Is Climate Change Actually a Threat to National Security?

Chris Carnevale | October 14, 2015 | Climate Change

In last night’s Democratic Party presidential debate, two of the five candidates on stage–Bernie Sanders and Martin O’Malley–said that climate change is one of the greatest threats to the United States’ national security. This sentiment may have come as a surprise to many Americans–conservatives and liberals alike. Are these politicians blowing the threat of climate change out of proportion? Who better to answer this question than top experts on national security, such as senior members of the military and intelligence agencies? Based on the direct quotes below from generals, admirals, Secretaries of the Departments of Defense and Homeland Security and directors of national intelligence, it is apparent that those most qualified on the subject of national security largely agree with the two candidates’ assessment of the great risk that global warming and its impacts pose to national security.

CNA Military Advisory Board (a group of 11 retired 3- and 4-star admirals and generals) , 2007 – “Projected climate change poses a serious threat to America’s national security. […] On the simplest level, it has the potential to create sustained natural and humanitarian disasters on a scale far beyond those we see today. The consequences will likely foster political instability where societal demands exceed the capacity of governments to cope. […] Projected climate change will seriously exacerbate already marginal living standards in many Asian, African, and Middle Eastern nations, causing widespread political instability and the likelihood of failed states. […] Economic and environmental conditions in already fragile areas will further erode as food production declines, diseases increase, clean water becomes increasingly scarce, and large populations move in search of resources. Weakened and failing governments, with an already thin margin for survival, foster the conditions for internal conflicts, extremism, and movement toward increased authoritarianism and radical ideologies. The U.S. may be drawn more frequently into these situations, either alone or with allies, to help provide stability before conditions worsen and are exploited by extremists. The U.S. may also be called upon to undertake stability and reconstruction efforts once a conflict has begun, to avert further disaster and reconstitute a stable environment. Projected climate change will add to tensions even in stable regions of the world. The U.S. and Europe may experience mounting pressure to accept large numbers of immigrant and refugee populations as drought increases and food production declines in Latin America and Africa. Extreme weather events and natural disasters, as the U.S. experienced with Hurricane Katrina, may lead to increased missions for a number of U.S. agencies, including state and local governments, the Department of Homeland Security, and our already stretched military, including our Guard and Reserve forces.”

CNA Military Advisory Board (a group of 16 retired admirals and generals) report update, 2014 – “The nature and pace of observed climate changes–and an emerging scientific consensus on their projected consequences—pose severe risks for our national security. During our decades of experience in the U.S. military, we have addressed many national security challenges, from containment and deterrence of the Soviet nuclear threat during the Cold War to political extremism and transnational terrorism in recent years. The national security risks of projected climate change are as serious as any challenges we have faced. […] We are dismayed that discussions of climate change have become so polarizing and have receded from the arena of informed public discourse and debate. Political posturing and budgetary woes cannot be allowed to inhibit discussion and debate over what so many believe to be a salient national security concern for our nation.”

Navy Admiral Samuel J. Locklear III, Retired Commander of the U.S. Pacific Command – “The most likely thing that is going to happen […] that will cripple the security environment, probably more likely than the other scenarios we all often talk about. […] You have the real potential here in the not-too-distant future of nations displaced by rising sea level. Certainly weather patterns are more severe than they have been in the past. We are on super typhoon 27 or 28 this year in the Western Pacific. The average is about 17. […] The ice is melting and sea is getting higher. […] I’m not a scientist, but the island of Tarawa in Kiribati, they’re contemplating moving their entire population to another country because [it] is not going to exist anymore. […] If it goes bad, you could have hundreds of thousands or millions of people displaced and then security will start to crumble pretty quickly.’’

Department of Defense, 2014, Climate Change Adaptation Roadmap – “The impacts of climate change may cause instability in other countries by impairing access to food and water, damaging infrastructure, spreading disease, uprooting and displacing large numbers of people, compelling mass migration, interrupting commercial activity, or restricting electricity availability. These developments could undermine already-fragile governments that are unable to respond effectively or challenge currently-stable governments, as well as increasing competition and tension between countries vying for limited resources. These gaps in governance can create an avenue for extremist ideologies and conditions that foster terrorism.”

2014 National Intelligence Strategy – “Many governments will face challenges to meet even the basic needs of their people as they confront demographic change, resource constraints, effects of climate change, and risks of global infectious disease outbreaks. These effects are threat multipliers that will aggravate stressors abroad such as poverty, environmental degradation, political instability, and social tensions—conditions that can enable terrorist activity and other forms of violence. The risk of conflict and mass atrocities may increase.”

Department of Defense – Quadrennial Defense Review, 2014 – “Climate change poses another significant challenge for the United States and the world at large. As greenhouse gas emissions increase, sea levels are rising, average global temperatures are increasing, and severe weather patterns are accelerating. These changes, coupled with other global dynamics, including growing, urbanizing, more affluent populations, and substantial economic growth in India, China, Brazil, and other nations, will devastate homes, land, and infrastructure. Climate change may exacerbate water scarcity and lead to sharp increases in food costs. The pressures caused by climate change will influence resource competition while placing additional burdens on economies, societies, and governance institutions around the world. These effects are threat multipliers that will aggravate stressors abroad such as poverty, environmental degradation, political instability, and social tensions – conditions that can enable terrorist activity and other forms of violence.”

