ing the relationship between climate change and outcomes relevant to U.S. national security? What is the basis for this knowledge and how strong is it? What research and measurement strategies would strengthen the basis for this knowledge?” In response to this charge, this report presents a conceptual framework for addressing such issues, offers an evaluation of the available evidence, identifies key factors linking climate change phenomena to security concerns, and offers conclusions and recommendations related to: (a) improving understanding of climate–security linkages; (b) improving monitoring and analysis of the factors linking climate change to social and political stresses and to security risks; and (c) improving the ability to anticipate potential security risks arising from climate phenomena.
As the study developed, and upon consultation with the study’s sponsors, we focused our efforts in three specific ways. First, we focused on social and political stresses outside the United States because such stresses are the main focus of the intelligence community. Second, we concentrated on security risks that might arise from situations in which climate events (e.g., droughts, heat waves, or storms) have consequences that exceed the capacity of affected countries or populations to cope and respond. This focus led us to exclude, for example, climate events that might directly affect the ability of the U.S. military to conduct its missions or that might contribute directly to international competition or conflict (e.g., over sea lanes or natural resources in the Arctic). We also excluded the security implications of policies that countries might undertake to protect themselves from perceived threats of climate change (e.g., geoengineering to reduce global warming or buying foreign agricultural land to ensure domestic food supplies). These kinds of climate–security connections could prove highly significant and deserve further study and analysis. They could also interact with the connections that are our main focus; for example, an action such as buying foreign agricultural land might go almost unnoticed at first, only creating a crisis when the country where the land is located experiences a crop failure it cannot manage with imports. Third, we concentrated on the relatively near term by emphasizing climate-driven security risks that call for action by the intelligence community within the coming decade either to respond to security threats or to anticipate them.
Although these choices of focus helped bound our study, they left it with some notable limitations. Climate change is a global and a long-term phenomenon. Events within the United States and those outside the country affect each other, indirect links between climate and conflict can be related to direct ones, and the effects of climate change will not stop beyond a 10-year horizon and, in fact, can be expected to increase at an increasing rate. Thus a complete security analysis should project the risks of climate change beyond the next decade in order to inform U.S. government security