Natural calamities form a standard theme in Byzantine apocalypses. This paper discusses their function and meaning by surveying more than a dozen medieval Greek apocalyptic narratives from the sixth to the fifteenth century. It is shown that natural disasters were understood as ambiguous epiphenomena, whose ultimate meaning revolved around human agency and intentionality. Furthermore, it is argued that Byzantine apocalypses offered an intellectual strategy for coping with natural calamities by placing them into an eschatological context. This eschatologization restored epistemological control of the – seemingly uncontrollable – phenomena. Finally, it is suggested that the understanding of natural disasters as anthropogenic events is not only characteristic of medieval Greek apocalypticism but also of modern-day environmental alarmism. The paper closes with a preliminary comparison of these two hermeneutic paradigms.