I had the honor of joining the opening panel, the State of Climate Security, at the Montreal Climate Security Conference hosted by the NATO Climate and Security Center of Excellence and the Conference of Defense Associations on 7 October, 2025. This essay is based on my remarks.
When it comes to climate security, the world is in a dangerous moment. Instead of closing the gap between the climate security threat and the military and security community’s responses, that gap is widening.
For years, the dominant framework for understanding climate change in the security field has been the “threat multiplier” model—asking how climate affects existing priorities such as countering Russia, competing with China, and curbing terrorism. This framing is accurate and useful: climate change does worsen many existing security challenges. It is also politically convenient. By using this model, we can assure defense communities that we’re not asking them to take on new missions or care about new issues—we’re simply helping them do their jobs better.
One example that exemplifies the threat multiplier model is a US State Department International Security Advisory Board report that included a case study of how climate impacts could shape a conflict over Taiwan. The report modeled how a typhoon or other extreme storm might knock out key infrastructure, disrupt supply chains, block reinforcements, and heighten the risk of miscalculation. It’s an excellent piece of analysis—and we need more like it.
But it’s not enough.
Climate change does not just multiply existing threats; it creates entirely new ones. Too few militaries and security institutions grasp this. As I argue in Climate Change on the Battlefield, “even militaries that take climate change seriously tend to see it as something that merely alters or adds to their existing missions instead of considering the potential for climate change to fundamentally reshape or reorient their core duties.”
This moment demands that we step back and remind ourselves of the purpose of militaries and alliances. NATO, for example, defines its essential and enduring purpose as “safeguarding the freedom and security of its members.” Yet one of the most profound threats to that security now comes from the destabilizing effects of climate change. Measured in the most precious metric, human lives, climate impacts already far outstrip many traditional security threats. In 2022, one of the hottest years on record, Europe saw 15,000 heat-related deaths and the UK another 4,500—compared with just over 6,700 deaths globally from terrorist attacks. Add to that the economic toll, damage to critical infrastructure, and the potential to reshape national interests, and it becomes clear that climate change is not peripheral—it is central to national and collective security.
So perhaps we need to flip the usual question. Instead of asking only how climate affects our current missions, we should ask how our current missions affect our ability to confront the new security threats climate change is generating.
Those threats are accelerating. We are entering a climate-changed world with no historical analogue. As Josh Busby describes, this is the “end of stationarity”—a world where past patterns no longer predict future risks. John Vaillant captures this psychological challenge in his book, Fire Weather: humans tend to think the worst thing they’ve ever experienced is the worst thing they will ever experience. Climate change doesn’t just mean more frequent disasters—it means greater uncertainty and the potential for discontinuities and shocks: a collapse of the Atlantic Meridional Overturning Circulation, the melting of the Greenland ice sheet, or simultaneous failures of multiple global breadbaskets. Disruption, not continuity, will define the coming decades.
And yet, as the climate threat becomes clearer, our security institutions seem less willing or able to meet the moment. The phrase “climate change” wasn’t uttered once at the last NATO Summit. A senior EU official reportedly laughed when asked whether investments in climate adaptation and disaster response could be considered defense spending. Militaries from Canada to the United States to Australia continue to treat disaster response as a distraction from their “core” duties, remaining reactive rather than proactive, even as climate hazards increasingly drive operational demand.
This inward turn, amid rising nationalism and faltering trust, risks creating dangerous blind spots. Many governments are refocusing their militaries on state-centric threats, dismissing climate as a “soft” issue. In doing so, they not only expose themselves to risk but also miss major opportunities for strategic advantage. Climate resilience offers “no regrets” investments—buy one, get five or ten free—in stability, capability, and deterrence.
Consider the issue of hybrid threats. At the NATO Summit in June, defense ministers warned of gray-zone attacks on infrastructure, food systems, and information networks. In the months that followed, climate-driven hazards exposed exactly those vulnerabilities. Europe faced a record wildfire season, with over one million hectares burned and hundreds of troops deployed. Heatwaves strained electricity systems, doubling energy prices. Food systems wobbled. Public frustration grew as citizens blamed governments for poor early warning and inadequate preparation, even calling for resignations. Each of these events revealed a ripe hybrid-attack surface for adversaries to exploit. Investments in climate resilience directly reduce that exposure.
In this more fragmented and competitive world, militaries that invest fully in preparing to absorb and manage the shocks of climate change will be the ones with the advantage. Resilience is the name of the game. Managing climate risks is not a distraction from defense: it is defense. Such investments are not just threat reducers; they are stability multipliers that will yield resilience dividends for decades to come.