In our judgment, it would be inappropriate to conclude from the evidence reviewed here that climate change will have no effects. In fact, the evidence indicates that climate events can contribute to social and political disruption in various ways. The appropriate conclusion is as follows:
Conclusion 5.1: It is prudent to expect that over the course of a decade some climate events—including single events, conjunctions of events occurring simultaneously or in sequence in particular locations, and events affecting globally integrated systems that provide for human well-being—will produce consequences that exceed the capacity of the affected societies or global systems to manage and that have global security implications serious enough to compel international response. It is also prudent to expect that such consequences will become more common further in the future.
Conclusion 5.2: The links between climate events and security outcomes are complex, contingent, and not understood nearly well enough to allow for prediction. However, the key linkages, as with societal disruptions, seem prominently to involve (a) exposures to potentially disruptive events directly or through globally integrated systems affecting human well-being and (b) vulnerabilities (i.e., susceptibility to harm and the effectiveness of coping, response, and recovery efforts). In addition, security outcomes depend on the reactions of social and political systems to actual or perceived inadequacies of response.
Available knowledge of climate–security connections that feature societal vulnerabilities, as reviewed in this and the previous chapters, indicates that security analysis needs to develop more nuanced understanding of the conditions—largely, social, political, and economic conditions—under which particular climate events are and are not likely to lead to particular kinds of social and political stresses and under which such events and responses to them are and are not likely to lead to significant security threats.
Recommendation 5.1: The intelligence community should participate in a whole-of-government effort to inform choices about adapting to and reducing vulnerability to climate change. As part of this effort, the intelligence community and other interested agencies should support research to improve understanding of the conditions under which climate-related natural disasters and disruptions of critical systems of life support do or do not lead to important security-relevant outcomes such as political instability, violent conflict, humanitarian disasters, and disruptive migration.