Climate Security and the Strategic Defence Review 2025

As this paper reminds, Hannibal’s legendary Alps crossing turned environmental adversity into strategic opportunity. Today, the UK must adopt a similarly bold mindset to confront the security implications of climate change. The 2025 Strategic Defence Review (SDR) acknowledges climate change as a “persistent transnational challenge” that reshapes operating environments, drives instability, and demands military adaptation. Yet, while the SDR identifies climate risks – from High North geopolitics to humanitarian crises – they remain secondary to traditional threats like state aggression and cyber warfare.

This paper critiques that imbalance, arguing for climate change to be recognised not just as a background hazard but as a front-line strategic threat. Climate change is already acting as a threat multiplier, intensifying food insecurity, mass displacement, and infrastructure stress – vulnerabilities adversaries can exploit. The SDR gestures toward military adaptation (e.g. Arctic readiness, disaster relief) and energy resilience (market-led renewables on bases), but lacks the urgency, funding and institutional structures to match the scale of the challenge.

The UK risks lagging behind allies. NATO and EU states are advancing dedicated climate-security plans, scenario-based war-gaming, and emissions reductions across defence estates. This paper calls for the UK to do the same: including establishing a Climate Security Intelligence Centre, integrating climate scenarios into all defence planning, and linking net-zero ambitions with sovereign defence-industrial resilience.

Crucially, climate security must become a whole-of-government effort – spanning FCDO diplomacy, MOD capabilities, and civil contingency planning. Without this integration, climate-driven shocks will strain unprepared forces and systems.

The SDR rightly seeks to make Britain safer. To do so in a climate-volatile world, defence strategy must treat climate change not just as context, but as a core insecurity driver. As Hannibal turned terrain into tactical advantage, so must the UK master the climate threat – with foresight, resilience, and adaptation at the heart of national security. See full article here.