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Heat is a National Security Threat. Why Isn’t It Treated as One?

By the time we come to a shared conclusion, it may be too late.

Words: Connor Sutherland
Pictures: Michael Held

The National Weather Service issued its first ever Excessive Heat Warning in Maine in June, as a heat dome punished its inland counties with 105-degree weather — a record in a state known for its temperate climate. Elsewhere, heat waves continue to broil countries like India, Pakistan, and Saudi Arabia, where this spring cities like New Delhi, Jacobabad, and Mecca have regularly experienced temperatures in the mid-to-high 120s, setting records while exposing millions of poor and working people to heat that has so far killed thousands and sent hundreds more to hospitals. In regions both accustomed and ignorant to such unforgiving heat, people — especially the most vulnerable — are grappling with its devastating effects more than ever. 

Indeed, barely into the summer season, 2024 is proving to be the hottest year on record — this after last year also carried that same distinction. While historically it has been difficult to understand exactly how (or even if) human-caused climate change influenced the frequency and severity of specific weather events like heat waves, advances in attribution science has allowed experts to clarify the relationship: Burning fossil fuels and emitting greenhouse gases makes heat waves like the ones detailed above more likely, more intense, and longer. 

Climate change and its various symptoms are unlike traditional threats from which, as Winston Churchill succinctly put it in 1938, the United States is “happily protected by the Atlantic and Pacific Oceans.” First and foremost, heat and the carbon emissions that exacerbate it are borderless: Emissions from industrialized nations like the United States, China, and Russia have inflicted trillions in damages on developing nations, particularly in the Global South. Second and unlike fundamentalist terrorists, Russian revanchism, and China’s regional aggression — the risks that the United States has spent untold amounts of political capital, money, and lives trying to combat in recent years — climate change is an existential national security threat. 

Not only are record-setting temperatures themselves a threat, they also serve to worsen other existing hazards, risking both US interests at home and abroad as well as global stability writ large. And instead of a comprehensive plan to mitigate the root causes of climate change and cope with its repercussions, American climate security strategy has, at best, been limited to superficial assessments of its impact on force readiness — hardly a sufficient response.

Cooking at Home

In late June, a record-breaking heatwave bore down on more than 100 million people across the United States, straining public response systems in rural communities and dense urban centers alike, endangering vulnerable populations and crippling critical infrastructure. And despite containment efforts, wildfires blazed in California and New Mexico, killing at least two people and hastening evacuation efforts around across the West. 

Similar reports made headlines last summer, when temperatures above 110 degrees were measured every day for a record 31 days in Arizona and were 100 or above in Texas for 44 days. Researchers found that such conditions were responsible for the deaths of more than 11,000 people in the United States — nearly five times the official number, which itself is hundreds more than the deaths certified heat-related in 2022. And as 2024 continues to break records, this year could be a tragic continuation of this deadly trend. 

Indeed, a recent study predicts that if cities in states like Arizona or Georgia were to lose electricity — either due to high winds, a hurricane, an overwhelmed grid, or even a cyberattack, all of which are increasing in prevalence — during a heatwave, over ten of thousands of people could die. Further, hundreds of thousands would require emergency care from providers that presently do not have the capacity to fulfill demand. Those who are most vulnerable to such a catastrophe include the elderly, those who are pregnant, outdoor workers, and those who reside in redlined communities — which are overwhelmingly populated by people of color. 

While heat’s propensity to kill should be enough to draw attention, its economic consequences can also be dire. In the United States alone extreme weather brings annual costs of more than $100 billion. Lower productivity and increased absenteeism due to heat (especially in the labor-intensive agricultural and manufacturing sectors) has led to price increases, and as extreme weather continues to overwhelm aging US infrastructure and affects a greater share of vulnerable workers, these costs will skyrocket to more than $500 billion a year by 2050.

Broiling Abroad

But nowhere are the effects of heat waves more apparent than in South Asia, where the security, political, and economic effects of extreme heat are being seen most viscerally today. As is the case in the United States, the deaths from last month’s extreme temperatures were undercounted in India and Pakistan, both of which lack the infrastructure to accurately assess and report them. And as the consequences of a changing climate continue to unfold, the likelihood that a heatwave like this one (or worse) will affect the region will increase; currently, there is a 10% chance one could occur during any given spring. If global warming continues at the current pace, that could rise to an astounding 50% in the near future — a mere coin toss.

