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Climate Change Is the Biggest Threat to US National Security

By not approaching environmental threats with the same zeal as it does its adversaries, the US is leaving itself more vulnerable to climate change.

Words: Connor Sutherland
Pictures: Markus Spiske

If one found themselves in the Pentagon last month and looked out one of its nearly 80,000 windows, they might have been shocked to see not the adjacent lagoon or the Potomac River, but nothing at all. And instead of the usual scenic skyline in New York, residents posted photos of a city that looked straight out of Denis Villeneuve’s Blade Runner 2049

The dangers were more than fictional: the entire northeastern United States was covered in smoke from wildfires in Quebec that had been blown southward by a storm near Nova Scotia. And while Canada’s fire season typically runs between May and September, its forests have never burned this much and this quickly. An area larger than the state of Maryland has been lost over the last month. Climate change is to blame: longer dry seasons leave more time for land to burn, and shifting global weather patterns caused by a rapidly-warming Arctic weaken countervailing climate forces.

The result is not just a massive tinderbox in Canada, but an entire adjacent coast smelling like a campfire with the air quality and visibility to match. The atmosphere in New York had never been so toxic, and residents in the nation’s capital were advised to stay indoors as part of a rare Code Purple warning. Suddenly, conditions that were only thought possible in West Coast states like Washington, Oregon, and California are present on both sides of the country.

And while the sights are shocking, they should not be a surprise. A warming planet means more extreme and unpredictable weather, from heat waves and droughts to heavy rains and floods. As Earth warms beyond the Paris Agreement threshold of 1.5 degrees Celsius above pre-industrial levels (as a recent synthesis report from the UN-sponsored Intergovernmental Panel on Climate Change asserts is all but certain to occur), experts have long attested that this trend will only grow in intensity and unpredictability. 

The consequences will be felt by all — even the wealthiest among us need oxygen (and they’ll pay through the nose to get it). But the effects will — and already do — disproportionality fall on poor and marginalized communities in wealthy countries and on developing nations more generally. The political, economic, and security implications of this planetary transformation will be profound and leave no corner of the world unscathed.

Boiling Point

The implications of this future for both US interests abroad and stability at home are palpable. In the first-ever National Intelligence Estimate on Climate Change (NIE) and the most recent Annual Threat Assessment, the intelligence community highlights more than a dozen climate-driven geopolitical risks to US national security: demands for climate financing from developing nations, climate-fueled migration and instability in poor regions, competition for food and energy resources, and global perception of US leadership on climate change. The NIE highlights sub-Saharan Africa and Southeast Asia as regions of particular concern.

The National Defense Authorization Act allocated nearly $900 billion for DOD (a record), a chunk of which will fund the Beltway’s continued obsession with great power competition with China and Russia, but did not include a single mention of climate change.

At home, climate-amplified wildfires and hurricanes are leaving parts of the country functionally uninhabitable, as public and private insurance companies begin to refuse homeowner coverage in regions plagued by longer fire seasons and more frequent tropical storms. Wild temperature fluctuations and unprecedented precipitation are overwhelming aging electric grids and other infrastructure in densely populated areas throughout the country, killing hundreds and raising public health concerns. In high-growth cities like Phoenix, inadequate cooling and a lack of public health infrastructure could leave hundreds of thousands of people vulnerable to the sort of heatwave-related blackouts growing in frequency and intensity.

Perhaps the alarming case of climate risk in the United States, though, is one of drought. The bureaucratic fight between Arizona, California, Nevada, and Washington over the Colorado River finally concluded this spring with a deal for the latter to pay the states to use less water. But the compromise is a short-term fix — it is only valid through 2026 — and the river will continue to decline even before the agreement expires. If a more comprehensive one is not reached before that point, the main source of water that nourishes tens of millions of people could be in jeopardy, and along with it, the region’s roaring economic engine and robust energy resources. 

Missing the Forest and the Trees

Given, then, the dangers climate change poses to US political, economic, and physical security at home and abroad, one might think that the White House, Congress, and Department of Defense (DOD) — the principal agency charged with safeguarding US interests and prosperity from external threats — would have a comprehensive plan for confronting the climate crisis. 

But this year’s National Defense Authorization Act (NDAA), a summary of which was recently released by the Senate Committee on Armed Services, includes not a single mention of climate change. The bill allocated nearly $900 billion for DOD (a record), a chunk of which will fund the Beltway’s continued obsession with great power competition with China and Russia, especially as it relates to a potential Taiwan contingency and Russia’s war in Ukraine. The summary states that such programs will support “defending the US homeland.”

And while China and Russia certainly pose risks to US interests and to global stability more broadly, Beijing and Moscow are not invading the homeland to destroy American infrastructure, threaten domestic food supplies, and endanger tens of thousands of lives — at least not directly. But climate change is, and all any Pentagon strategist has to do is look out their office window to see (and smell) the threat unfolding in real time. 

Of course, to contrast itself with the previous White House occupant, the Biden administration has pained itself to be more vocal about how climate change is affecting force readiness and national security, first with a statement from Defense Secretary Gen. Lloyd Austin soon after taking office and then with the 2022 National Defense Strategy.

As welcome as these policy developments are, they only acknowledge the risks climate change poses to DOD operations: damage to military installations and warfighting materials, impact on logistics and transportation, and so on. This White House, in other words, is continuing the policies of the last one by recognizing that climate change presents challenges to national security and international stability, but does not constitute a threat to them. 

