A series of punishing droughts set the stage for the Syrian civil war in 2011. A drying East Africa fuels ongoing conflicts over natural resources in Somalia and Kenya. Rising seas threaten future refugee crises in Southeast Asia. Melting sea ice in the Arctic is opening new shipping lanes, creating new potential for tensions among competing powers at the top of the world.

These are among the many worries – some already realized and some forecast in the near future – that concern experts studying the convergence of climate change and national security.

The idea that a warming planet threatens stability around the globe is not a new one. The U.S. Naval War College began studying the topic as early as the late 1980s, and over the past three decades a steady stream of analyses from the U.S. Defense Department, private think tanks, and other organizations have pointed to threats that climate change poses to peace and stability. Climate change is rarely viewed as a direct cause of instability and conflict, but experts generally regard it as a “threat multiplier” – a phenomenon that can worsen or exacerbate other sources of instability and conflict, such as competition for natural resources and ethnic tensions.

Discussions generally fall into two areas: the impacts of warming on conflicts between nations and among ethnic groups within nations, and the impacts of warming on U.S. military infrastructure and operations.

Threats to global security

The Worldwide Threat Assessment of the U.S. Intelligence Community, an annual report on security threats to U.S. interests, concludes that “global environmental and ecological degradation, as well as climate change, are likely to fuel competition for resources, economic distress, and social discontent through 2019 and beyond.”

“Climate hazards such as extreme weather, higher temperatures, droughts, floods, wildfires, storms, sea-level rise, soil degradation, and acidifying oceans are intensifying, threatening infrastructure, health, and water and food security,” the authors of the January 2019 report wrote.

Extreme weather events, worsened by accelerated sea-level rise, will hit some areas particularly hard – including South Asia, Southeast Asia, and the Western Hemisphere. Water and food insecurity made worse by heat waves, droughts, and floods are already increasing the risk of conflict in Egypt, Ethiopia, Iraq, and Jordan, according to the report.

The Worldwide Threat Assessment also highlighted the risk of tensions between Russia and China as sea routes open up in the Arctic and the rush for natural resources at the top of the world increases.

Threats to military infrastructure & operations

Responding to a Congressional order in late 2017, the Defense Department issued a report in January of 2019 that outlined impacts of climate change on Defense Department missions, operational plans, and installations. It offers an authoritative overview of past, present, and future concerns.

Among them: In the United States Africa Command, rainy season flooding and drought and desertification can complicate the execution of missions. At Naval Base Guam, flooding driven by sea-level rise can negatively affect submarine squadron operations, telecommunications, and other support activities for naval operations.

Meanwhile, a warming climate is significantly impeding military testing and training, with an increased number of suspended, delayed, or canceled outdoor events – particularly at installations in the United States’ Southeast and Southwest.

Increased maintenance and repair of installations has been required: The report cites wildfires in the Western U.S. impacting Vandenberg Air Force Base and the Point Mugu Sea Range, hurricanes causing damage and delays at Tyndall Air Force Base in Florida, permafrost thawing impacting operations at Fort Greely in Alaska, and rising seas contaminating freshwater supplies at atoll installations in the Pacific.

While these two key government reports summarize some of the latest thinking on climate change and national security, they are backed up by a deep well of information on the topic. Climate scientist and author Peter Gleick has compiled a list of important assessments (updated regularly) at his blog.

Below are links to several key articles, reports, and organizations focused on this important and complex topic:

Coverage of the 2019 release of the Worldwide Threat Assessment:

U.S. Intelligence Officials Warn Climate Change Is a Worldwide Threat: Their annual assessment says climate hazards such as extreme weather, droughts, floods, wildfires and sea level rise threaten infrastructure, health and security.

Coverage of the 2019 release of the Defense Department report on climate change and military operations:

Pentagon Confirms Climate Change Is A National Security Threat, Contradicting Trump: The military walks a fine line between the White House’s official climate denialism and the stark realities of a warming planet.

Other key reports:

Chapter 16 of the National Climate Assessment: Climate Effects on U.S. International Interests

The Impact of Sea-Level Rise and Climate Change on Department of Defense Installations on Atolls in the Pacific Ocean, 2017

Department of Defense Climate Change Adaptation Road Map, 2014

Department of Defense Quadrennial Defense Review, 2014

Yale Climate Connections news stories, podcasts, and videos:

Why climate change is a ‘threat multiplier’: Extreme weather and water shortages increase the risk of political instability and terrorism. (June 20, 2019)

Climate change poses security risks, according to decades of intelligence reports: Intelligence analysts have agreed since the late 80s that climate change poses serious security risks. (April 8, 2019).

Retired Navy rear admiral calls extreme weather a national security threat. (November 12, 2018)

New monthly video explores climate, drought, and national security: A number of current and likely future “geopolitical hotspots” are facing increased climate-related stresses, heightening concerns among military experts and policy makers. (November 10, 2015)

Additional News stories:

Trump skepticism: Pompeo ‘can’t rank’ climate change on list of national security threats (May 5, 2019)

Hearing on climate change and national security becomes an angry partisan clash (April 9, 2019)

Germany pushes climate change as security risk (April 6, 2019)

White House climate panel to include a climate denialist (February 20, 2019)

U.N. warns climate change impacts security, U.S. ignores link (January 26, 2019)

The Pentagon calls climate change a national security threat (January 18, 2019)

106 Lawmakers urge Trump: Restore climate change in national security strategy (January 16, 2018)

Select sites and journal articles:

The Center for Climate & Security

Climate change and national security, Part I: What is the threat, when’s it coming, and how bad will it be? (The Lawfare Institute) (November 19, 2018)

Climate change and national security, Part II: How big a threat is the climate? (The Lawfare Institute) (January 7, 2019)

The national security impacts of climate change (Journal of National Security Law & Policy) (December 19, 2018)

Why climate change is a national security issue (JSTOR Daily) (October 25, 2018)