A closing plenary of COP28 on Dec. 13, 2023, in Dubai, United Arab Emirates.

A closing plenary of COP28 on Dec. 13, 2023, in Dubai, United Arab Emirates. Wang Dongzhen/Xinhua via Getty Images

Why the Defense Department attended COP28

Climate change threatens our national security. We’ll face the challenge with allies and partners.

We recently represented the Defense Department as part of the U.S. delegation to the 28th Conference of the Parties of the United Nations Framework Convention on Climate Change (COP28), the global climate conference held this year in Dubai, UAE. Our delegation—the department’s second to COP in as many years—attended to discuss security implications of climate change and the energy transition.  

Acknowledging the risks to national security posed by climate change isn’t new for DOD. The link between climate change and national security has been discussed in the Pentagon’s strategic guidance documents since the George H.W. Bush administration 30 years ago. But under the Biden Administration, the Department has sharpened its focus on this challenge—and with good reason. 

DOD’s highest-level policy documents, the 2022 National Security Strategy (NSS) and the 2022 National Defense Strategy (NDS), explicitly address the national-security threat posed by climate change. The NSS labels this as the “decisive decade” for action and calls the climate crisis “the existential challenge of our time,” for it puts at risk food and water supplies, public health, and infrastructure. The NDS describes how climate change transforms the context in which our military must operate, creates new geopolitical threats, and increases demands on the force while straining our bases, equipment, and readiness.

At COP28, we engaged with allies and partners from around the world about the profound readiness, operational, and resilience challenges we all face from climate change. Many DOD partners have called climate change their number one national-security threat. They noted that increasingly severe and frequent storms, extreme heat, and persistent drought drive instability. And when instability escalates to conflict, militaries are often expected to act. 

Climate change is already increasing demands on U.S., allied, and partner forces to support civilian agency disaster response, both at home and abroad, straining the military readiness to perform core national security missions. National Guard troops from the Army and Air Force now spend more than 150,000 person-days per year responding to disasters like wildfires and flooding. Coastal installations like Naval Air Station Pensacola, Tyndall Air Force Base, and Marine Corps Base Camp Lejeune are rebuilding from damage caused by catastrophic storms, costing taxpayers billions and reducing mission readiness. Devastating floods at West Point and Offut Air Force Base compromised our ability to teach new officers and execute key strategic deterrence missions.

The need for action is simply put: adapting our forces and our installations in response to the climate crisis makes us better warfighters. The Department and each of the Services published strategies to address the climate threat, and we have taken decisive steps to build resilience against mounting climate impacts and decarbonize our operations in a way that prioritizes strengthening our operational capability. 

Energy-resilient installations allow us to continue operations even when the commercial grid goes down. More energy-efficient ground forces and combat systems mitigate risk associated with fuel logistics while more efficient airplanes increase range and payload. Hybrid-electric tactical vehicles are more agile, less detectable, and more lethal. Optimizing ship routes to improve fuel efficiency enable us to operate longer between refuelings. Investing in these capabilities makes us more resilient, agile, and lethal—we are a stronger fighting force. 

The NDS states that “mutually-beneficial Alliances and partnerships are our greatest global strategic advantage.” Partnership at all levels is essential to addressing threats posed by climate change. That is why we attended COP28—the place where the world gathers to engage on this shared challenge. In Dubai, we carried the following message: U.S. leadership on climate change—including from DOD—is essential to our collective security.