Not only are record-setting temperatures themselves a threat, they also serve to worsen other existing hazards, risking both US interests at home and abroad as well as global stability writ large

The potential security consequences of such a possibility affect global stability and US interests both directly and indirectly. First and foremost, tens of thousands of unnecessary deaths will come because of longer heatwaves and more intense humidity, the latter of which is particularly relevant in South Asia and may make parts of India completely unlivable. Second and as a result, an untold number of people from several of the most populated and high-density countries in the world — India, Pakistan, Bangladesh, etc. — will migrate not just within borders (as they already do) but across them. Such mass movement will increase demand for limited resources, stoke social and political tensions between local populations and countries, and increase the likelihood of conflict. 

As always, there is a monetary cost to such strife: 10 to 18% of South Asia’s GDP is at risk due in part to these phenomena. While even these abstract figures are alarming, the situation seems grimmer when considering the tens of millions of livelihoods that represents and the sort of poverty and political unrest that could result, further exacerbating instability and access to life-saving infrastructure.

In the 2021 National Intelligence Estimate — one of the only authoritative government documents on the issue — the National Intelligence Council notes that “negative health consequences,” conflict, resource strain, and mass migration pose a medium to high threat to both US interests and global geopolitical tensions more broadly. But there are indirect risks too: demand from poor states for climate financing, the perception that wealthy states are not doing enough to provide said aid, and even unilateral geoengineering all represent (or will soon represent) a medium to high risk to US interests. The report flagged South Asia as a particular region of concern to this end.

This in a region where US partners are essential to combating Chinese influence, mitigating (or bolstering) Russian aggression, and fighting terrorism is especially worrisome for Washington. Should any of them rethink their relationship with the United States because they believe Washington is not doing enough to prevent the effects of climate change their people are suffering from, it could neuter US attempts to further any of these goals and then some. Arguably just as worrisome is the possibility that China, Pakistan, and India — three of the highest populated countries in the world, all of which boast nuclear weapons — could accidentally provoke a conflict through a mishandling of climate migrants or a misguided attempt to alter the atmosphere.

Cooling Down?

Formulating a response to the devastating effects of extreme heat means first acknowledging the problem exists. At home, this means a declaration from the Federal Emergency Management Agency (FEMA) that heatwaves are major disasters in the same way that hurricanes, floods, and tornadoes are, a move that would unlock federal funds to assist states in responding to them in real-time. Relatedly, the Centers for Disease Control and Prevention (CDC) should standardize a national system for identifying and reporting heat-related deaths so policymakers can better understand the magnitude of the threat at hand and allocate sorely needed funds appropriately. Finally, the US national security apparatus should articulate the risks and opportunities climate change poses for security policy more regularly, through policy documents (e.g., the Annual Threat Assessment, National Security Strategy, etc.), speeches, and other collateral.

It is also imperative for Congress to appropriate funds to meet the funding obligations outlined by the slate of landmark infrastructure laws passed under the Biden administration: the Inflation Reduction Act, Infrastructure Investment and Jobs Act, and the CHIPS and Science Act, each of which allocates billions for climate mitigation and resilience. It will also be up to states to use those funds appropriately, which may be politically difficult in conservative-leaning states (Texas, Arizona, etc.) and in states that haven’t dealt with heat as viscerally and so are relatively unprepared for what is to come (Maine, Pacific Northwest, etc.). 

Looking abroad, cooling both temperatures and tensions means working with wealthy allies like European Union members and Japan and even adversaries like China to provide debt relief and climate financing to poorer states, who on a per capita basis contribute nearly nothing to the climate problem but suffer the most. Given the United States’ status the world’s richest nation — wealth that was generated by burning more fossil fuels than any other nation — and guarantor of the postwar world order, it is a moral and strategic imperative that Washington lead on international climate assistance.

Policy suggestions like these seem straightforward, but as the fraught COP system demonstrates, the complex international legal and geopolitical environment makes substantive multilateral climate cooperation all but impossible. Domestically, climate change is still viewed skeptically by Republicans, even if the most affected areas of the country are controlled by conservatives. To affect change at this scale, a robust consensus on the causes and effects of extreme heat and other climate disasters will be needed — something that is starting to emerge, albeit slowly, among voters.

But by the time everyone from heads of state to rural voters in the American Midwest comes to a shared conclusion, it may be too late. Mitigating and adapting to extreme heat and climate change as a whole means decisive action now, no matter the scale. Our economic, political, and environmental well-being depends on it.

Connor Sutherland

Connor Sutherland is an assistant director at the Council of Foreign Relations and a graduate student at Georgetown University.

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