Europe's Military Expansion and the Looming Threat of Climate Collapse

Last week, all 27 EU heads of state met in Brussels to oversee the continent’s largest military expansion in decades—a response to Cold War-level tensions. Yet, as Europe re-arms, a bigger threat looms: climate collapse, which no arsenal can deter.

With unchecked climate change poised to halve global GDP in decades, security now hinges on rethinking energy itself—starting with the military.

Insurance experts warn that unchecked climate change could slash global GDP by 50% in the coming decades, destabilizing economies and societies alike. Security isn’t just about defense budgets and troop deployments; it’s about maintaining the economic foundations that nations rely on.

As Europe re-arms, the critical question is this: Will it invest in a military that locks itself into fossil fuel dependence—or will it seize the opportunity to lead in green defense innovation, securing both its national security and economic future?

"We cannot choose between either green or strong armed forces; we need strong and green at the same time."

Modern Warfare and Fossil Fuels: A Problematic Relationship

Modern warfare is fueled by oil, and that’s a problem.

• Global militaries account for up to 5.5% of total CO₂ emissions, surpassing the emissions of entire nations like Japan or Russia.
• The U.S. Department of Defense alone emits more than Sweden or Portugal, making it the world’s largest institutional consumer of petroleum .
• Fuel transport missions in Iraq and Afghanistan exposed the high cost and vulnerability of oil-dependent supply chains. In 2007 alone, an estimated 170 servicemembers were killed or wounded safeguarding fuel convoys—casualties that starkly illustrate how these missions, relentlessly targeted by insurgents, became a lethal liability for American troops.

“If the military are the only ones using fossil fuels, then we will need to do our own exploration, our own refineries, our own logistics of the whole fuel chain, and that cannot be reality.”

“We thought we had a deal with Gazprom, but we actually had a deal with Mr. Putin.”

A fossil-free military would significantly reduce these vulnerabilities, decreasing dependence on adversary-controlled energy sources and unstable fuel supply chains. While jet fuel and diesel remain essential due to their unmatched energy density, a clear, phased transition toward biofuels, hydrogen, and electrification—starting with logistics and base operations—could meaningfully lower risks from geopolitical threats, volatile energy markets, and rising operational costs.

Critics argue that fossil fuels’ energy density remains unmatched for combat, but phased transitions—starting with bases and logistics—prove the shift is feasible without sacrificing readiness.

Yet military emissions are only part of the challenge. The deeper issue is energy dependency itself—one that exposes supply chains to geopolitical shocks and battlefield vulnerabilities.

For decades, military power has relied on oil-fueled logistics chains, diesel-powered armored vehicles, and jet fuel-reliant air forces. But as climate change accelerates, this dependence has become a direct national security risk.

That risk isn’t just tactical—it’s economic. As mentioned before, insurance experts warn that unchecked climate change could slash global GDP by 50% in the coming decades—driven by crop failures, mass migration, and resource wars—triggering economic and social destabilization on a scale never seen before.

Geopolitical energy shocks also remain a significant threat. Russia’s invasion of Ukraine exposed Europe’s dangerous reliance on Russian fossil fuels, a vulnerability that directly extends to military energy supply chains.

Meanwhile, China is rapidly positioning itself as a global leader in military clean energy innovation. From hydrogen-powered drones and AI-driven autonomous combat vehicles to nuclear-powered warships, China is integrating next-generation technology into its defense strategy. Perhaps most ambitiously, it is exploring space-based solar power—aiming to beam limitless, renewable energy from orbit to sustain military operations without reliance on fossil fuels. If Europe delays its transition, it risks not only an economic setback but also a strategic disadvantage in the energy-driven warfare of the future.

"A significant improvement in energy ratios can also be achieved for military operations. Optimizing energy efficiency during deployed operations places special demands on technology. We look forward to using our skills and experience to support our customers' sustainability goals."

Military Innovation and Cleantech Leadership

Military R&D has transformed global industries before, and it can do so again:

• The Internet & GPS- Originally developed for military use, now essential for global commerce.
• Nuclear Power- First used in military submarines before becoming a global fossil-free energy source.

A European commitment to green military technology would ensure both strategic dominance and cleantech leadership.

