The security threat of climate change has never been more stark, as highlighted by Hurricanes Helene and Milton devastating communities, killing hundreds, drawing vast civilian and military relief, triggering foreign and domestic disinformation, and disrupting military readiness and diplomatic coordination on Ukraine. This underscores the urgency of concrete action on efforts like September’s White House’s Framework for Climate Resilience and Security and the call by the new U.K. Foreign Secretary to put climate change at the center of its foreign policy. But taking real action on climate change requires moving beyond double standards about uncertainty and treating it in the same way as other security risks.
A Common Red Herring
Rather than outright denial, climate skeptics often dispute the certainty of climate forecasts or the risks they entail. At a Senate hearing earlier this year, the Trump administration’s acting administrator of the National Oceanic and Atmospheric Administration (NOAA) acknowledged climate change’s reality but downplayed its importance to national security, arguing “climate models are rife with uncertainty.” Elsewhere, national security analysts search desperately for the perfect model or tool to predict the exact time, location, and nature of climate-driven crises. This is, in part, a reflection of wider political rhetoric that has long invoked alleged uncertainty to downplay climate change. In an August 2024 interview with Elon Musk, former President Donald Trump updated his argument that climate change is a “hoax” to say, “we have perhaps hundreds of years left. Nobody really knows.” Musk agreed, recognizing climate change but alleging “the risk is not as high” as feared, until we reach carbon dioxide (CO2) concentrations of 1000 parts per million, causing headaches.
From a national security perspective, such thinking is off-base for a few reasons.
Uncertain Compared to What?
First, compared to most security issues, we have a luxurious amount of certainty about climate risks. While some technical questions require more precision to answer, we know the big picture: even if we cut emissions rapidly, climate change will inevitably worsen for decades. The only question is: how much?
If we had such long-term confidence about an India-Pakistan war,, cyber threats, or North Korean instability, we would act. Few would advocate waiting for perfect certainty. At least six key climate “tipping points,” which could have catastrophic impacts on stability, are at risk on our existing trajectory. And the level of CO2 Musk considers the threshold for alarm would equate to about 5 degrees Celsius of warming. At this (thankfully unlikely) level of warming, headaches would be less of a concern than the chaos from worldwide crop shortages, mass casualty heatwaves, economic devastation, and flooding of coastal cities.
Moreover, the entire business of national security and foreign policy is navigating uncertainty. To be sure, there is some uncertainty in projections of climate change and the complex implications for security and foreign policy. But cyber and terrorist threats, wars, diplomatic negotiations, and humanitarian emergencies are all “rife with uncertainty,” because of things like the secret intentions of world leaders, the volatile causes of political instability, and luck. That is why intelligence analysts, diplomats, military planners, and aid workers get paid. As the late General Gordon Sullivan once said of climate science, “As a soldier, we never have 100 percent certainty. If you wait until you have 100 percent certainty, something bad is going to happen on the battlefield.”
The Stakes Are High, So Act Accordingly
To be fair, even with an enlightened outlook some uncertainty about climate security risks is unavoidable. That warrants a conversation about managing risk, defined as a threat’s likelihood and its potential consequence. When the consequences are high, we need airtight certainty a threat is averted before feeling reassured. Everyone understands this intuitively–it’s the difference between a 30% chance of heartburn and a 30% chance of a heart attack. Intelligence analysts often caveat that despite lacking evidence, “we cannot rule out” things like terrorist plotting in the US or a secret Iranian nuclear breakout. This is because potential invasions, nuclear weapons, and terrorist attacks are treated more like heart attacks than heartburn. Climate change demands the same level of care. This is especially true because climate change could be less disruptive than anticipated, or it could be more so, as recent science suggests.
But in fact, climate change’s politicization and unfamiliarity can incentivize security experts to pull their punches or over fixate on getting more precise projections, to avoid accusations of bias or alarmism. Indeed, even impressive assessments like the Department of Defense’s Climate Risk Assessment, and the National Intelligence Estimate on climate change spend relatively little time on the plausible worst-case climate scenarios, mirroring a broader gap in research. And the US Defense Science Board’s study on climate change and global security emphasizes that “models do not address the necessary DoD-relevant operational spatial and timescales.” This is arguably true, but a standard for foresight not applied to other future challenges the DOD routinely plans around, whether the pace of Chinese military modernization, the trajectory of terrorist threats, or prospects for Iran’s nuclear ambitions.
Aim for the Best, Prepare for the Worst
A better approach would be to not be cowed by potential accusations of alarmism, and spend more time examining plausible extreme outcomes.
Just like we plan for unlikely outbreaks of nuclear conflict, what would the implications for global security and stability be of the collapse of the Greenland and West Antarctic ice sheets, die-off of low-latitude coral reefs, abrupt permafrost thaw or some combination thereof? These are all possibilities on the existing temperature trajectory, and not alarmist fantasies or even “low-probability, high-impact” events, to invoke an intelligence analysis term. Just as we consider the implications of simultaneous wars, what if catastrophic climate disasters coincided with a crisis in Taiwan or elsewhere? Or, similar to how we evaluate foreign soft power and ideological trends, we can consider how climate change might contribute to new authoritarian or extremist movements. Or just as military fortunes can reverse, we might ask how reversible is our progress in the fight against climate change? What if geopolitics, energy needs, or climate disruptions themselves prompt backsliding on emissions targets, a reversion to fossil fuel-intensive coping strategies, or a crackup of the Paris Agreement coalition? This is not to say any or all these things are certain or even likely, but they are certainly plausible and consequential enough to consider.
Climate scientists are experts on the Earth, but national security practitioners are experts in risk, uncertainty, and conflict. They are trained in high stakes decision-making despite uncertainty. Given the stakes and complexities of climate change, we shouldn’t waste their comparative advantage. Here, non-academic methods like intelligence analysis, wargaming, scenario planning, and crisis simulation are valuable tools and should be extended outside their traditional defense and intelligence communities. In some cases, provocative questions might best be approached in a “what if?” framing. The specifics of the COVID-19 pandemic could not have been predicted decades in advance, but we certainly would have benefited from building greater resilience and contingency plans before February 2020. The same applies to climate disruptions.
Finally, where clarity on high-stakes questions remains elusive, that uncertainty should be an argument for more prudent action, not less. In many cases, erring on the side of caution is a “no regrets” investment. If it turns out we were slightly too cautious, we will not have wasted our effort investing in more resilient systems of food, water, energy, health, diplomacy, economics, and defense.
Climate has not been prominent in the 2024 US presidential campaign, but as we move into the second half of the 2020s severe climate impacts will be front and center regardless of political leanings. Like any important global issue, we lack perfect certainty on climate change. But, we have more than enough certainty to warrant greater action, especially on sorely lacking resilience and adaptation investments at home and abroad. National security and foreign policy analysts should treat climate risks with the gravity they would other threats, and not shy away from uncertainty or plausible worst-case scenarios, which are arguably where they are needed most. Meanwhile, analysis is meaningless without policy action, and here policymakers will need to grow more comfortable taking prudent action to prevent or adapt to climate security disruptions, even in the absence of certainty. With climate change intensifying all around us, our collective security depends on it.