By Robert L. Ostergard, Jr. and Nicholas Seltzer

The links between climate change and health security have been under investigation for decades. However, at its core, linking climate change to health security faces a number of complex obstacles, most of which are linked to the indirect nature and the temporal challenges in the relationship. This relationship has significant ramifications for people and states that include the impact on bioorganisms and viral transmission, agriculture and food supplies, and social interactions such as poverty, migration, and conflict. This article provides an overview of the complex relationships that emerge from the climate change and health security nexus, while serving as an introduction to the wide-ranging articles that appear in this volume. We conclude with policy recommendations and implications of the climate change and health security relationship.