From the Executive Summary: "Today's security environment is increasingly defined by borderless and unconventional threats, global challenges, and long-term trends. Informed by the National Security Strategy (2010) and the strategic framework established in the Quadrennial Homeland Security Review Report (2010) (QHSR), the Department's strategy methodology examines both current and future security environments to understand and reduce uncertainty associated with key trends and strategic drivers. These trends and drivers are enduring social, technological, economic, environmental, and political forces that can cause significant change in domains relevant to the Department and the Homeland Security Enterprise. Climate change is one such strategic driver. Not an end unto itself, but rather a force that is likely to shape the strategic environment, it must be accounted for in Departmental policy, strategy, plans, business processes, programs, institutional practices, and operations in order to best position the Department for success over the long term, regardless of how the future unfolds. Understanding how major strategic drivers such as climate change may evolve is at the crux of effectively and decisively managing risks to the Nation's security."
Department of Homeland Security [DHS]: http://www.dhs.gov/