The emergence of infectious disease outbreaks is the result of complex dynamics influenced both by environmental conditions conducive to the development and spread of infectious agents and by the increasing pace of technological, social, and demographic changes. This article aims to analyze these interactions from two perspectives. The first examines the overall dynamics of the epidemic cycle and, in particular, explores the impact of human activity on the emergence and spread of epidemics. The second concerns the interactions between certain pressures exerted on the environment and the increased vulnerability of populations to infectious epidemics. This analysis advocates for strengthening actions that integrate environmental protection, the sustainability of our production methods, and the quality of our relationship with nature. This integration will result in major co-benefits for public health and global health.