The Waters Could Claim Nuclear Weapons

On March 15, 2019, floodwaters breached the gates of Offutt Air Force Base. Two days later, one-third of the base was inundated—and at least $1 billion worth of damage done.

Offutt is perhaps best known as the home of U.S. Strategic Command (STRATCOM), the central node of the country’s nuclear command-and-control system. While the flood stopped short of STRATCOM headquarters, this incident paints an all-too-clear picture about the potentially catastrophic ways climate change and nuclear weapons could intersect.

Most nuclear-armed states are undertaking significant efforts to modernize their nuclear programs. Their goal? Ensuring their arsenals remain viable deterrents for decades to come, prepared to address a changing geostrategic environment. But can their arsenals continue to deter in a rapidly changing geophysical environment?

Climate change could hit every leg of the U.S. nuclear triad hard. Sea level rise, extreme flooding, and extreme heat could challenge U.S. ballistic missile submarines (SSBNs), intercontinental ballistic missiles (ICBMs), and bomber aircraft; the infrastructure for their basing; and the personnel who operate them.

At the Naval Submarine Base Kings Bay, for example, rising sea levels and flooding could significantly affect the Navy’s capacity to service and maintain the submarines. Under various climate change scenarios, rising waters could inundate facilities throughout the base, disrupting SSBN servicing and crew exchanges and compromising roads connecting a key missile facility to the waterfront—potentially delaying the transport and maintenance of the submarines’ nuclear missiles. These issues would only get worse if climate change effects prevented the submarines from entering port. Since Kings Bay is one of only two bases equipped to support SSBNs, this could have serious repercussions for the broader health and stealth of the fleet.

Elsewhere, warming temperatures may accelerate extreme flooding that could limit access to ICBM silos and facilities at Minot Air Force Base—not to mention displace base personnel and their families, such as with what occurred during the devastating Souris River flood of 2011. This could disrupt the base’s staffing and maintenance operations, with potential cascading effects for the ICBM leg of the triad if delays in critical, time-sensitive maintenance such as the replacement of limited-life components reduce the reliability of some missiles.

Projected increases in extreme heat conditions and flash flooding at Whiteman Air Force Base—home to the nation’s B-2 stealth nuclear bombers—pose potential risks to the aircraft. These climate effects could limit the times and conditions under which the bombers can freely take off from or land at Whiteman, which could have implications for the readiness of the larger bomber fleet, especially if the aircraft couldn’t access relevant nuclear weapons storage sites.

But the impact could be even more significant in other nuclear states that are already feeling the effects of extreme climate hazards—and have less robust infrastructure than the United States. Take North Korea and Pakistan, both of which have experienced severe flooding in recent years. In 2020, the Kuryong River in North Korea spilled its banks and threatened the Yongbyon Nuclear Scientific Research Center, which contains many nuclear weapons-related development and production facilities. Because key reactors were offline at the time, flood-induced damage to the dam that helps ensure a constant reservoir for the reactors’ cooling systems didn’t inflict much harm—but projections suggest North Korea might not be so lucky in the future.

In a worst-case scenario, a flood could disrupt online reactors from functioning safely or even damage on-site facilities that store nuclear materials, which, if not contained, could release radioactive hazards into the environment.

In 2022, record-breaking floods in Pakistan submerged a third of the country, wreaking havoc on food security, health care, and critical infrastructure. While the country’s nuclear energy facilities were spared, southern regions, where experts suspect nuclear weapons sites are located, were among the most devastated. Climate change is only expected to cause more extreme precipitation events, bringing further risk with it.

And these aren’t the only states at risk, nor are floodwaters the only danger. Wildfires that have previously threatened Russia’s nuclear sites are likely to get worse with more extreme heat. The United Kingdom, which relies only on SSBNs operated out of a single coastal base, may be particularly vulnerable to the effects of sea level rise. And India’s coastal nuclear facilities are projected to face more intense cyclones as global temperatures rise.

A shifting world will also likely affect where nuclear weapons are deployed. Leading climate security experts have been warning about rising temperatures and tensions in the Arctic for years. Russia has already been bolstering its Arctic military infrastructure, including through an increasing concentration of nuclear assets in the region—as well as displays of nuclear capabilities.

Meanwhile, the United States may look to increase its own Arctic nuclear activity. For instance, it is not currently known to conduct SSBN patrols in the region, likely because of associated challenges—to launch a nuclear weapon, a submarine would have to break through thick layers of ice, a time-consuming maneuver that risks damage to the multibillion-dollar submarines. An ice-free Arctic environment, however, might change Washington’s calculus, leading it to expand its deterrent patrols to the region due to potential operational advantages such as reduced attack warning times.

And yet, climate change may also present new opportunities for risk reduction. If all nuclear-armed states are vulnerable to climate impacts on their nuclear arsenals, they may be mutually interested in adopting measures to reduce associated risks. At minimum, this could entail a dialogue on best practices for assessing and mitigating climate change challenges to their nuclear programs. The dialogue could open up avenues for cooperation, such as sharing the latest climate research, to help states better prepare to address these common challenges.

More ambitiously, common climate change vulnerabilities could also incentivize arms control, as nuclear-armed states will face mounting financial pressures in ensuring the safety, reliability, and resilience of their arsenals to climate change impacts. The U.S. Department of Defense, for example, estimates that taking measures to increase just one base’s resilience to coastal flooding alone would cost at least $44.65 million. Accounting for all the measures necessary to increase the resilience of all their nuclear facilities and systems, states may find it mutually beneficial—and fiscally necessary—to reduce the size of their arsenals.

Climate change is very unlikely to undermine the complex web of facilities, bases, and operations involved in nuclear programs and their deterrence missions. But even small incidents and accidents are potentially devastating. After all, increased force vulnerability is widely recognized as a driver of escalation risks.

More concerted efforts must be made to assess these challenges—and potential opportunities—and equip states with the knowledge and insight they need to mitigate and adapt. Given the already high stakes and risks of nuclear weapons, failing to do so is not an option.