% of fatalities attributable directly to climate change.
Wildfires and extreme heat depress economic growth and productivity. Estimates project that heatwaves could reduce European GDP growth by 0.5% this year, with losses ranging from 0.1% in Germany to 1.4% in Spain. One day of extreme heat above 32°C is equivalent to half a day of strike action.
Critical infrastructure is also under strain. The heatwave of late June saw power demand in Spain increase by 14%, as air conditioning use increased. Heatwaves drive electricity demand to record levels, produce supply bottlenecks, force price spikes and stress on grids, and expose vulnerabilities in underprepared transport networks.
These are not just environmental problems — they are strategic liabilities in a tense geopolitical environment.
Wildfires as a warfare tactic
In times of war, the impacts of wildfires could be catastrophic, and potentially fatal. It is not hard to see why countries may begin to view wildfires as effective and efficient tools of war, much like cyber warfare. The US Department of Defence already warned of the risk in 2019.
National security strategies should therefore be prepared to respond. They must integrate climate-driven threats — heatwaves, water shortages, wildfire risk — as existential hazards. Infrastructure resilience should be a priority, from energy storage and demand-flexible grids to microgrids, cooling shelters and water capture systems.
The green transition should be recognised as a core element of security policy and governments must not be afraid to address these issues through defence spending. Renewables and decentralised generation reduce emissions and enhance energy independence. Strategic autonomy, long a defence goal, is directly supported by investment in clean-energy systems.
Defence planning must also include protection of vulnerable populations. Early warning systems, cooling centres and resilient shelters are as vital to national security as tanks and missiles.
Borderless threats require a borderless response
Heatwaves and wildfires do not respect national borders. EU-wide mechanisms such as the Civil Protection Mechanism, its programme to strengthen civil protection cooperation between the EU countries and participating states, will need reinforcement, with stronger shared assets and faster coordinated deployment.
The military, already called upon in climate-related emergencies, will increasingly serve as first responders. They must be adequately trained, equipped and integrated into national and EU-level climate security planning, not called as a last resort.
From the scorched fields of Galicia to the evacuated villages of central Portugal, the heat and flames of 2025 have shown that climate resilience must be written into Europe’s defence architecture.
If Europe fails to treat climate resilience as a pillar of defence, it risks leaving its people, infrastructure and sovereignty exposed to a weapon that knows no borders.
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