The distance between those two sentiments is planet-wide. By refusing to approach threats to the environment with the same zeal as it does adversaries like China and Russia, Washington is leaving the United States, its allies, and indeed the entire world more vulnerable to the consequences of climate change. The result will be — and already is — greater instability and inequity at home and abroad, a world order more hostile to US interests, and a more intolerable mode of existence for humanity in general.

Preparing for Consequences 

The solution is not to catapult the defense budget into the trillions with funding for climate governance programs and economic statecraft. If Beltway policymakers have learned anything over the last 20 years, it is that the Pentagon is not a device for state-building. The framing of climate change as a security problem has been met with skepticism from developing nations and scholars alike — and for good reason. 

Weaponizing a threat that knows no borders and has no enemy will only serve to deny countries and stakeholders that lack the military capabilities of a great power (i.e., the United States, China, etc.) any agency to grapple with the problem and contribute to a solution. Much like Washington excluded Ba’athists from rebuilding Iraq after the United States invaded in 2003 and blackballed Kabul from negotiations with the Taliban to facilitate a US exit from Afghanistan, treating climate change as a purely security problem with a principally military solution will exacerbate its risk to the most vulnerable populations (who had no part in causing the problem to begin with) and further erode US influence globally. 

Instead, the White House should use documents like the National Security Strategy to declare climate change as a principal threat to national security, a solution for which must emphasize diplomatic inclusion and economic cooperation, particularly with heavy polluters like the EU, Russia, China, and India as well as developing states in Central America, sub-Saharan Africa, and Southeast Asia. 

The administration could, for instance, exercise the institutional influence it derives from its outsized shares in both the World Bank’s capital funds and the International Monetary Fund to forgive the debt of states at risk of distress, especially in high-growth, high-risk regions like Southeast Asia and sub-Saharan Africa. Such a move has rich precedent and would create fiscal space for domestic infrastructure programs and improve creditworthiness, unlocking trillions in private financing and trillions more in public investments. It would also improve American international credibility on the issue and even support a diplomatic rapprochement with China. 

The president and Congress should also supercharge agencies like the US Agency for International Development, the International Development Finance Corporation, the Millennium Challenge Corporation, and the Export-Import Bank with tens of billions in funding to support building renewable energy and adaptation infrastructure via grants and low-interest loans. Eventually, these funding levels should equal at least the $100 billion in annual climate finance long promised to developing nations. 

The United States has contributed more than any other nation to the proliferation of the climate threat, and Washington’s response to it must be mindful of its scope and magnitude.

To undergird this aid-as-national-security approach to climate diplomacy, policymakers should task DOD with providing the rigorous analysis, scientific innovation, and logistics expertise that is the hallmark of their operations. Understanding where climate risks are greatest, what threats they pose to US interests, what is needed to mitigate or adapt to the threat, and the logistics of a potential response can help US diplomats and policymakers negotiate from a position of strength — an edge that will be particularly useful when dealing with Beijing, Moscow, and other great powers.

While these suggestions are not at all novel and fit well within the historical mandate of the Beltway national security apparatus, the capabilities to do so have never been deployed in a climate context. To streamline interagency cooperation and build the necessary processes to carry out these operations, Congress should establish an assistant secretary of defense (ASD) for the environment position within the Under Secretary of Defense for Policy’s office. Doing so would give environmental threats the sort of bureaucratic attention already given to more traditional risks like China, and could serve as the point of coordination with the State Department’s under-secretary for economic growth, energy, and the environment and other agencies. Such a change may seem drastic, but there is recent precedent to draw on: the ASD for Space Policy position was established just three years ago.

Finally, as geopolitical risks and diplomatic tensions over climate increase, Congress should mandate the Office of the Director of National Intelligence to release an assessment (similar to the 2021 NIE report) on those developments and the threats they pose to US interests every two years to policymakers and the public. Such frequency will help to galvanize attention from consumers in and out of the government and thus promote a more inclusive approach to formulating solutions.

Measures like these are necessary due to the nature of the climate threat, which is truly planetary and knows no boundaries: carbon emissions in one area of the world will affect the environment everywhere else. Facilitating aid to highly vulnerable regions and states with exploding energy demands will help prevent further warming and its cataclysmic implications, thus protecting Americans at home and US interests and geopolitical standing abroad. Washington has made historic investments in domestic clean energy and adaptation programs via the Inflation Reduction Act, the CHIPS and Sciences Act, and the Bipartisan Infrastructure Law, but these programs will be for naught if not paired with comparable actions elsewhere.

Time to Prioritize 

When Vice Chair of the US Secretary of State’s International Security Advisory Board Sherri Goodman first referred to climate change as a “threat multiplier” in a 2007 Center for Naval Analysis report, she introduced environmental considerations as a risk factor that policymakers should take seriously when articulating national security strategies. This is to say that societal awareness of global warming was much less than it is today (the Al Gore documentary “An Inconvenient Truth was released just a year before her statement), and our understanding of the problem was limited by our lack of attention to it and our technological abilities of the day.
But as the technologies scientists use to model climate change trends continue to grow more sophisticated and our collective understanding of the problem becomes more widespread, so too should the ways in which practitioners frame climate change as a national security concern. To limit the context in which policymakers develop and implement US foreign policy in a world imperiled by climate change is to risk being unprepared for its consequences. The United States has contributed more than any other nation to the proliferation of the climate threat, and Washington’s response to it must be mindful of its scope and magnitude. Indeed, anything less is a danger to all life on Earth.

Connor Sutherland

Connor Sutherland is the program associate in the Council of Foreign Relations’ Washington Meetings and Independent Task Force Program.

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