Sensemaking and Security: How Climate Change Shapes National Security

Climate change has evolved from an environmental issue, to an energy problem, to a security threat with an impending sense of urgency. It is increasingly recognized as having national security implications with multifaceted national security risks. Climate change increases the intensity and frequency of extreme weather events that threaten nations’ territorial integrity and sovereignty. For example, rising sea levels cause both internal displacement within nations and climate-change refugees across national borders. Some of the climate change threats facing the world in 2020 include droughts, wildfires, floods and global pandemics. Each one has the potential to increase competition and conflict around the world, creating more instability than ever. With many military bases susceptible to these threats, the changing climate has been a focus of military planners for many years. The National Defense Strategy (NDS), the primary planning document that guides decision making within the United States military, emphasizes climate change as a major factor in an increasingly complex security environment. Climate change will likely increase instability and insecurity within already vulnerable regions, particularly in regard to its destructive impacts, as rising seas infiltrate coastal bases, hurricanes batter installations, and wildfires infringe on training ranges and impact readiness. This chapter provides an analysis of climate change as a national security issue in the context of climate science and climate change’s multifaceted security effects with an emphasis on the most disaster-prone regions of Asia and the Pacific.