A whole array of recent examples prove that clean defense tech is not a pipe dream. Sweden’s JAS 39 Gripen fighter has successfully flown on 100% biofuel, demonstrating that high-performance military aircraft can transition to renewable energy. In France, the military has implemented “Eco Camp 2025,” deploying solar-powered field bases to reduce reliance on fuel convoys. Meanwhile, the British Army has developed hybrid-electric armored vehicles that lower fuel consumption and improve stealth, with future models potentially incorporating hydrogen propulsion to further reduce emissions.

The war in Ukraine is demonstrating the strategic advantage of low-emissions weaponry. Ukrainian forces have successfully integrated low-cost, commercially available drones into frontline operations, reducing reliance on fuel-intensive military vehicles and aircraft. These drones offer enhanced battlefield agility, cost-effectiveness, and tactical flexibility—delivering precision strikes and reconnaissance at a fraction of the cost and carbon footprint of traditional weapons systems. This shift not only improves operational efficiency but also underscores the future of warfare: adaptable, decentralized, and less dependent on fossil fuels.

The race for clean military technology is already underway. China has rapidly positioned itself as a leader in green defense innovation, integrating next-generation energy solutions into its military strategy. If Europe delays, it risks not only an economic setback but also missing a crucial opportunity to lead the future of defense.

In 2024, China’s investment in clean energy reached nearly the scale of global fossil fuel investments, totaling approximately $940 billion. More than half of this investment went into its electric vehicle, battery, and solar industries, significantly outpacing other global markets. Importantly, Beijing controls critical minerals like lithium, copper, and rare earth metals, securing a key advantage in the next generation of military and civilian energy

If Europe fails to transition to a fossil-free military, it risks not only being outmaneuvered in conflict but also becoming strategically dependent on foreign energy technologies.

The Path Forward: Energy Independence and Strategic Dominance

The fundamental role of military power is not to wage war, but to prevent it. A well-equipped, energy-independent military serves as a deterrent, reducing the likelihood of conflict. But while a strong military can deter adversaries, it cannot deter climate collapse.

If Europe integrates clean energy innovation into its military modernization, it will secure long-term energy independence, freeing itself from volatile oil markets and ensuring operational resilience. By leading the world in military cleantech, Europe has the opportunity to gain both strategic and economic dominance, setting the global standard for sustainable defense. At the same time, investing in fossil-free military technology will reduce global security risks, addressing climate-driven instability before it escalates into full-scale conflict.

However, if Europe remains locked into another century of fossil fuel dependence, it risks being outpaced by China, which is rapidly advancing in military clean energy innovation. Operational costs will rise as fossil fuel prices fluctuate and supply chains become more fragile, making European forces increasingly vulnerable to energy shocks. Even its own deterrence capabilities could weaken, as outdated energy infrastructures fail to keep pace with the evolving demands of modern warfare.

The choice is clear: Europe can lead the future of defense by embracing a fossil-free military—or risk falling behind in the new era of security and power.

Europe is at a crossroads: it can embrace military clean tech—or double down on outdated systems. Unfortunately, recent defense procurements suggest that some nations are still stuck in the past.

Despite the clear strategic and economic benefits of a fossil-free military, many defense procurements continue to lock in outdated technology. A striking example is Sweden’s recent €1.4 billion procurement of 775 military trucks. Instead of investing in modern, lower-emission alternatives, all vehicles were ordered with diesel engines based on the Euro III emissions standard—a regulation that is 25 years old and has been replaced multiple times. These trucks will remain in service for decades, further entrenching fossil fuel dependency in Sweden’s military infrastructure. The reasoning? A perceived need for ‘maintenance simplicity’ and avoiding reliance on modern emissions-control technologies like AdBlue. Yet while Sweden locks itself into fossil fuel dependence, other militaries are proving that hybrid and electric alternatives are already combat-ready and operationally effective.

This failure to modernize is not just an environmental issue—it’s a missed opportunity for strategic leadership. While China and other global powers invest heavily in green military technology, Europe risks falling behind by making procurement decisions based on outdated assumptions rather than future security needs.

With €800 billion in military investments planned, the EU faces a decisive moment: lock in fossil fuel dependence or shape the next generation of global security.

To prioritize security, Europe must mandate green procurement in its defense budget, accelerate military-to-civilian tech transfers, and foster public-private cleantech partnerships—steps that overcome oil industry resistance to ensure energy independence and leadership. No military can defend against climate collapse, but innovation and investment can. The window is narrowing—Europe’s future depends on acting now.