Department of Homeland Security – Quadrennial Homeland Security Review, 2014 – “Natural disasters, pandemics, and the trends associated with climate change continue to present a major area of homeland security risk […] Pandemic disease, hurricanes, and other natural disasters not only have the potential to cause severe consequences, including fatalities and economic loss, but also may overwhelm the capacities of critical infrastructure, causing widespread disruption of essential services across the country. Climate change and associated trends may also indirectly act as “threat multipliers.” They aggravate stressors abroad that can enable terrorist activity and violence, such as poverty, environmental degradation, and social tensions. More severe droughts and tropical storms, especially in Mexico, Central America, and the Caribbean, could also increase population movements, both legal and illegal, across the U.S. border. Melting sea ice in the Arctic may lead to new opportunities for shipping, tourism, and legal resource exploration, as well as new routes for smuggling and trafficking, increased risk of environmental disasters, and illicit resource exploitation. Higher temperatures may change patterns of human, animal, and plant diseases, putting the workforce, the general public, and plant and animal health at higher risk of illness. The United States may need to prepare for more frequent, short-term, disaster-driven migration. Higher temperatures and more intense storms may also damage or disrupt telecommunications and power systems, creating challenges for telecommunications infrastructure, emergency communications, and the availability of cyber systems. Finally, the cost of preparing for, responding to, and recovering from such events is anticipated to grow as weather-related events continue to become more severe and damaging.

Department of Defense Secretary Chuck Hagel, 2014, Foreword to CCAR  – “Among the future trends that will impact our national security is climate change. Rising global temperatures, changing precipitation patterns, climbing sea levels, and more extreme weather events will intensify the challenges of global instability, hunger, poverty, and conflict. They will likely lead to food and water shortages, pandemic disease, disputes over refugees and resources, and destruction by natural disasters in regions across the globe. In our defense strategy, we refer to climate change as a “threat multiplier” because it has the potential to exacerbate many of the challenges we are dealing with today – from infectious disease to terrorism. We are already beginning to see some of these impacts. A changing climate will have real impacts on our military and the way it executes its missions. The military could be called upon more often to support civil authorities, and provide humanitarian assistance and disaster relief in the face of more frequent and more intense natural disasters. Our coastal installations are vulnerable to rising sea levels and increased flooding, while droughts, wildfires, and more extreme temperatures could threaten many of our training activities. Our supply chains could be impacted, and we will need to ensure our critical equipment works under more extreme weather conditions. Weather has always affected military operations, and as the climate changes, the way we execute operations may be altered or constrained. While scientists are converging toward consensus on future climate projections, uncertainty remains. But this cannot be an excuse for delaying action.”

Joint Statement of Former CIA Director and Secretary of Defense Leon Panetta and Former Secretary of Homeland Security Michael Chertoff, In 2014 CNA MAB Report Foreword – “[The report] serves as a bipartisan call to action. It makes a compelling case that climate change is no longer a future threat—it is taking place now. It observes that climate change serves as a catalyst of conflict in vulnerable parts of the world, and that projected changes in global migration patterns will make the challenges even more severe. It identifies threats to elements of National Power here at home, particularly those associated with our infrastructure and our ability to maintain military readiness. The update makes clear that actions to build resilience against the projected impacts of climate change are required today. We no longer have the option to wait and see.”

James Clapper, Director of National Intelligence, 2013 – “Many countries that are extremely important to U.S. interests, which sit in already volatile areas of the world, are living with extreme water and food stress that can destabilize governments […] Terrorists, militants and international crime groups are certain to use declining local food security to gain legitimacy and undermine government authority […] So there will almost assuredly be security concerns with respect to health and pandemics, energy and climate change. Environmental stresses are not just humanitarian issues. They legitimately threaten regional stability.”

Dr. Thomas Fingar, Deputy Director of National Intelligence for Anlaysis, Chairman of the National Intelligence Council, 2008 – “We judge that the most significant impact for the United States will be indirect and result from climate-driven effects on many other countries and their potential to seriously affect US national security interests. We assess that climate change alone is unlikely to trigger state failure in any state out to 2030, but the impacts will worsen existing problems—such as poverty, social tensions, environmental degradation, ineffectual leadership, and weak political institutions. Climate change could threaten domestic stability in some states, potentially contributing to intra- or, less likely, interstate conflict, particularly over access to increasingly scarce water resources. We judge that economic migrants will perceive additional reasons to migrate because of harsh climates, both within nations and from disadvantaged to richer countries.”


By looking at the information available from high-ranking military and intelligence agency officials, the Department of Defense, the Department of Homeland Security, we can see that the positions of Bernie Sanders and Martin O’Malley on the threat of climate change to national security are in line with top experts. The national security benefits of transitioning to a clean energy economy go beyond just mitigating the worst impacts of climate change, and also expand the security and resilience of power generation and distribution infrastructure. For these reasons and more, SACE is committed to promoting clean energy solutions to climate change and welcomes the seriousness with which the candidates seek to address one of the greatest problems of our time.

Chris Carnevale
Chris is SACE’s Climate Advocacy Director. Chris joined the SACE staff in 2011 to help with building public understanding and engagement around clean energy solutions to the climate crisis. Chris…
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