Climate change (CC) can be defined as a long-term shift in global, continental, and/or local climate patterns. Although many equate CC to the rise in global temperatures, the issue is much more complicated and involves a large number of interconnected factors. Among some of the less discussed considerations of CC are its effects on a broad range of public health issues, including the emergence of novel infectious diseases, the encroachment of infectious disease vectors into previously unaffected geographic distributions, and crop failures resulting in threats of malnutrition and mass migration. This chapter will be devoted to key issues related to CC in the context of international health security (IHS).