The global stage witnesses a perplexing paradox: while national defense budgets surge, climate adaptation within the military remains significantly behind. This creates a dual challenge for militaries worldwide – maintaining core security missions while urgently adapting to the accelerating climate crisis. The situation is further complicated by the sector’s immense contribution to greenhouse gas emissions, a “war on greenhouse gas emissions,” as Doug Weir, director of the Conflict and Environment Observatory (CEOBS), aptly describes it.
The urgency of this issue was brought to the forefront in 2007 during the UN Security Council’s first debate on climate change and security. Since then, interest in the impact of climate change on military operations has grown, as noted by Sofia Kabbej, a researcher at the French Institute for International and Strategic Affairs (IRIS). However, according to CEOBS, scrutiny of the defense sector’s environmental impact remains remarkably low. The organization estimates the sector contributes a staggering 5.5 percent of global annual emissions.
The impetus for change is growing. Militaries are now actively reviewing their practices not only to meet climate goals but also to maintain strategic advantage in a rapidly shifting geopolitical landscape. The core military function – the ability to operate anytime, anywhere – remains paramount. However, there’s a growing recognition that environmental responsibility doesn’t compromise readiness, quite the contrary.
Past military operations and training exercises have caused considerable environmental damage. Chemical warfare agents and heavy metal pollution (like lead) pose severe risks to both military personnel and civilian populations. The path forward involves employing techniques to minimize hazardous waste and adopting less polluting materials. Streamlining sustainable practices across all military activities can also create more eco-friendly humanitarian support operations, where soldiers often assist communities or act as first responders in crises like earthquakes or natural disasters.
The military’s energy consumption and pollution are substantial. Simon Baumann, an officer in NATO’s Multinational Capability Cooperation Unit, points out that, on average, 6 percent of national military budgets are allocated to logistics and fuel supply. Reducing fuel dependency offers significant emission reductions and delivers strategic and financial benefits. “There’s a huge economy of scale for us to drive down costs,” Baumann emphasizes.
Nations like the UK are already adopting hybrid-electric drive systems for military trucks and armored vehicles. Many armies are exploring on-site renewable energy production (solar and wind power) and hydrogen fuel cells in military bases. Even in air defense, where alternative energy sources are less readily available, emissions-cutting measures are underway. The Royal Air Force’s Director of Support and Chief Engineer, Shaun Harris, highlights the shift towards simulated training environments to reduce costs and emissions. Norway’s Chief of Defence, Erik Kristoffersen, emphasizes the use of advanced flight simulators for their F-35s, resulting in increased training efficiency, reduced wear and tear on the fleet, and less maintenance.
Rising global temperatures pose a direct threat to military readiness. By 2050, regions such as the Middle East could experience prolonged periods of extreme heat—daytime highs of 50°C and nighttime lows of 30°C. The increasing frequency of droughts and wildfires necessitates equipment and strategy adaptation for effective operation in unpredictable environments. Armies are developing strategies to protect personnel and maintain operational capabilities under these extreme conditions. These include heat-reflective and cooling-system uniforms, along with smart energy systems for climate-resistant infrastructure. These innovations enhance soldier safety and improve the efficiency of humanitarian operations in increasingly heat-stressed regions.
Despite the challenges, defense emerged as a clear winner in this year’s national budgets. NATO countries are striving to reach the alliance’s 2 percent GDP target for defense spending amid escalating geopolitical tensions. In 2021, NATO launched a Climate Action Plan aiming for net-zero emissions by 2050. Kabbej considers this a recognition of climate change as a security issue requiring decisive action. Countries also see a clear advantage in accelerating green technology investments for operational gains. Hybrid-electric technologies, for example, offer significant stealth benefits due to near-silent operation. Hydrogen fuel cells minimize thermal signatures, enhancing invisibility to thermal detection systems.
Constantinos Hadjisavvas, project manager at the European Defence Agency (EDA), stresses the urgency of immediate action: “Military systems often have lifespans of 20 to 30 years, meaning that achieving net zero by 2050 requires immediate action to avoid locking in carbon-intensive technologies.” Weir advocates for improved transparency in military emissions reporting, emphasizing the need to understand the sector’s contribution and its impact on resource allocation.
Despite NATO’s climate action plan and various national initiatives, sustainability remains a secondary concern for many defense sectors. France’s Climate Advisor to the Armed Forces, Alex Bastienne, stated that their primary climate focus is on energy efficiency, not comprehensive sustainability reforms. Kabbej warns that given the delays in civilian climate action and the geopolitical context, climate adaptation may not be prioritized despite the growing vulnerability of even the world’s most powerful militaries. Furthermore, Weir argues that increased defense spending directly translates into higher military emissions, fueling the very climate crisis cited as a threat to national security, creating a dangerous feedback loop.
