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Linked Threats to Humanity: How Nuclear Weapons and Climate Change Are Connected

Among the threats to human life, nuclear weapons and climate change pose dangers that set them apart from many others. Nuclear weapons and climate change not only can kill people but can radically alter the planet in devastating ways. They can both kill and hurt people in the present and change our world in ways that cut off or shorten the lives of generations to come. Nuclear weapons and climate change are also linked because each can reinforce the threat the other poses, in a vicious circle. 

As the world marks Earth Day, we would do well to consider the threats posed to people and our planet by nuclear weapons and climate change, how these twin threats aggravate each other, and the need to protect humanity and the environment from both.

Mutually Reinforcing Destruction

Nuclear weapons and climate change can reinforce each other’s threat in at least four distinct ways: 

  1. Climate change and extreme weather events can contribute to nuclear pollution by dispersing nuclear waste or other nuclear-related materials into the environment. 

  2. Climate change may contribute to international tensions and conflict, increasing the likelihood of nuclear war.

  3. The vast sums spent on nuclear weapons and the military divert resources away from addressing climate change.

  4. Nuclear war can have a catastrophic effect on Earth’s climate.

Climate Change and Nuclear Pollution. Nuclear weapons have had toxic consequences across their production and use. Mining uranium, processing uranium and plutonium, and testing nuclear weapons have all polluted the environment, with terrible results for people and ecosystems alike. Moreover, these activities have left behind toxic materials that still threaten communities today. 

As climate change produces more extreme weather events, the risk grows that such events may disrupt deposits of nuclear-related materials and spread them more widely. The world received a reminder of this risk in February 2024, when wildfires in Texas came close to the Pantex complex near Amarillo. Pantex has historically been a site for assembling nuclear weapons and today is a storage center for plutonium. 

The wildfires caused a pause in operations and a partial evacuation at Pantex. Although the fires never reached the complex, the incident suggests that facilities handling highly dangerous materials are vulnerable to the types of disruptive events climate change makes more common.     

A still more alarming reminder of this problem exists in the Marshall Islands. A major US nuclear testing site during the Cold War, the Marshalls is now home to more than 3 million cubic feet of radioactive waste produced by such tests. This waste, which includes lethal amounts of plutonium, is currently housed in an aging concrete structure known as Runit Dome. As sea levels rise because of climate change, the ocean could break open the structure, releasing its contents.     

Michael Gerrard, a legal scholar at Columbia University, comments, “More than any other place, the Marshall Islands is a victim of the two greatest threats facing humanity — nuclear weapons and climate change.” 

Climate Change and Conflict. Peace and environmental groups have identified the disruptions from climate change as contributing to world conflict. The International Campaign to Abolish Nuclear Weapons (ICAN) points to how climate change threatens access to food and water, leading to armed conflict and refugee crises. “The resulting global instability,” ICAN comments, “is increasing the danger of nuclear war.” A 2013 survey of 50 studies on the topic similarly found “strong support for a causal association between climatological changes and conflict across a range of geographies [and] a range of different time periods.”

For example, researchers have argued climate change led to a 2006-2009 drought in Syria. Over 1 million people subsequently migrated to cities. The resulting social stresses may have contributed to the 2011 uprising and civil war. Tensions between nuclear-armed nations India and Pakistan are aggravated by conflict over shared water supplies, a conflict that climate change may worsen. 

Granted, whether climate change is linked to conflict is a highly controversial question. Some have disputed the link. Further, even if the two problems are linked, we should not assume climate change inevitably fosters conflict. To do so risks falling into a fatalistic attitude that regards conflict as unavoidable amid a changing climate. This attitude could become a self-fulfilling prophecy. Instead, we should recognize that even in a warming, weather-stressed world, humans still have choices about whether to respond violently to problems. 

We should not assume climate change automatically leads to conflict. Rather, we should be aware that climate change may aggravate political tensions and make peaceful conflict resolution more difficult. This possibility is reason enough for peace activists to be concerned about climate change.

Diversion of Resources. The United States is currently working to upgrade its nuclear weapons arsenal. This “modernization” program has been marked by spiraling costs, with a 2023 Congressional Budget Office report estimating the program would cost $756 billion over a decade. Further, nuclear modernization is just part of US military-related spending. The Biden administration’s current national security budget request is $895 billion

These hundreds of billions spent on nuclear weapons and the military are funds that could be spent on sustainable and green technologies or other efforts to counter climate change. When one considers the money spent by other nuclear-armed nations on their arsenals, the opportunity cost grows still larger.

Further, the hawkish policies of the United States and other nations involve another, more abstract but real, opportunity cost. An emphasis on military competition with other nations, with all the accompanying mutual suspicion and hostility, severely hampers nations’ ability to cooperate on addressing climate change. The unfolding Cold War between the United States and China, for example, will, if left unchecked, consume political attention and energy that could be put to more constructive uses.

Nuclear Climate Catastrophe. Using nuclear weapons in war would not only kill enormous numbers of people but would wreak havoc on Earth’s climate. 

Multiple studies have modeled the effects of global nuclear war or even a more limited nuclear exchange. These studies have indicated that nuclear war would throw huge amounts of soot into Earth’s upper atmosphere, cooling the planet—one study estimates global average surface temperatures would fall by more than 15 degrees Fahrenheit. This global cooling would disrupt food production on land and in the sea.

A 2022 study in Nature Food concluded that “the reduced light, global cooling, and likely trade restrictions after nuclear wars would be a global catastrophe for food security.” The authors projected that the global cooling caused by a nuclear war between India and Pakistan could lead to over 2 billion people dying. A nuclear war between Russia and the United States could lead to over 5 billion deaths.

As dire as the current climate situation is, these analyses indicate the far worse climate consequences of nuclear war. Nuclear weapons pose the greatest climate change threat of all.

Countering Linked Threats

Nuclear weapons and climate change pose monumental, linked threats to humanity and the earth. While peace activists and environmental activists will naturally have their respective areas of specialization, both groups should remain aware of both threats and their connections. Both groups should support each other in their efforts to counter these linked threats. The success of these peace and environmental efforts will determine our future—or rather, whether we have one.


Disclaimer: The views presented in the Rehumanize Blog do not necessarily represent the views of all members, contributors, or donors. We exist to present a forum for discussion within the Consistent Life Ethic, to promote discourse and present an opportunity for peer review and dialogue.

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