The Quadrennial Homeland Security Review (QHSR) was released by the Department of Homeland Security (DHS) on June 18, and it takes a hard look at the security risks of a changing climate.

Most significantly, climate change appears in the QHSR’s section on “Prevailing Challenges that Pose the Most Strategically Significant Risk” on page 28.  In that context, “natural hazards…with increasingly variable consequences due in part to drivers such as climate change and interdependent and aging infrastructure” shares the stage with other significant homeland security risks, including “the terrorist threat,” “cyber threats,” “biological concerns,” “nuclear terrorism,” and “transnational criminal organizations.”

Also of significance is the inclusion of climate change in the document’s “Potential Black Swans” list on page 29 (in other words, low-probability, high-impact risks). The QHSR identifies: “Abrupt impacts of climate change, such as drastic alterations in U.S. weather patterns and growing seasons or rapid opening of the Arctic” as one of only four such black swans, making it a very significant inclusion. Interestingly, one of the other black swans mentioned is “technology-driven changes to manufacturing processes, such as three-dimensional printing,” which though presenting potentially disruptive challenges to existing flows of information and goods, also offers an opportunity for enhancing climate resilience (as we detail in our briefer “The U.S. Military, 3D Printing and a Climate Secure Future).”

Lastly, the QHSR’s section on “The Strategic Environment,” highlights “Drivers of Change” that can present “threats to the Nation’s homeland security interests.” The QHSR highlights “natural disasters, pandemics and climate change” as one of six key over-arching drivers, including “the evolving terrorism threat,” “information and communications technology,” “interdependent and aging critical infrastructure systems and networks,” “flows of people and goods: increasing volume and speed,” and “budget drivers.” Under the heading of “natural disasters, pandemics and climate change” the document has the following to say on security risks that may arise from climate change dynamics ( and “associated trends”:)

Page 21: Natural disasters, pandemics, and the trends associated with climate change continue to present a major area of homeland security risk.

Page 21-22: Weather events present a significant and growing challenge, with several multi-billion dollar disasters in recent years. Hurricane Sandy, the largest diameter Atlantic storm on record, is estimated to have killed 117 people in the United States and caused widespread flooding. More than 8.5 million people were left without power, and the storm caused tens of billions of dollars in damage. Other disasters, particularly earthquakes, droughts, and floods, also pose significant risks to the Nation. The risk of these disasters is increased by the vulnerability of aging infrastructure, increasing population density in high-risk areas, and in the case of droughts, floods, and hurricanes by trends associated with climate change. 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.

Page 22: 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.

In all, the QHSR demonstrates that the homeland security risks associated with climate change are severe, and just as concerning as security risks we often hear about, such as evolving international terrorism and cyber-threats. This reaffirms the reality that climate change presents threats that are not just limited to the natural environment. The safety and security of the United States homeland is at risk as well. Acknowledging this risk is an important step in both preventing and preparing for disruptive climatic changes.