This chapter discusses the effect of climate change on the spread of diseases including plague pandemics. It starts by discussing how climate change can cause the spread of diseases through its effect on the lifecycle and distribution of pathogens, vectors, and hosts. The chapter covers the scientific evidence for the association between climate change and the plague. Then, it narrates the stories of the climate-induced pandemics that occurred in human history. These include the Antonine Plague, the Cyprian Plague, the Justinian Plague, the Black Death, the Third Plague, and the Spanish Flu. The chapter discusses the events that occurred during the time of the spread of the disease, its effect on societies that were afflicted by these epidemics and pandemics, and the scholarly evidence on the contribution of climate change to that spread.