Journal article published by the Royal United Services Institute, March 2025.
The article argues that climate change must be integrated into defence planning as both a physical and ethical challenge. Using the UK Ministry of Defence (MoD) as a case study, the article introduces the concept of the “climate flank”—a vulnerability in defence capability arising from failure to adapt to and mitigate the impacts of climate change. The central concern is whether militaries can retain their “licence to operate” amidst changing public expectations, legal standards, and climatic conditions.
The Climate Flank: Defining the Threat
The “climate flank” refers to three interlinked threats:
- Losing moral legitimacy due to unchecked emissions.
- Facing operational disruptions in hostile climatic environments.
- Ceding advantage to more agile or ethically unconstrained adversaries.
These risks, if not addressed, could lead to diminished freedom of movement, reduced public support, and strategic disadvantage. The author draws parallels to accepted flanks like air and cyber, suggesting climate should be treated with equal doctrinal seriousness.
Doctrinal and Operational Readiness
Military doctrine, known for its planning rigor, can serve as a model for climate adaptation. Climate change’s primary (e.g., weather extremes), secondary (e.g., migration), and tertiary (e.g., legal norms) effects can disrupt all levels of warfare. The MoD’s Climate Change and Sustainability Strategic Approach outlines ambitions for adaptation, sustainability, and global leadership, highlighting the urgency of integrating climate concerns into strategic planning.
Fighting Power and Environmental Responsibility
The article incorporates NATO’s three components of fighting power—conceptual, physical, and moral—to climate preparedness. The moral component, deemed pre-eminent in UK doctrine, now includes environmental responsibility. Reducing emissions, especially from non-operational sources, and enhancing transparency can safeguard the moral licence to operate. While militaries inevitably generate emissions, deterrence and rapid response may prevent conflicts that would be even more carbon-intensive.
Mitigation and Adaptation Strategies
The article outlines a comprehensive 12-point mitigation strategy. Key recommendations include:
- Transparent emissions accounting.
- Prioritising emission reductions in home-base infrastructure and logistics.
- Leveraging renewable energy and hybrid technologies.
- Redesigning forces for self-sustainment and reduced logistical dependence.
- Aligning environmental compliance with host nation values to maintain access and legitimacy.
Adaptation, meanwhile, requires climate-proofing equipment, doctrine, and training. The MoD must revise Defence Standards and consider extreme climatic conditions in future acquisitions. Technological innovation, such as automation and directed energy weapons, can reduce environmental and operational risks.
The article concludes with a warning that without immediate and sincere integration of climate considerations, militaries risk operational failure, loss of public support, and violation of moral war principles. A holistic approach grounded in doctrine and strategic planning is essential for safeguarding freedom of manoeuvre, securing access, and maintaining battlefield advantage in a climate-changed world.
This text is based on extracts from a journal article written by Matt Stott, March 2025. The complete article can be found here.
See below for our coverage on similar topics:
- Climate Change and the Military: Discourses and Practices
- Irish Defence Forces Review 2024: Climate Change, Security and Defence
- Imbuing Climate Security with Positive Peace